Manufacturing Engineering Pune University MCQs

 This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Crystallography-1”.

1. Which of the following has a non-crystalline structure?

a) Iron

b) Quartz

c) Silica glass

d) Tungsten

Answer: c

Explanation: In general, metals exist in a crystalline form. Iron and Tungsten being metals takes up body centered cubic crystalline structure at room temperature. The ceramic compound–silica (SiO 2 ), can exist either in a crystalline form or in a non-crystalline form . While quartz, tridymite and cristobalite are known as its crystalline forms which are being differentiated based on SiO 4 tetrahedra linkage style, silica’s non-crystalline  form is just called as the silica glass.

2. Which of the following has less crystallinity?

a) Iron

b) Nickel

c) High density polythene

d) Low density polythene

Answer: d

Explanation: It is clear that, iron and nickel being metals possesses a crystalline form, whereas high density polyethylene  and low-density ethylene  are a class of polymers. These both thermoplastics are semi-crystalline nature, out of which LDPE exhibits a crystallinity of about 50-60% and HDPE of about 90%. Some people may term HDPE as crystalline, but it is more appropriate to restrict it in the category of semi-crystalline class.

3. Which of the following is a characteristic of crystalline structure?

a) High density

b) Low density

c) Range of melting point

d) Short range of order

Answer: a

Explanation: A crystalline structure has very close packing of atoms thus giving rise to high density to material it possesses when compared to its non-crystalline form. For example, quartz being the crystalline form of silica has a density of about 2.65 gm/cm 3 , whereas its ally–non-crystalline form silica glass has a density of 2.20 gm/cm 3 . For reference, the other properties being differentiated between crystalline and non-crystalline forms are tabulated below.

Differentiating Parameter Structure

Crystalline Structure Non-Crystalline Structure

Geometry Well defined geometrical shape Random shape

Melting point Definite melting point Rage of melting point

Density High density when compared to non-crystalline structure due to strong primary atomic bonding. Low density when compared to crystalline structure due to weak secondary atomic bonding

Range of order Long range of order Short range of order 

XRD Diffraction pattern Sharp diffraction pattern Broad hump

Examples Iron, Steel, HDPE, Quartz, etc. Metallic glass, silica glass, LDPE, etc.

4. Which of the following is characteristic of non-crystalline structures?

a) Long range of periodicity

b) Well defined structure and geometry

c) Low density

d) Sharp diffraction pattern

Answer: c

Explanation: In non-crystalline structure, there is no definite packing of atoms, which makes them to possess any random shape, further these atoms are being bonded by weak secondary bonds with Van der Wall’s forces, thus giving a low density to material.

5. Which of the following factor is not responsible for the formation of a non-crystalline structure?

a) Atomic packing has open structure

b) Primary bonds are absent

c) Formation of 1-dimensional chain molecule

d) Strong secondary bond

Answer: d

Explanation: A non-crystalline structure is being formed by a secondary bonds or molecular bonds are formed as a result of weak Van der Wall’s of attractions which exist between various atoms. These intermolecular bonds can be further classified as dispersion bonds, dipole bonds, hydrogen bonds, which are all should be considered as weak secondary bonds.

6. Which of the following axis system is being satisfied by cubic crystal system?

a) a = b = c, α = β = γ = 90 o

b) a ≠ b = c, α = β = γ = 90 o

c) a = b ≠ c, α = β = γ = 90 o

d) a = b = c, α ≠ β = ϒ = 90 o

Answer: a

Explanation: Simple cubic have all sides equal and all angles equal. For reference, table of 7 Bravais lattices are tabulated below:

S.No. Crystal System Conventional Unit Cell Axis System

Lengths Angles

1 Cubic a = b = c α = β = γ = 90 o

2 Tetragonal a = b ≠ c α = β = γ = 90 o

3 Orthorhombic a ≠ b ≠ c α = β = γ = 90 o

4 Rhombohedral a = b = c α = β = γ ≠ 90 o

5 Hexagonal a = b ≠ c α = β = 90 o , γ = 120 o

6 Monoclinic a ≠ b ≠ c α = γ = 90 o ≠ β

7 Triclinic a ≠ b ≠ c α ≠ β ≠ γ ≠ 90 o

*Note—Order trick: C-T-O-R-H-M-T 

7. Which of the following axis system is being satisfied by tetragonal crystal system?

a) a = b = c, α = β = ϒ = 90 o

b) a ≠ b ≠ c, α = β = ϒ = 90 o

c) a = b ≠ c, α = β = ϒ = 90 o

d) a = b = c, α ≠ β = ϒ = 90 o

Answer: c

Explanation: Tetragon has two sides equal and all angles equal.

8. Which of the following axis system is being satisfied by orthorhombic crystal system?

a) a = b = c, α = β = γ = 90 o

b) a ≠ b ≠ c, α = β = γ = 90 o

c) a = b ≠ c, α = β = γ = 90 o

d) a = b = c, α ≠ β = γ = 90 o

Answer: b

Explanation: Orthorhombic have all sides unequal and all angles equal to a degree.

9. Which of the following axis system is being satisfied by rhombohedral  crystal system?

a) a = b = c, α = β = γ = 90 o

b) a ≠ b = c, α = β = γ = 90 o

c) a = b ≠ c, α = β = γ = 90 o

d) a = b = c, α = β = γ ≠ 90 o

Answer: d

Explanation: Rhombohedra have all sides equal and all angles equal but not 90 o .

10. Which of the following axis system is being satisfied by hexagonal crystal system?

a) a = b ≠ c, α = β = 90 o , ϒ = 120 o

b) a ≠ b = c, α = β = ϒ = 90 o

c) a = b ≠ c, α = β = ϒ = 90 o

d) a = b = c, α ≠ β = ϒ = 90 o

Answer: a

Explanation: Hexagonal have two sides equal and two angles equal to 90 o and one angle equal to 120 o .

11. Which of the following axis system is being satisfied by monoclinic crystal system?

a) a = b = c, α = β = 90 o ≠ ϒ

b) a ≠ b = c, α = β = ϒ = 90 o

c) a ≠ b ≠ c, α = β = 90 o ≠ ϒ

d) a = b = c, α ≠ β = ϒ = 90 o

Answer: c

Explanation: Monoclinic have all sides unequal and two angles equal to 90 o .

12. Which of the following axis system is being satisfied by triclinic crystal system?

a) a = b = c, α = β = ϒ = 90 o

b) a ≠ b = c, α = β = ϒ = 90 o

c) a ≠ b ≠ c, α ≠ β ≠ ϒ ≠ 90 o

d) a = b = c, α ≠ β = ϒ = 90 o

Answer: c

Explanation: Triclinic structures have all sides unequal and all angles are also unequal.

13. Which one of the following is most symmetrical?

a) Simple cubic cell

b) Hexagonal

c) Triclinic

d) Tetragonal

Answer: a

Explanation: In triclinic crystal system, we observe all the sides and angle to equal to each other (a = b = c and α = β = γ = 90 o ), thus giving highest symmetry  among all 7 Bravais Lattices.

14. Which one of the following is least symmetrical?

a) Tetragonal

b) Simple cubic

c) Triclinic

d) Monoclinic

Answer: c

Explanation: In triclinic crystal system, we observe all the sides and angle to unequal to each other (a ≠ b ≠ c and α ≠ β ≠ γ ≠ 90 o ), thus giving least symmetry  among all 7 Bravais Lattices.

This set of Manufacturing Engineering Interview Questions and Answers focuses on “Crystallography-2”.

1. What is the coordination number of a simple cubic  unit cell?

a) 4

b) 6

c) 8

d) 2

Answer: b

Explanation: There are six nearest neighbouring atoms for every atom in a simple cubic  unit cell, in other words, every atom in a SC unit cell is surrounded by 6 other atoms, thus coordination number of SC unit cell is is 6.

2. What is the coordination number of a face centered cubic  unit cell?

a) 4

b) 6

c) 8

d) 12

Answer: d

Explanation: In an FCC structure, there are eight atoms, one atom each at the corner of the unit cell and one atom at the centre of each face. For any corner atom of the unit cell, the nearest atoms are face-centred atoms. Thus, the coordination number for an FCC structure = 4 centre atoms below the horizonal plane + 4 centre atoms above the horizontal plane + 4 centre atoms on the horizonal plane.

Hence, the coordination number for an FCC structure is 4 + 4 + 4 = 12.

3. What is the coordination number of body centered cubic unit cell?

a) 4

b) 6

c) 8

d) 2

Answer: c

Explanation: For any corner atom of the BCC unit cell, the nearest atoms are the body centred atoms. There are eight-unit cells in neighbours with body-centered atoms. Hence, the coordination number for a BCC cubic unit cell is 8.

4. Effective number of atoms in a simple cubic  unit cell is equal to _________

a) 4

b) 1

c) 8

d) 2

Answer: b

Explanation: Total number of atoms at corners = 8 and each corner atom is shared by total 8-unit cells. Thus, effective number of atoms in an SC unit cell: 8 × 8⁄8 = 1.

5. Effective number of atoms in a face centered cubic  unit cell is equal to ________

a) 4

b) 1

c) 8

d) 2

Answer: a

Explanation: In an FCC unit cell, there are eight atoms: one at each corner of the cube and six face centered atoms of the six planes of the cube. As corner atoms are shared by eight adjacent cubes and the face centered atoms by two adjacent unit cells, total effective number of atoms in an FCC unit cell will be 4.

6. Effective number of atoms in a body centered cubic  unit cell is equal to _____________

a) 4

b) 6

c) 1

d) 2

Answer: d

Explanation: The unit cell of a cube contains eight atoms at the corners, which are shared by the eight adjoining cubes and one atom at the centre of the cube.

8 atoms at the corner: (8× 1 ⁄ 8 ) = 1 atom + 1 centre atom in the unit cell, So, there are “2” effective number of atoms in a BCC unit cell.

7. The atomic packing fraction in a simple cubic unit cell is ________

a) 0.74

b) 0.52

c) 0.68

d) 0.66

Answer: b

Explanation: a=r and APF = .

8. The atomic packing fraction in a body centered cubic unit is cell is ________

a) 0.74

b) 0.52

c) 0.68

d) 0.66

Answer: c

Explanation: r=/4×a and APF = .

9. If the radius of a copper atom is given as 1.27 A o , its density (in kg/m 3 ) will be?

a) 100.01

b) 86.25

c) 8979

d) 7968

Answer: c

Explanation: Formula to calculate the density of a cubic metal:

ρ (kg/m 3 ) = \(\frac{n × A.W}{a^3}\) × 1.66 × 10 -27

[where, ρ = density of metal, n = effective number of atoms per unit cell, A.W = Atomic weight of the metal in amu and a = lattice parameter in meter] Given: radius of copper = 1.27 A o = 1.27×10 -10 m

We know that atomic weight of copper = 63.5 amu

Lattice parameter to atomic radius relation for cubic structures are as follows:

Crystal Structure Effective Number of Atoms per Unit Cell Effective Number of Atoms per Unit Cell

Simple Cubic a = 2r 1

Body Centered Cubic a = 4r/√3 2

Face Centered Cubic a = 4r/√2 4

Hexagonal Close Packed Cubic a = 2r 6

We know that copper has FCC crystal structure, so it has ‘4’ effective number of atoms per unit cell and given its atomic radius = 1.27×10 -10 m

Therefore, lattice parameter of copper  = (4×1.27×10 -10 )/√2 = 3.59×10 -10 m

Therefore, density of copper = \(\frac{4 × 63.5}{^3}\) × 1.66 × 10 -27 ≈ 8979 kg/m 3 .

10. The atomic packing fraction in a face centered cubic unit is?

a) 0.74

b) 0.52

c) 0.68

d) 0.66

Answer: a

Explanation: a=2√2×r and APF = .

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Miller Indices”.

1. Stacking sequence in hexagonal close packed  structure is?

a) AAAAA

b) ABABAB

c) ABCABC

d) AABBAA

Answer: b

Explanation: The geometry of close packed hexagonal unit cell can be understood from the below figure, which indicates a plane view of atoms.

Figure: Stacking sequences of close packed layers of atoms. A-first layer ; B-second layer.

A is the first layer  and B is the second layer . In hexagonal close packed unit cell, the third layer of atoms go directly above the A layer, the fourth layer over the B layer, and so on; the sequence becomes ABABAB.

2. Stacking sequence in face centered cubic  close packed structure is?

a) AAAAA

b) ABABAB

c) ABCABC

d) AABBAA

Answer: c

Explanation: The stacking sequence in FCC can be best understood from the below figure.

Figure: Stacking sequences of close packed layers of atoms. A-first layer ; B-second layer; C-third layer.

A is the first layer  and B is the second layer . The third layer of atoms goes above the interstices marked C and the sequence only repeats at the fourth layer, which goes directly above the first layer. Thus, the stacking sequence is now ABCABC.

3. For pane  of FCC having a lattice parameter ‘a’, planar atomic density is given by?

a) 2.31/a 2

b) 2.31/a 3

c) 1.31/a 2

d) 1.31/a 3

Answer: a

Explanation: Upon visualizing  plane of FCC, one can identify that there the equilibrium triangle  of FCC consists 2 atoms ( 1 ⁄ 6 ×3 + 1 ⁄ 2 ×3=2). Also, the area of the equilibrium triangle  is 0.886 a 2 .

Therefore, the number of atoms per square inch which is nothing but its planar density = \(\frac{2}{0.866 a^2} = \frac{2.31}{a^2}\).

4. For pane  of BCC having a lattice parameter ‘a’, planar atomic density is given by?

a) 1.07/a 2

b) 0.58/a 2

c) 2.07/a 2

d) 0.78/a 2

Answer: b

Explanation: From the geometry of the triangle , it is clear that it has 0.5 atoms in it  and the area of the triangle  is 0.866 a 2 .

Therefore, the number of atoms per square inch which is nothing but its planar density = \(\frac{0.5}{0.866 a^2} = \frac{0.58}{a^2}\).

5. For pane  of BCC having a lattice parameter ‘a’, planar atomic density is given by?

a) 1/a 3

b) 2/a 2

c) 3/a 4

d) 1/a 2

Answer: d

Explanation: The atomic arrangement on square  of BCC indicates that it has 1 atom and area of this square  is a 2 . Thus, its planar density = 1/a 2 .

6. For pane  of BCC having a lattice parameter ‘a’, planar atomic density is given by?

a) 3.690/a 2

b) 2.312/a 2

c) 1.414/a 2

d) 0.580/a 2

Answer: c

Explanation: From the geometry of the rectangle , it is clear that it has 2 atoms in it ( 1 ⁄ 4 ×4+1=2) and the area of the rectangle  is 0.866 a 2 .

Therefore, the number of atoms per square inch which is nothing but its planar density = \(\frac{2}{1.414 a^2} = \frac{1.414}{a^2}\).

7. For pane  of SC having a lattice parameter ‘a’, planar atomic density is given by?

a) 0.508/a 2

b) 0.707/a 2

c) 0.707/a 3

d) 0.508/a 3

Answer: b

Explanation: The atomic arrangement on  plane in simple cubic  unit cell indicates that it has 1 atom ( 1 ⁄ 4 ×4=1) in this plane having an area = \(\sqrt{2} a^2\).

Therefore, the number of atoms per square inch which is nothing but its planar density = \(\frac{1}{1.414 a^2} = \frac{0.707}{a^2}\).

8. For pane  of SC having a lattice parameter ‘a’, planar atomic density is given by?

a) 0.58/a 2

b) 0.78/a 3

c) 0.68/a 2

d) 0.88/a 2

Answer: a

Explanation: The atomic arrangement on triangle  in simple cubic  unit cell indicates that it has 0.5 atoms ( 1 ⁄ 6 ×3=0.5) in this plane having an area = 0.866 a 2 .

Therefore, the number of atoms per square inch which is nothing but its planar density = \(\frac{0.5}{0.866 a^2} = \frac{0.577}{a^2}\).

9. Which of the following equation describes Bragg’s law of diffraction? 

a) 2d sinθ = λ

b) 2d = nλ

c) 2d = nλ sinθ

d) 2d sinθ = nλ

Answer: d

Explanation: Bragg’s law, which describes the constructive interference conditions for θ to be at its strongest: nλ = 2d sinθ, where λ is the wavelength of the incident wave and and n is the order of diffraction which is always a positive integer and d is the interplanar spacing and θ = angle of diffraction. This equation can be easily derived upon constructing a basic wave reflection diagram taking incident angle as θ.

10. Powder X-ray technique can be used to determine crystal structures.

a) True

b) False

Answer: a

Explanation: The powder method is used to determine the values of lattice parameters accurately. As we know, lattice parameters defines the axis system, which in turns can predict the crystal structure of the powder sampled.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Imperfection and Defects In Solid”.

1. Vacancy defects in solids is a sub type of __________

a) Point imperfections

b) Line imperfections

c) Volume imperfections

d) Surface imperfections

Answer: a

Explanation: The simplest of the point defects is a vacancy, vacant lattice site. This could occur an atom is being missing from its lattice site. All crystalline solids contains vacancies, in fact, it is impossible for a material to be free of these vacancies, making them to call equilibrium defects. For reference, all the imperfections in solids are being tabulated below:

IMPERFECTIONS IN SOLIDS

Point Imperfections Line Imperfections Surface Imperfections Volume Imperfections

Vacancies Dislocations Surface Voids

Interstitial Impurities Disclinations Grain boundaries Cracks

Substitutional Impurities Twin boundaries Inclusions

Schottky defect Stacking faults Precipitates

Frenkel defect Interphase boundary Twins

2. Substitution of a foreign atom in the site of parent atom in the crystal is a?

a) Vacancy defect

b) Substitution impurity

c) Volume imperfection

d) Vacancy defect

Answer: b

Explanation: When an impurity atom of equal to atomic size of the host atom is being replaced or substituted for the host atoms, is called substitutional impurity.

3. Edge dislocation imperfection is a sub type of _____________

a) Point imperfections

b) Line imperfections

c) Volume imperfections

d) Surface imperfections

Answer: b

Explanation: A dislocation is a one-dimensional or linear defect around which some of the atoms are misaligned. Edge dislocation is a type of dislocation, where an extra portion of plane of atoms, the edge terminates within the crystal.

4. Displacement of an ion from regular location to interstitial location is known as ____________

a) Vacancy defect

b) Line imperfection

c) Schottky’s defect

d) Frenkel defect

Answer: d

Explanation: Frenkel defect, named after its discoverer “Yakov Frenkel”, forms when an atom leaves its regular position thus creating a vacancy there, and becomes interstitial by positioning itself into nearby interstitial location. Usually small ion  undergoes this phenomenon.

5. When a pair of cation and anion are missing in a crystal, it is called ____________

a) Vacancy defect

b) Line imperfection

c) Schottky’s defect

d) Frenkel defect

Answer: c

Explanation: Schottky’s defect, named after its discoverer “Walter H. Schottky”, forms when two atoms of opposite charge  leaves their regular atomic positions thus creating two vacancies. As two atoms of opposite charges are leaving, there is no change in overall charge of the material with Schottky’s defect. Schottky’s defect is known for its presence in ionic crystals.

6. Which one of the following is not a zero-dimensional defect?

a) Vacancy defect

b) Substitution imperfection

c) Schottky’s defect

d) Screw dislocation

Answer: d

Explanation: Screw dislocation is a type of dislocations  which thought to be formed by a shear stress that is applied to produce the distortion in a spiral manner inside the crystal, indicating burgers vector parallel to this dislocation type.

7. Twin or Twinning is a category of ________

a) Point imperfections

b) Line imperfections

c) Volume imperfections

d) Surface imperfections

Answer: c

Explanation: A twin boundary is a two-dimensional imperfection , but the entire twin is a category of volume imperfections.

8. As the grain size of a metal increases, its strength ________

a) Decreases

b) Increases

c) Remains constant

d) No effect of grain size on strength

Answer: a

Explanation: Strength of a metal is directly proportional to its ability resist plastic deformation, thus resisting its dislocation movement. As one can relate that, more the number of grain boundaries , more is the obstruction to the movement of dislocation, thus more is the strength of a metal. So, if grain size increases, its strength decreases. This phenomenon can be best understood with the help of Hall-Petch relation.

9. As the grain size of a meal increases, its ductility ________

a) Decreases

b) Increases

c) Remains constant

d) No effect of grain size on ductility

Answer: a

Explanation: Fine the grain size , more is the number of grain boundaries, thus more is the yield strength, thus more is the ductility. So, if grain size increases, its ductility decreases.

10. Phenomenon of cross slip occurs in ________

a) Point imperfections

b) Line imperfections

c) Volume imperfections

d) Surface imperfections

Answer: b

Explanation: When we apply a stress, it causes screw dislocations to move from one slip plane to another slip plane, which is known as its cross slip. Cross slip is one of the primary mechanisms that causes plastic deformation in metals.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Mechanical Properties”.

1. Resistance of a material against any external force is termed as _______________

a) Stiffness

b) Malleability

c) Strength

d) Hardness

Answer: c

Explanation: Strength is that mechanical property of a material by virtue of which it resists change in its dimension shape and any failure by application of any external force.

2. The property of a material to resist any elastic deformation is termed as ____________

a) Stiffness

b) Hardness

c) Malleability

d) Strength

Answer: a

Explanation: The ability of a material or shape to resist elastic deflection is termed as stiffness of that material.

3. Resistance developed by surface of any material is known as ____________

a) Strength

b) Hardness

c) Stiffness

d) Creep

Answer: b

Explanation: Hardness is a surface property. Resistance developed by surface of any material is known as hardness.

4. Permanent deformation of material with respect to time due to constant load and variable temperature is termed as ____________

a) Elasticity

b) Isotropy

c) Hardness

d) Creep

Answer: d

Explanation: Creep is time and temperature dependent phenomenon. With the passage of time and other environmental condition, material may lead to fracture point.

5. Material having same identical values a property in all directions can be termed as ____________

a) Creep

b) Anisotropy

c) Isotropy

d) Orthotropic

Answer: c

Explanation: Isotropic materials have the same property in all directions. Crystalline substance is isotropic in nature.

6. Property by virtue of which material can absorb strain energy without plastic deformation is called ____________

a) Creep

b) Anisotropy

c) Resilience

d) Fatigue

Answer: c

Explanation: Resilience is the strain energy absorbed of a material without undergoing a plastic deformation.

7. Which of the following hardness test uses steel ball as indenter?

a) Brinell hardness test

b) Rockwell C hardness test

c) Vickers hardness test

d) Rockwell B hardness test

Answer: a

Explanation: Steel ball is used as indentor in Brinell hardness test.

8. In which of the following test specimen is in the form of the simply supported beam?

a) Izod test

b) Rockwell hardness test

c) Charpy test

d) Brinell test

Answer: c

Explanation: In the Charpy test a supported beam specimen is used.

9. In which of the following test specimen is in the form of cantilever beam?

a) Izod test

b) Rockwell hardness test

c) Charpy test

d) Brinell test

Answer: a

Explanation: Izod test is like Charpy test, but the Izod geometry consists of a cantilever beam with the notch located on the same side as the impact point.

10. The total number of scales used in Rockwell hardness test is?

a) 12

b) 14

c) 15

d) 16

Answer: c

Explanation: There are 15 scales used in Rockwell hardness test, which are being differentiated based on indenter used and the material sampled.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Mechanical Testing”.

1. Hounsfield tensometer can be used to perform __________

a) Tensile test

b) Compressive test

c) Hardness test

d) Toughness test

Answer: a

Explanation: Hounsfield tensometer, Universal testing machine, Instron and MTS  are the common machine that are used to for tensile test. Hounsfield tensometer is a small machine and widely used for tensile test in research laboratories.

2. ASTM stands for __________

a) American Society for Tensile Measurement

b) American Society for Testing and Materials

c) American Society for Tool Measurement

d) American Society for Tensile Material

Answer: b

Explanation: ASTM stands for American Society for Testing and Materials. ASTM develops technical standards for a wide range of materials products. American Society for Tensile Measurement are used to decide various standard in tensile measurement.

3. According to ASTM standard, which of the following relation is correct about gauge length of cross section area ‘A’?

a) L = 2.51\ L = 4.51\ L = 2\ L = 3.51\(\sqrt{A}\)

Answer: b

Explanation: According to ASTM standard, gauge length = 4.51\(\sqrt{A}\).

4. According to BS standard, which of the following relation is correct about gauge length of cross section area ‘A’?

a) L = 2.51\ L = 4.51\ L = 4\ L = 3.51\(\sqrt{A}\)

Answer: c

Explanation: According to BS standard, gauge length = 4\(\sqrt{A}\), where A denotes the cross section area of specimen used under testing.

5. According to DIN standard, which of the following relation is correct about gauge length of cross section area ‘A’?

a) L = 12.51\ L = 14.51\ L = 4\ L = 11.2\(\sqrt{A}\)

Answer: d

Explanation: According to DIN standard, gauge length=11.2\(\sqrt{A}\), where A denotes the cross section area of specimen used under testing.

6. Mohs hardness test has a scale range of _________

a) 1 to 10

b) 100 to 200

c) 1 to 1000

d) 1 to 3000

Answer: a

Explanation: Mohs hardness scale was developed by “Frederich Mohs” in 1822, which is a chart that denotes relative hardness of the various materials . According to Mohs scale, diamond is the hardest material and talc is the softest material.

7. Brinell hardness test has a scale range of _________

a) 0 to 10

b) 100 to 200

c) 0 to 1000

d) 0 to 3000

Answer: d

Explanation: Brinell hardness test has a scale range of 0 to 3000. Brinell hardness number of soft irons is ranges from 67 to 500.

8. Rockwell hardness test has a scale range of _________

a) 0 to 10

b) 100 to 200

c) 0 to 1000

d) 0 to 3000

Answer: c

Explanation: Rockwell hardness test has a scale range of 0 to 1000. It is used to measure the hardness of a specimen.

9. Vickers hardness test has a scale range of _____________

a) 0 to 10

b) 100 to 200

c) 0 to 1000

d) 0 to 3000

Answer: d

Explanation: Vickers hardness test has a scale range of 0 to 3000. It is used to measure the hardness of a specimen.

10. Brinell Hardness Number  for soft iron is between _____________

a) 1000-2000

b) 227-857

c) 67-500

d) 0-10

Answer: c

Explanation: Brinell hardness number  of soft iron ranges from 67 to 500.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Non-Destructive Testing”.

1. What is first step involved in the process of preparing test sample for microstructural examination?

a) Rough polishing

b) Fine grinding

c) Fine polishing

d) Etching

Answer: b

Explanation: Fine grinding involves the use of abrasive silicon carbide, to get a flat surface, that is nearly free of the disturbed or deformed scratches which were introduced in the previous sample preparation step. For reference, the sample preparation steps are depicted in the below schematic:

2. Which of the following compound is used for fine polishing?

a) Aluminum oxide

b) Nitric oxide

c) Silicon carbide

d) Iron oxide

Answer: a

Explanation: Powder form of aluminum oxide is used for fine polishing process. It is surface treatment process.

3. Etching of specimen is done to achieve ___________

a) Visible grain boundary

b) Invisible grain boundary

c) Toughness

d) Hardness

Answer: a

Explanation: Etching is done to obtain visible grain boundary. It is a surface treatment process.

4. What is the average grain diameter  for the grain size ASTM grain size 12?

a) .0066

b) .0078

c) .0021

d) .0056

Answer: d

Explanation: According to ASTM standard E1112, ”standard test methods for determining average grain size”:

n = 2 G-1 , where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X. Upon calculations one can deduce that:

Average Grain diameter  = \(\frac{1}{\sqrt{\frac{n×10^4}{645}}}\)

Given ASTM grain size 12, thus, n = 2 12-1 = 2 11 = 2048

Therefore, average grain diameter = \(\frac{1}{\sqrt{\frac{2048×10^4}{645}}}\) = 0.0056 mm.

5. Equipment used for inspection of inside portion of hollow chamber or narrow tube is known as ___________

a) Endoscope

b) Telescope

c) Borescope

d) Flexiscope

Answer: c

Explanation: Borescope is used for visual of inside portion of the hollow chamber.

6. What is the value of average number of grains in per square inch for ASTM 11?

a) 2048

b) 1024

c) 6

d) 5

Answer: b

Explanation: According to ASTM standard E1112, ”standard test methods for determining average grain size”:

n = 2 G-1 , where ‘G’ is the grain size number and ‘n’ represents the average number of grains per square inch at a magnification of 100X.

Given ASTM grain size 12, thus, n = 2 11-1 = 2 10 = 1024.

7. Which of the following property will be more in fine grained structure?

a) Ductility

b) Corrosion resistance

c) Creep resistance

d) Hardness

Answer: a

Explanation: Finer the grain size , more is the number of grain boundaries, thus more is the yield strength, thus more is the ductility. This is the reason why we can easily draw a fine-grained structure into wires.

8. Which of the following property will be more in coarse grain structure?

a) Ductility

b) Corrosion resistance

c) Hardness

d) Toughness

Answer: a

Explanation: Grain boundaries are susceptible to corrosion. Coarse grain structure has less grain boundaries, thus has greater corrosion resistance.

9. Which of the following penetrating liquid is used in a liquid penetration test?

a) Water

b) Chlorine based solvent

c) Petroleum based carrier fluid

d) Fluorine based solvent

Answer: c

Explanation: In liquid penetration test, either petroleum-or-water based carrier fluids are used as solvents or cleaners according to the type of penetrant used. Petroleum based carrier fluid is used as penetrating liquid in liquid penetration test along with fluorescent red colour dye for visible light.

10. Which of the following non destructive testing is used to detect change in composition of any material?

a) Liquid penetration test

b) Ultrasonic test

c) Eddy current test

d) Radiography

Answer: d

Explanation: Radiography enables us to detect the change in composition. X-rays or γ-rays are used in radiography technique.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Iron Carbon Phase Diagram-1”.

1. The melting point of iron (in o C) is?

a) 768

b) 1535

c) 1410

d) 910

Answer: b

Explanation: Melting point of iron in degree centigrade is 1535 o C.

2. Iron-Carbon phase diagram is a ___________

a) Unary phase diagram

b) Binary phase diagram

c) Tertiary phase diagram

d) Ternary phase diagram

Answer: b

Explanation: Binary phase diagrams are based on two component systems. Here, the two components may be mixed in an infinite number of different proportions, which indicates that composition also becomes a variable, along with pressure and temperature. Iron-carbon phase diagram, Pb-Sn diagram are the best examples of this category.

3. The temperature (in o C) of peritectic reaction in iron-carbon phase diagram is?

a) 1539

b) 1493

c) 910

d) 1175

Answer: b

Explanation: The invariant peritectic reaction  in Fe-C phase diagram is given by:

L  + δ-ferrite  \

 

4. The temperature (in o C) of eutectic reaction in iron-carbon phase diagram is?

a) 1539

b) 1493

c) 910

d) 1150

Answer: d

Explanation: The invariant eutectic reaction  in Fe-C phase diagram is given by:

L  \

 

 + Cementite 

5. The temperature (in o C) of eutectoid reaction in iron-carbon phase diagram is?

a) 1120

b) 725

c) 910

d) 820

Answer: b

Explanation: The invariant peritectoid reaction  in Fe-C phase diagram is given by

γ  \

 

+ Cementite .

6. The percentage of carbon at eutectic point in Fe-C phase diagram is?

a) 2.1

b) 4.3

c) 0.83

d) 0.02

Answer: b

Explanation: The lowest melting alloy, the Fe-4.3% C alloy is called eutectic cast iron. This is a single-phase liquid  of 4.3% carbon at the eutectic temeprature 1150 o C.

7. The percentage of carbon at eutectoid point in Fe-C phase diagram is?

a) 2.1

b) 4.3

c) 0.83

d) 0.02

Answer: c

Explanation: During cooling, austenite of 0.77% C, at a temeprature 725 o C undergoes eutectoid transformation and forms a eutectoid a mixture of ferrite and cementite, known as pearlite.

8. The percentage of carbon at peritectic point in Fe-C phase diagram is?

a) 2.1

b) 4.3

c) 0.83

d) 0.18

Answer: d

Explanation: Percentage of carbon at peritectic point = 0.18%. Peritectic reaction in iron-carbon phase diagram takes place at constant temperature of 1493 o C.

9. Which of the following reaction does not exhibit mushy zone in Fe-C phase diagram?

a) Eutectic reaction

b) Peritectic reaction

c) Eutectoid reaction

d) Peritectoid reaction

Answer: a

Explanation: A mushy zone is nothing but a solid-liquid mix in a two-phase region. The alloys or reactions, which exhibits lower melting points than the two pure metals are known as eutectic alloy systems taking eutectic reaction does not exhibit mushy zone.

10. γ form of iron is?

a) Magnetic

b) Non magnetic

c) Occurs below 768 o C

d) Occurs above 1410 o C

Answer: a

Explanation: γ form of iron is known as austenite , which is an interstitial solid solution of carbon in FCC iron. Austenite is soft, ductile, tough, malleable and non-magnetic.

This set of Manufacturing Engineering Questions & Answers for freshers focuses on “Iron Carbon Phase Diagram”.

1. Which of the following material has the carbon varying from 2.1 to 4.3%?

a) Dead steel

b) Mild steel

c) Medium carbon steel

d) Cast iron

Answer: d

Explanation: Cast irons are the alloy of iron and carbon that contains 2.1 to 4.3% C, along with other varying amounts of silicon and manganese. This varying carbon range makes them easily castable, asking them to call cast irons.

2. Which of the following material has the carbon varying from 4.3 to 6.67%?

a) Pig iron

b) Mild steel

c) Medium carbon steel

d) Cast iron

Answer: a

Explanation: Pig iron contains a very high carbon content, usually varies from 4.3 to 6.67%. The pig iron is called so, as it resembles the shape of a reclining pig.

3. The eutectoid mixture of α+Fe 3 C is known as ______________

a) Ferrite

b) Pearlite

c) Cementite

d) Austenite

Answer: b

Explanation: The eutectoid mixture of ferrite  and cementite (Fe 3 C) as alternate lamellae is known as pearlite. Pearlite is called so, as it lustres like pearl.

4. The BCC structure of Fe-C solid solution is known as ______________

a) Ferrite

b) Cementite

c) Pearlite

d) Austenite

Answer: a

Explanation: Ferrite is an interstitial solid solution of carbon in alpha iron . It derives its name from Latin word “ferrum” meaning iron.

5. The FCC structure of Fe-C solid solution is known as __________

a) Ferrite

b) Cementite

c) Pearlite

d) Austenite

Answer: d

Explanation: Austenite is an interstitial solid solution of carbon in γ and has FCC structure.

6. Which of the following is soft in nature?

a) Coarse pearliite

b) Fine pearlite

c) Bainite

d) Martensite

Answer: a

Explanation: Coarse pearlite forms upon annealing which makes them to posses greater interlamellar spaced ferrite and cementite, when compared with, fine pearlite which forms upon normalizing a eutectoid steel. The more interlamellar spacing makes coarse pearlite to have soft nature.

7. Which of the following is hardest in nature?

a) Coarse pearliite

b) Fine pearlite

c) Bainite

d) Martensite

Answer: d

Explanation: Martensite is the hardest phase that can be produced by quenching a steel. Its BHN is about 700. The high rate of strain hardening and dispersion strengthening mechanisms makes the martensite hardest among steel phases. Its hardness can be varied directly with varying percentage of carbon in steel.

8. Which of the following iron carbon mixture, is the product of furnace cooling?

a) Coarse pearliite

b) Fine pearlite

c) Bainite

d) Martensite

Answer: a

Explanation: Coarse pearlite is obtained when steel is slowly cooled in a furnace atmosphere, and this complete process is termed as annealing.

9. Which of the following iron carbon mixture, is the product of water cooling?

a) Coarse pearliite

b) Fine pearlite

c) Bainite

d) Martensite

Answer: d

Explanation: The body centered tetragonal  martensite is formed upon quenching a steel. Usually the quenching mediums are water, oil and brine, etc.

10. Which of the following iron carbon mixture, is the product of air cooling?

a) Coarse pearliite

b) Fine pearlite

c) Bainite

d) Martensite

Answer: b

Explanation: Fine pearlite is obtained when steel is slowly cooled in air, and this complete process is termed as normalizing.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Phase Diagram”.

1. Which of the following equation represents the Gibbs phase rule?

a) F = C + P + 2

b) F = C – P + 2

c) F = C + P + 1

d) F = C + P – 1

Answer: b

Explanation: The Gibbs phase rule is represented as: F = C – P + 2, where F = number of intensive degrees of freedom, P = number of phases and C = minimum number of independent constituents.

2. Number of degrees of freedom at a triple point in unary phase diagram is?

a) 1

b) 10

c) 0

d) -1

Answer: c

Explanation: A unary phase diagram has a single component thus, at triple point, the number of degrees of freedom, according to Gibbs phase rule F = 1 – 3 + 2 = 0.

3. The invariant reaction involving, a liquid phase decomposing into two different solids on cooling is known as _________

a) Eutectoid point

b) Eutectic point

c) Peritectic point

d) Peritectoid point

Answer: b

Explanation: The eutectic invariant reaction in general can be represented as:

L \(_{\overrightarrow{Cooling}}\) S 1 + S 2

where, L represent the liquid of eutectic composition and S 1 and S 2 are two different solids of fixed composition each.

4. The invariant reaction involving a solid phase decomposing into two different solids on cooling is known as ____________

a) Eutectoid point

b) Eutectic point

c) Peritectic point

d) Peritectoid point

Answer: a

Explanation: The eutectoid invariant reaction is a solid-state version of the eutectic reaction and in general, can be represented by an equation:

S 1 \(_{\overrightarrow{Cooling}}\) S 2 + S 3

where, S 1 , S 2 and S 3 are three different solids each of fixed composition.

5. The invariant reaction involving a liquid phase and a solid phase changing into a single solid phase on cooling is known as ____________

a) Eutectoid point

b) Eutectic point

c) Peritectic point

d) Peritectoid point

Answer: c

Explanation: A peritectic reaction in general can be represented by an equation:

L + S 1 \(_{\overrightarrow{Cooling}}\) S 2

where, L represents a liquid of fixed composition, S 1 and S 2 are two different solids of fixed composition each.

6. The invariant reaction involving two solid phases changing into a single solid phase on cooling is known as ___________

a) Eutectoid point

b) Eutectic point

c) Peritectic point

d) Peritectoid point

Answer: d

Explanation: The peritectoid invariant reaction is a solid-state version of the peritectic reaction and in general, can be represented by an equation:

S 1 + S 2 \(_{\overrightarrow{Cooling}}\) S 3

where, S 1 , S 2 and S 3 are three different solids each of fixed composition.

7. For binary phase diagram Gibbs phase rule may be given as ____________

a) F = C + P + 2

b) F = C – P + 2

c) F = C – P + 1

d) F = C + P – 1

Answer: c

Explanation: Binary phase diagrams has two components. Apart from temperature and pressure, we will be having one composition variable for each of the phases in equilibrium. In order to simplify the Gibbs phase rule on paper , binary phase diagrams are usually drawn at atmospheric pressure, showing variations in temperature and composition only. Pressure changes often produce no significant effect on the equilibrium and, therefore, it is customary to ignore the pressure variable and the vapour phase. The modified condensed rule is represented as:

F = C – P + 1

8. The Line joining a liquid phase with liquid and solid phase mixture is known as ____________

a) Liquidus

b) Solidus

c) Tie line

d) Solvus

Answer: a

Explanation: Liquidus is the line joining liquid phase with liquid and solid phase mixture.

9. The line joining a solid phase with liquid and solid phase mixture is known as _____________

a) Liquidus

b) Solidus

c) Tie line

d) Solvus

Answer: b

Explanation: Solidus is the line joining liquid phase with liquid and solid phase mixture.

10. Melting point of copper (in o C) is?

a) 985

b) 1085

c) 1453

d) 1200

Answer: b

Explanation: The copper has a melting point of 1085 o C.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Ferrous Metal”.

1. Pig iron is a product of ____________

a) Cupola

b) Bessemer converter

c) Open hearth furnace

d) Blast furnace

Answer: d

Explanation: Blast furnace when smelted iron ore in it, produces pig iron. Pig iron has a carbon content, typically 3.5-4.5%, which makes it brittle, thus of less industrial use.

2. Cast iron is a product of ___________

a) Cupola

b) Bessemer converter

c) Open hearth furnace

d) Blast furnace

Answer: a

Explanation: The cupola furnace  can be used to melt cast irons, bronzes, etc. Cast irons have a carbon content of 2-4%, and have low melting temperatures, which makes them easily castable.

3. Wrought iron is a product of ___________

a) Cupola

b) Bessemer converter

c) Puddling furnace

d) Blast furnace

Answer: c

Explanation: The puddling furnace creates wrought iron  from the pig iron. The wrought iron is tougher and malleable.

4. Steel is a product of ___________

a) Cupola

b) Blast furnace

c) Puddling furnace

d) Bessemer converter

Answer: d

Explanation: The Bessemer converter was the first inexpensive furnace to make steel in olden days. The fundamental idea is, removal of impurities from iron and making steel by oxidizing. Open hearth furnace has taken over Bessemer process due to its nitrogen control in steel.

5. Red hardness of an alloy steel can be improved by adding ____________

a) Tungsten

b) Vanadium

c) Manganese

d) Titanium

Answer: a

Explanation: Red hardness means capability of material to retain hardness at high temperature. It can be achieved for steel when alloyed high high melting metals like, tungsten, molybdenum, vanadium and chromium, etc.

6. Abrasion resistance of an alloy steel can be improved by adding ___________

a) Tungsten

b) Vanadium

c) Manganese

d) Chromium

Answer: d

Explanation: Chromium is generally added to steel to increase corrosion resistance and oxidation, to increase hardenability, to improve high-temperature strength, and to improve abrasion resistance in high-carbon compositions. The formation of hexagonal Cr 7 C 3 is responsible for this abrasion resistance to steel.

7. Wear resistance of an alloy steel can be improved by adding ___________

a) Tungsten

b) Vanadium

c) Manganese

d) Titanium

Answer: c

Explanation: Manganese is normally present in all commercial steels. High levels of manganese presence produces an austenitic steel with improved wear and abrasion resistance.

8. Corrosion resistance of an alloy steel can be improved by adding ___________

a) Tungsten

b) Vanadium

c) Chromium

d) Titanium

Answer: c

Explanation: Chromium when added in the range 10.5%-18% in weight to steel, forms a passive oxide layer (Cr 2 O 3 ), thus transforming steel to a corrosion resistant steel .

9. Tensile strength of an alloy steel can be improved by adding ____________

a) Nickel

b) Vanadium

c) Manganese

d) Titanium

Answer: a

Explanation: Nickel can improve tensile strength as well as toughness of alloy steel. Small additions of niobium  also increases the tensile strength of carbon steel.

10. Which of the following induces fine grain distribution in alloy steel?

a) Nickel

b) Vanadium

c) Manganese

d) Titanium

Answer: b

Explanation: After Al, vanadium if by far the mostly used grain refiner in steel. It forms a microscopic precipitate particle in steel, which acts as pinning agents, thus obstruct the grain growth at higher temperatures, encouraging new grains to nucleate.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Non-Ferrous Metal”.

1. Alloy of copper and zinc is known as __________

a) Brass

b) Bronze

c) Duralumin

d) Nichrome

Answer: a

Explanation: Brass is a substitutional alloy of copper and zinc. It has many useful properties, such as low melting point, workability, electrical conductivity and thermal conductivity, corrosion resistance, etc.

2. Alloy of Ni and Fe is termed as ___________

a) Brass

b) Bronze

c) Duralumin

d) Invar

Answer: d

Explanation: Invar is an alloy of nickel and iron generically known as FeNi36. It has low thermal expansion coefficient.

3. Major constituent of the gun metal is ____________

a) Copper

b) Nickel

c) Iron

d) Zinc

Answer: a

Explanation: Gun metal  contains 83% Cu and 2% Zn and 10% Sn.

4. Major constituent of Muntz metal is _____________

a) Copper

b) Nickel

c) Iron

d) Zinc

Answer: a

Explanation: Mutz metal contains 60% Cu and 40% Zn. It is commonly used in architectural applications.

5. Major constituent of the Nichrome is _____________

a) Copper

b) Nickel

c) Iron

d) Zinc

Answer: b

Explanation: Nichrome contains 80% Ni and 20% Cr. Nichrome mostly used as a resistant wire and in dental fillings.

6. Major constituent of Constantan alloy is ____________

a) Copper

b) Nickel

c) Iron

d) Zinc

Answer: a

Explanation: Constantan  contains 60% Cu and 40% Ni. It finds its mainly in thermocouples and has strong negative seebeck coefficient above 0 o C.

7. Major constituent of Elektron alloy is ____________

a) Copper

b) Nickel

c) Magnesium

d) Zinc

Answer: c

Explanation: Elektron contains 3-12% aluminum and 2% zinc, 0.03% manganese and rest is magnesium. It is very light alloy and used where weight is the major consideration in design.

8. Which of the following alloy is widely used in thermo couples?

a) Brass

b) Bronze

c) Duralumin

d) Nichrome

Answer: d

Explanation: Nichrome contains 80% Ni and 20% Cr. It is used mostly in thermocouples and in strain gauges.

9. Major constituent of Duralumin alloy is ____________

a) Copper

b) Nickel

c) Iron

d) Aluminum

Answer: d

Explanation: Duralumin is the age hardenable alloy of aluminium alloyed mainly with copper and with manganese and magnesium. Being a lightweight alloy, duralumin finds its use widely in aerospace industry.

10. What is the approximate percentage of Lead in soft solder?

a) 60

b) 50

c) 90

d) 99.02

Answer: b

Explanation: Soft solder is the eutectic alloy of 50% Pb and 50% Sn, having a melting point of 450 o C.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Heat Treatment”.

1. Which of the following is the hardest constituent of steel?

a) Ledeburite

b) Austenite

c) Bainite

d) Martensite

Answer: d

Explanation: Martensite is the hardest constituent of steel. The primary reasons accounting for this could be, the internal strains within BCC iron due to the excess carbon presence and due to the plastic deformation of parent FCC iron  surrounding the martensitic plate. Rate of cooling and the amount of carbon percentage in steel are directly proportional to the amount of hardness achieved in martensitic transformation.

2. Iron possesses BCC crystal structure up to ?

a) 1539

b) 768

c) 910

d) 1410

Answer: b

Explanation: Pure iron possess either BCC or FCC crystal structure as its temperature is increased from room temperature to its melting point. At room temperature to 910 o C, it is having BCC, between 910 o C and 1410 o C it is having face centered cubic, and from 1410 o C to its melting point (1539 o C) it returns to its BCC crystal structure.

3. Iron possesses BCC crystal structure above ?

a) 1539

b) 768

c) 910

d) 1410

Answer: d

Explanation: From 1410 o C to its melting point (1539 o C) iron is having BCC crystal structure.

4. Iron possesses FCC crystal structure above ?

a) 1539

b) 768

c) 910

d) 1410

Answer: c

Explanation: Between 910 o C and 1410 o C iron is having face centered cubic crystal structure.

5. Which of the following form of iron is magnetic in nature?

a) α

b) δ

c) γ

d) λ

Answer: a

Explanation: The alpha form of iron is magnetic and stable at all temperatures below 910 o C.

6. For steel, which one of the following properties can be enhanced upon annealing?

a) Hardness

b) Toughness

c) Ductility

d) Resilience

Answer: c

Explanation: A furnace cooling technique, annealing will enhance the ductility of steel, due to the formation of coarse pearlite.

7. In Annealing, cooling is done in which of the following medium?

a) Air

b) Water

c) Oil

d) Furnace

Answer: d

Explanation: In annealing, after solutionising, material is used to furnace cool, means furnace is switched off and the steel sample inside is let cool down.

8. In normalizing, cooling is done in which of the following medium?

a) Air

b) Water

c) Oil

d) Furnace

Answer: a

Explanation: In normalizing, steel is heat treated above its critical temperature, solutionised, and then allowed to cool for a long time by keeping it in air. In steel, it forms fine pearlite, which imparts strength to steel.

9. Mild steel can be converted into high carbons steel by which of the following heat treatment process?

a) Annealing

b) Normalizing

c) Case hardening

d) Nitriding

Answer: c

Explanation: Case hardening, also referred as carburizing increases carbon content of steel, thus, imparting hardness to steel.

10. Upon annealing, eutectoid steel converts to which of the following?

a) Perlite

b) Cementite

c) Austenite

d) Martensite

Answer: a

Explanation: Eutectoid steels upon annealing produces pearlite . Pearlite is an alternate lamellae of ferrite and cementite.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Magnetic Properties of Material”.

1. Which of the following parameter is used to assess the magnetic ability of a material?

a) Magnetic flux density

b) Magnetization

c) Magnetic dipole moment

d) Susceptibility

Answer: d

Explanation: Magnetic susceptibility is a measure to quantify the ability of a material to undergo magnetization in an applied magnetic field. It is the ratio of magnetization  to the applied magnetic field intensity .

2. For a diamagnetic material, which of the following statement is correct?

a) Magnetic susceptibility < 0

b) Magnetic susceptibility > 0

c) Magnetic susceptibility = 0

d) Magnetic susceptibility = 1

Answer: a

Explanation: Diamagnetic materials are those which repel magnetic field and hence their magnetic susceptibility  is negative.

3. For a diamagnetic material, which of the following statement is correct (μ r = relative permeability)?

a) μ r > 2

b) μ r < 1

c) μ r > 1

d) μ r = 1

Answer: b

Explanation: A diamagnetic material has a constant relative permeability (μ r ) slightly less than 1.

4. For a paramagnetic material, which of the following statement is correct?

a) Magnetic susceptibility < 0

b) Magnetic susceptibility > 0

c) Magnetic susceptibility = 0

d) Magnetic susceptibility = -1

Answer: b

Explanation: Magnetic susceptibility  is very small positive quantity for a paramagnetic material.

5. For a paramagnetic material, which of the following statement is correct (μ r = relative permeability)?

a) μ r = 0

b) μ r < 1

c) μ r > 1

d) μ r < 0

Answer: c

Explanation: A paramagnetic material has a constant relative permeability  slightly greater than 1.

6. What is the curie temperature of iron ?

a) 2195 K

b) 495 K

c) 895 K

d) 1095 K

Answer: d

Explanation: The curie temperature of iron is about 1095K. It changes its magnetic behaviour from ferromagnetic to paramagnetic.

7. With an increase in temperature, magnetic susceptibility of a ferromagnetic material ____________

a) Increases

b) Decreases

c) Remains constant

d) First increases and then decreases

Answer: a

Explanation: Magnetic susceptibility of a ferromagnetic material decreases with increase in temeprature.

8. With an increase in temperature, magnetic susceptibility of an anti-ferromagnetic material ____________

a) Increases

b) Decreases

c) First decreases and then increases

d) First increases and then decreases

Answer: d

Explanation: Susceptibility of an anti-ferromagnetic material is first increases and then decreases with increase in temperature.

9. With an increase in the area of hysteresis curve, power loss will ___________

a) Increases

b) Decreases

c) First decreases and then increases

d) First increases and then decreases

Answer: a

Explanation: Power loss is directly proportional to the area of hysteresis curve.

10. Magnetic Bubbles are used as __________

a) Storage device

b) Strain gauge

c) Thermostat

d) Potentiometer

Answer: a

Explanation: Magnetic bubbles are small magnetized areas used as storage devices . One good thing about magnetic bubbles are they do not disappear when power is turned off.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Electrical Properties Of Materials”.

1. Which of the following is the de Broglie’s equation ?

a) λ = h/mv

b) λ = h/m

c) λ = h/v

d) λ = mv/h

Answer: a

Explanation: The equation, λ = h/mv is known as de Broglie’s equation. This equation represents the wave-particle duality of an electron.

2. With an increase in the mean free path of electrons, materials conductivity ____________

a) increases

b) decreases

c) remains constant

d) first increases and then decreases

Answer: a

Explanation: Conductivity of a material increases with an increase in the mean free path of electrons. Mean free path is nothing but the average distance travelled by an electron between two successive collisions.

3. What is the resistivity of silver  at room temperature?

a) 1.59 × 10 -2

b) 1.59 × 10 -3

c) 1.59 × 10 -5

d) 1.59 × 10 -9

Answer: d

Explanation: Silver has lowest conductivity. The resistivity of silver is 1.59 × 10 -9 Ω-m.

4. What is the resistivity of iron  at room temperature?

a) 9.71 × 10 -2

b) 9.71 × 10 -8

c) 9.71 × 10 -5

d) 9.71 × 10 -9

Answer: b

Explanation: Iron has medium conductivity. The resistivity of iron is 9.71 × 10 -8 Ω-m.

5. What is the resistivity of bismuth  at room temperature?

a) 1.29 × 10 -6

b) 1.29 × 10 -3

c) 1.29 × 10 -5

d) 1.29 × 10 -9

Answer: a

Explanation: Bismuth has low conductivity. The resistivity of iron is 1.29 × 10 -6 Ω-m.

6. What is the energy gap  of an insulator?

a) E g < 3 ev

b) E g < 1 ev

c) E g < 0 ev

d) E g > 3 ev

Answer: d

Explanation: The energy gap  of an insulator is approximately equal to 15 ev.

7. What is the energy gap  of a metal?

a) E g < 3 ev

b) E g < 1 ev

c) E g > 1 ev

d) E g > 3 ev

Answer: b

Explanation: Metals are nothing but electrical conductors. The energy gap of a conductor is very small and equal to 1 ev.

8. If a copper wire of 200 m length having 0.44mm diameter has resistance of 20 Ohm, then find its specific resistance .

a) 1.520 × 10 -8

b) 1.520 × 10 -7

c) 1.520 × 10 -6

d) 1.520 × 10 -5

Answer: a

Explanation: A = 3.14×d 2 /4 and resistivity = R×A/l, where ‘A’ is the area of cross section of wire, ρ is specific resistance, R = resistance, d = diameter, l = length.

Thus, A = 3.14×d 2 /4 = 3.14× 2 /4 = 0.152 mm 2 , resistivity = R×A/l =  × 10 -6 = 1.520 × 10 -8 .

9. If a copper wire of 10 m length having 0.44mm diameter has resistance of 2 Ohm, then what will be the specific resistance ?

a) 1.520 × 10 -8

b) 3.041 × 10 -8

c) 1.520 × 10 -6

d) 1.520 × 10 -5

Answer: b

Explanation: A = 3.14×d 2 /4 and resistivity = R×A/l, where ‘A’ is the area of cross section of wire, ρ is specific resistance, R = resistance, d = diameter, l = length.

Thus, A = 3.14×d 2 /4 = 3.14× 2 /4 = 0.152 mm 2 , resistivity = R×A/l =  × 10 -6 = 3.041 × 10 -8 .

10. With an increase in temperature, the resistance of a semiconductor ____________

a) increases

b) decreases

c) remains Constant

d) first increases and then decreases

Answer: b

Explanation: Semiconductors have a negative temperature coefficient of resistance; thus resistance increases with decreasing temperature.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction To Plastics”.

1. The polymerization of two or more chemically similar monomers forming a long molecular chain is termed as ____________

a) addition polymerization

b) copolymerization

c) condensation polymerization

d) step-growth polymerization

Answer: a

Explanation: Addition polymerization  involves addition of two or more ‘similar’ monomers to form a long chain molecule. In, addition polymerization, empirical formula is the same as that of monomer. Polyolefins are formed through addition polymerization.

2. The polymerization of two or more chemically different monomers forming a long molecular chain is termed as ____________

a) addition polymerization

b) copolymerization

c) condensation polymerization

d) chain growth polymerization

Answer: b

Explanation: Copolymerization involves polymerization of two or more different monomers to form a long chain molecule. A well-known ‘Nylon 66’ is a copolymer of hexamethylenediamine and adipic acid.

3. The polymerization of two or more chemically different monomers forming a cross link polymer along with a by-product  is termed as ____________

a) addition polymerization

b) copolymerization

c) condensation polymerization

d) chain-growth polymerization

Answer: c

Explanation: Condensation polymerization  involves condensation  of different monomers to form a cross linked polymer. In, condensation polymerization, empirical formula is different as that of monomer. Polymers like polyamides, polyacetals and proteins are formed through condensation polymerization.

4. Which of the following additive is used as an initiator in polymerization reaction?

a) Benzoyl peroxide

b) Mica

c) Glass powder

d) Hydrogen peroxide

Answer: d

Explanation: Addition polymerization involves three steps for form an addition polymer, known as initiation, propagation and termination. In the initiation step, an initiator like hydrogen peroxide, easily split to form two species with a free electron attached to each.

5. Thermosetting plastics have ____________

a) 1-Degree bond

b) 2-Degree bond

c) 3-Degree bond

d) 0-Degree bond

Answer: a

Explanation: A thermosetting plastic is a polymer which gets irreversibly hardened when heated. They have a three-dimensional network of ‘1-degree’ primary bond. A well-known example of this kind are bakelite, polyester and epoxy resin, etc.

6. Which of the following is a primary bond network of thermosetting plastics?

a) 1-Dimensional

b) 3-Dimensional

c) 2-Dimensional

d) 0-Dimensional

Answer: b

Explanation: Thermosetting plastics have a three-dimensional network of ‘1-degree’ primary bond.

7. Thermoplastics have _____________

a) 1-Degree bond

b) 2-Degree bond

c) 3-Degree bond

d) 0-Degree bond

Answer: b

Explanation: A thermoplastic is a polymer which gets softened when heated. They have a one-dimensional network of ‘2-degree’ secondary bond. A well-known example of this kind are PET , PVC , and PP  etc.

8. Which of the following is a secondary bond network of thermoplastics?

a) 1-Dimensional

b) 3-Dimensional

c) 2-Dimensional

d) 0-Dimensional

Answer: a

Explanation: Thermoplastics have a one-dimensional network of ‘2-degree’ secondary bond.

9. Thermoplastics become softer upon heating.

a) True

b) False

Answer: a

Explanation: Thermoplastics have 1-dimensional secondary bond structure, due to this, when heated, their individual polymer chains can slide one over other, thus making them softer.

10. Thermosetting plastics become softer upon heating.

a) True

b) False

Answer: b

Explanation: Thermosetting plastics have 2-dimensioanl primary bond structure , thus making them stronger upon heating.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction To Ceramics”.

1. Which of the following are a ceramics solids?

a) Metallic, inorganic and amorphous solids

b) Non-metallic, organic and amorphous solids

c) Non-metallic, inorganic and amorphous solids

d) Non-metallic, inorganic and crystalline solids

Answer: c

Explanation: Ceramics are non-metallic, inorganic, amorphous solids and are mostly oxides of metals. Ceramics possess low tensile strength and are brittle.

2. Which of the following is a correct refractory type of quartz?

a) Acidic

b) Basic

c) Neutral

d) Amphoteric

Answer: a

Explanation: Quartz is an acidic refractory and are mostly used in open-hearth furnaces, gas retorts and in glass furnaces.

3. Which one of the following is not an acidic refractory?

a) Quartz

b) Sand

c) Silica brick

d) Dolomite

Answer: d

Explanation: Dolomite is a basic refractory.

Refractories

Differentiating Parameter Acidic Refractories Basic Refractories Neutral Refractories

Typical Usage Used in furnaces, where charge and slag are acidic in nature. Used in furnaces, where the charge and slag are basic in nature. Used in furnaces, where the charge and slag either acidic or basic in nature.

Examples Fireclay, Silica, Quartz, Zirconia, etc. Magnesia, Alumina, Dolomite, etc. Chromate, Carbide, Mullite, etc.

4. Which one of the following is not a basic refractory?

a) Magnesite

b) Sand

c) Dolomite

d) Alumina

Answer: b

Explanation: Most of the silica-based refractories, like fire clay, bricks and sand are of acidic refractories.

5. Which one of the following is a neutral refractory?

a) Quartz

b) Sand

c) Silica brick

d) Silicon carbide

Answer: d

Explanation: Silicon carbide is a neutral refractory, whereas sand, quartz and silica brick are acidic refractories.

6. For a M10 grade RCC , the ratio of cement to aggregate to the sand is?

a) 1:2:3

b) 1:3:4

c) 1:3:6

d) 1:2:6

Answer: c

Explanation: M10 grade of RCC have cement to aggregate to sand ratio equal to 1:3:6.

7. Production of thin sheets of a flexible tape by casting in the particulate forming process may be termed as _________________

a) slip casting

b) hydroplastic forming

c) powder casting

d) tape casting

Answer: d

Explanation: Tape casting is a very old process and is used in the formation of flexible tapes.

8. Which one of the following can act as a modifier in glass forming process?

a) Silicon dioxide

b) Sodium oxide

c) Magnesium oxide

d) Phosphorous oxide

Answer: c

Explanation: Magnesium oxide is used as a viscosity modifier, thus making glass melt viscosity to be in the desired range for proper formation of the filaments.

9. The word ceramic stands for which of the following meaning?

a) Soft

b) Burnt

c) Hard

d) Tough

Answer: b

Explanation: Ceramics convey the meaning of burnt materials. This is so because in olden days, making pottery and bricks involves burning wood, coal and gas.

10. Which one of the following ceramics can be used as a pigment in paints?

a) Silicon carbide

b) Silicon oxide

c) Aluminum oxide

d) Titanium oxide

Answer: d

Explanation: Titanium white  used as a pigment in pains. It is used so, because of its SFC  nature.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction To Composites”.

1. Composites can be classified based on ___________

a) matrix type

b) reinforcement constituent

c) matrix type & Reinforcement constituent

d) neither on matrix type nor on reinforcement constituent type

Answer: c

Explanation: Composites cans be classified based on matrix types and reinforcement constituent types as shown below:

2. Which of the following is not a laminar composite?

a) Bimetallic

b) Cladding

c) Paints

d) Wood

Answer: d

Explanation: Wood is not a laminar composite. Bimetallic, cladding and paints are considered as laminar composites.

3. The composite constituents of both matrix and reinforcements are softer.

a) True

b) False

Answer: b

Explanation: Matrix constituents are generally softer whereas reinforced constituents provide hardness to the composites.

4. In sandwich composites, which of the following material can be used for filling purpose?

a) Wood

b) Cement

c) Polymer

d) All of the mentioned

Answer: d

Explanation: Wood, cement, and polymer can be used to fill the gap in sandwich composites.

5. Which of the following have a greater impact on longitudinal strength of reinforced composites?

a) Fiber orientation

b) Fiber strength

c) Fiber length

d) Fiber diameter

Answer: b

Explanation: Longitudinal strength of reinforced composites is directly proportional to its fiber strength.

6. Which of the following may alter the mechanical properties of reinforced composites?

a) Constituent properties

b) Fiber length

c) Fiber orientation

d) All of the mentioned

Answer: d

Explanation: Constituent properties, fiber length etc affect the overall property of reinforced composites.

7. Which of the following property can be enhanced by reinforcing an aluminum alloy?

a) Density

b) Torsion resistance

c) Wear resistance

d) Strength

Answer: c

Explanation: It is observed that for an aluminium alloy matrix composites when reinforced with ceramic particles, there is an increase in the wear resistance.

8. Which of the following is the correct size range of dispersoids  in dispersion strengthened composites?

a) 0.0001-0.0009

b) 0.01-0.1

c) 0.1-1.0

d) 2.0-2.7

Answer: b

Explanation: Dispersoids size varies from 0.01 micrometre to 0.1 micrometre. They are very small.

9. Which of the following is correct dimensional of flake composites?

a) 1-Dimensional

b) 2-Dimensional

c) 3-Dimensional

d) 4-Dimensional

Answer: b

Explanation: Flake composites are two dimensional in nature and can be easily represented on a plane of the paper.

10. Fire point of composite is high.

a) True

b) False

Answer: b

Explanation: Composites have low fire and flash point, and this is one of the main drawbacks.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Tool Geometery and Nomenclature-1”.

1. Angle between the rake face and plane perpendicular to rake face is known as:

a) Side rake angle

b) Side relief angle

c) End relief angle

d) Back rake angle

Answer: a

Explanation: Side rake angle is the angle between the rake face and plane perpendicular to rake face.

2. Angle between the rake face flank of tool and perpendicular line drawn from cutting point to base of tool is known as:

a) Side rake angle

b) Side relief angle

c) End relief angle

d) Back rake angle

Answer: b

Explanation: Side relief angle is the angle between the flank of tool and perpendicular line drawn from cutting point to base of tool.

3. Angle between side cutting edge and axis of tool is known as:

a) Side rake angle

b) Side relief angle

c) Side cutting edge angle

d) Back rake angle

Answer: c

Explanation: Side cutting angle is the angle between side cutting edge and axis of tool.

4. Angle between end cutting edge and axis of tool is known as:

a) Side rake angle

b) Side relief angle

c) End cutting edge angle

d) Back rake angle

Answer: c

Explanation: End cutting angle is the angle between end cutting edge and axis of tool.

5. Angle between side cutting edge and end cutting edge in the top surface plane of tool.

a) Side rake angle

b) Side relief angle

c) Side cutting edge angle

d) Nose angle

Answer: d

Explanation: Nose angle is the angle between side cutting edge and end cutting edge.

6. With an increase in lip angle keeping side rake angle constant, strength of tool.

a) Increases

b) Decreases

c) Remains constant

d) None of the mentioned

Answer: a

Explanation: Thickness of tool tip increase with an increase in lip angle, hence the strength of tool increase.

7. For large positive back rake angle, tool will be

a) Weaker

b) Stronger

c) Smoother

d) Harder

Answer: a

Explanation: With the increase in positive back rake angle, lip angle decreases and tool tip become thin.

8. For large negative back rake angle, tool will be

a) Weaker

b) Stronger

c) Smoother

d) Harder

Answer: b

Explanation: With an increase in negative back rake angle, lip angle increases and tool tip become thick and hence the strength of tool will increase.

9. Which of the following will give better chip flow?

a) Positive back rake angle tool

b) Negative back rake angle tool

c) Zero back rake angle tool

d) None of the mentioned

Answer: a

Explanation: With positive back rake angle, lip angle decreases and space for chip flow increases and hence it will give better chip flow.

10. Which of the following will give large friction during chip flow?

a) Positive back rake angle tool

b) Negative back rake angle tool

c) Zero back rake angle tool

d) Small lip angle tool

Answer: b

Explanation: With negative back rake angle, lip angle increases and space for chip flow decreases due to which it offers large resistance to chip flow.

This set of Manufacturing Engineering Interview Questions & Answers focuses on “Tool Geometery and Nomenclature-2”.

1. Positive rake angle is given for machining of:

a) Brittle material

b) Ductile material

c) Both hard and soft material

d) None of the mentioned

Answer: b

Explanation: Positive rake angle have better chip flow. As the amount of chip flow in ductile material is large, hence positive back rake angle tool will be a better option for machining ductile material.

2. Negative back rake angle is given for machining of:

a) Brittle and hard material

b) Soft material

c) Ductile material

d) Soft and ductile material

Answer: a

Explanation: Brittle material has smaller amount of chip flow and are very strong. As negative back angle tool are very strong, hence these are used for machining of brittle and hard material.

3. Which of the following will give maximum chip flow during machining?

a) Hard material

b) Ductile material

c) Brittle material

d) All of the mentioned

Answer: b

Explanation: Brittle material breaks very easily due to which they have maximum chip flow.

4. With an increase in rake angle of tool, tool life will

a) Increase

b) Decrease

c) Remains constant

d) First increase then decrease

Answer: d

Explanation: With an increase in rake angle chip flow rate increases and hence the heat generated is carried away with chips at faster rate due to which tool life increases. For large back rake angle, tool become very thin and its life decrease.

5. What is the optimum value of positive rake angle in degrees for maximum tool life?

a) 10

b) 12

c) 15

d) 20

Answer: c

Explanation: At 15 degree chip removal rate and strength of tool are optimum and hence tool life will be maximum.

6. For machining of carbide material which of the following tool will be preferred?

a) Large positive rake angle tools

b) Large negative rake angle tools

c) Zero rake angle tools

d) Small point angle tools

Answer: b

Explanation: Carbide materials are very hard hence strong tool is required for their machining. Tools with large negative back rake angle are stronger.

7. Which of the following tool will give the best result for machining of brass?

a) Large positive rake angle tools

b) Large negative rake angle tools

c) Zero rake angle tools

d) Small point angle tools

Answer: c

Explanation: Brass is neither very hard nor very soft and zero rake angle tool would be the best option for machining of brass.

8. With an increase in side cutting edge angle keeping width of cut constant, depth of cut will

a) Increase

b) Decrease

c) First increase then decrease

d) Remains constant

Answer: b

Explanation: Depth of cut is directly proportional to cos of side cutting edge angle, hence it decreases with increase in side cutting edge angle.

9. With an increase in rake angle of tool, tool life will

a) Increase

b) Decrease

c) Remains constant

d) First increase then decrease

Answer: d

Explanation: With an increase in side cutting edge angle width of cut decreases, hence the chip removal rate is good due to which toll life increases. After some limit increasing side cutting angle will decrease tool life to increase in interaction of tool with work piece.

10. What is the optimum value of side cutting edge in degrees for maximum tool life?

a) 20

b) 22

c) 25

d) 30

Answer: d

Explanation: At 30 degree chip removal rate and strength of tool are optimum and hence tool life will be maximum.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Tool Wear and Failure”.

1. Thermal cracking of tools occurs at

a) Low temperature

b) High temperature

c) Low cutting speed

d) None of the mentioned

Answer: b

Explanation: At high temperature tool may lose its hardness property which results in failure of tool and this phenomenon is known as thermal cracking.

2. Mechanical chipping may occur in which of the following tool?

a) Diamond tool

b) Mild Steel tool

c) HSS tool

d) None of the mentioned

Answer: a

Explanation: Mechanical chipping occurs in brittle tools. Here diamond is a brittle material.

3. With the passage of time, there is loss in weight of tool, this phenomenon is known as:

a) Thermal cracking

b) Mechanical chipping

c) Softening

d) Gradual Wear

Answer: d

Explanation: Loss of weight of tool with respect to time is known as gradual wear.

4. Crater wear occurs at

a) Tool flank

b) Tool shank

c) Tool face

d) None of the mentioned

Answer: c

Explanation: Tool face is weaker for crater wear than shank or flank.

5. Which of the following is correct about crater wear?

a) Occurs more in soft tool

b) Occurs more hard tool

c) Occurs more in brittle tool

d) None of the mentioned

Answer: a

Explanation: Crater wear occurs in soft tools because their face gets eroded easily during flow of chips over the face.

6. Flank wear occurs at

a) Tool flank below cutting edge

b) Tool shank

c) Tool face

d) None of the mentioned

Answer: a

Explanation: Tool flank are generally subjected to flank wear due to rubbing action of tool. Cutting edge may be side cutting edge or end cutting edge.

7. What is the maximum allowed value of VB in mm for HSS tool used with cast iron work piece for rough machining?

a) 0.5

b) 1

c) 1.5

d) 2

Answer: d

Explanation: VB denotes the width of wear land. Maximum 2mm width of wear land is allowed in flank wear.

8. What is the maximum allowed value of VB in mm for HSS tool used with cast steel work piece for rough machining?

a) 0.5

b) 1

c) 1.5

d) 2

Answer: b

Explanation: VB denotes the width of wear land. Maximum 1mm width of wear land is allowed in flank wear.

9. What is the maximum allowed value of VB in mm for carbide tool used with cast iron work piece for a cutting condition of feed>0.3mm/rev?

a) 0.5

b) 1

c) 1.5

d) 2

Answer: d

Explanation: VB denotes the width of wear land. Maximum 1mm width of wear land is allowed in flank wear.

10. What is the maximum allowed value of VB in mm for carbide tool used with steel work piece for a cutting condition of feed>0.3mm/rev?

a) 0.5

b) 1

c) 1.7

d) 2

Answer: c

Explanation: VB denotes the width of wear land. Maximum 1.7mm width of wear land is allowed in flank wear.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Cutting Tool Material-1”.

1. If a percentage of cobalt in Tungsten carbide tool increases, then toughness of tool will

a) Increase

b) Decrease

c) Remains Constant

d) First increase then decrease

Answer: a

Explanation: With an increase in percentage of cobalt toughness increases. Carbides are very hard and have very good red hot hardness property and hence most suitable for machining of hard and brittle material.

2. Which of the following tools is most suitable for very hard and brittle material?

a) HSS

b) Cast-cobalt alloy

c) Carbides

d) None of the mentioned

Answer: c

Explanation: Carbides are very hard and have very good red hot hardness property and hence most suitable for machining of hard and brittle material.

3. High speed steels are most suitable for

a) High Positive rake angle tools

b) High Negative rake angle tools

c) Zero Rake angle tools

d) None of the mentioned

Answer: a

Explanation: HSS are very tough and fracture resistance and suitable for high positive rake angle tool. With an increase in percentage of cobalt toughness increases.

4. Which of the following tool material will offer lower friction and higher resistance to cracks and wear?

a) HSS

b) TiC

c) WC

d) TiCN

Answer: d

Explanation: TiCN is a coated tool and hence offer very less friction and there is much low chance of wear in tool due to coating on tool.

5. Which of the following tool material will offer lower friction and higher resistance to cracks and wear?

a) HSS

b) TiC

c) Cast cobalt alloys

d) Coated tools

Answer: d

Explanation: Coated tool offers very less friction and there is much low chance of wear in tool due to coating on tool.

6. Which of the following material can be used for coating on tools?

a) HSS

b) TiCN

c) WC

d) cBN

Answer: b

Explanation: TiCN can be used for coating of tool while, HSS, WC and cBN are tool materials. With the increase in percentage of cobalt toughness increases.

7. Cutting tool should maintain its hardness.

a) True

b) False

Answer: a

Explanation: Life of cutting tool is ends when it looses its hardness. With increase in percentage of cobalt toughness increases.

8. Thermal conductivity of cutting tool must be

a) High

b) Low

c) Very low

d) None of the mentioned

Answer: a

Explanation: For faster removal of heat, cutting tool must have high thermal conductivity. Thermal conductivity of cutting tool must be high.

9. Hot hardness of cutting of cutting tool should be

a) Large

b) Small

c) Very small

d) None of the mentioned

Answer: a

Explanation: Cutting tool must be able to withstand high temperature. Hot hardness of cutting of cutting tool should be large.

10. Wearing resistance of cutting tool must be

a) High

b) Low

c) Very low

d) None of the mentioned

Answer: a

Explanation: Cutting tool has high capability to resist wear. Wearing resistance of cutting tool must be high.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Cutting Tool Material-2”.

1. What is the percentage of carbon tungsten in T-series of high speed steel?

a) 20

b) 18

c) 16

d) 14

Answer: b

Explanation: 18% of tungsten is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

2. What is the percentage of carbon chromium in T-series of high speed steel?

a) 0

b) 8

c) 6

d) 4

Answer: d

Explanation: 4% of chromium is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

3. What is the percentage of vanadium in T-series of high speed steel?

a) 2

b) 1

c) 6

d) 4

Answer: b

Explanation: 1% of vanadium is present in T-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

4. What is the percentage of Molybdenum in M-series of high speed steel?

a) 12

b) 21

c) 16

d) 24

Answer: b

Explanation: 21% of molybdenum is present in M-series of high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

5. M-series high speed steel has more efficiency than T-series high speed steel.

a) True

b) False

Answer: a

Explanation: M series have more cutting efficiency than T series high speed steel. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

6. Presence of Chromium in T-series steel imparts

a) Hardness

b) Corrosion resistance

c) Abrasion resistance

d) Toughness

Answer: b

Explanation: Chromium imparts corrosion and oxidation resistance to a material. It is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

7. Which of the following element is responsible for providing red hot hardness property to T-series high speed steel?

a) W

b) Cr

c) V

d) Mo

Answer: a

Explanation: Tungsten imparts red hot hardness i.e. property to impart hardness at high temperature. HSS is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

8. If percentage of cobalt in Tungsten carbide tool increases, then the strength of the tool will

a) Increase

b) Decrease

c) Remains Constant

d) First increase then decrease

Answer: b

Explanation: With an increase in the percentage of cobalt hardness decreases. HSS is used for cutting at low speeds rather than at high speed as its name implies but it cuts faster.

9. If percentage of cobalt in Tungsten carbide tool increases, then hardness of tool will

a) Increase

b) Decrease

c) Remains Constant

d) First increase then decrease

Answer: b

Explanation: With an increase in the percentage of cobalt, hardness and strength decreases.

10. If percentages of cobalt in Tungsten carbide tool increases, then wear resistance of tool will

a) Increase

b) Decrease

c) Remains Constant

d) First increase then decrease

Answer: b

Explanation: With increase in the percentage of cobalt hardness, strength and wear resistance decreases.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Cutting Fluid and Tool Temperature”.

1. Primary deformation zone in metal cutting operation is located at:

a) Around shear plane

b) Tool chip interface

c) Tool work piece interface

d) Tool face

Answer: a

Explanation: Primary deformation is the zone where maximum deformation occurs and occurs around the shear plane.

2. Secondary deformation zone in metal cutting operation is located at:

a) Shear plane

b) Tool chip interface

c) Tool work piece interface

d) Tool face

Answer: b

Explanation: Secondary deformation zone has medium level of deformation and generally occurs in tool chip interface.

3. Temperature rise in primary deformation zone is generally due to:

a) Plastic deformation of metal in shear zone

b) Friction between tool and chip

c) Rubbing action of tool piece with work piece

d) None of the mentioned

Answer: a

Explanation: Due to plastic deformation of metal during chip formation, there is a gradual rise in temperature.

4. Temperature rise in secondary deformation zone is generally due to:

a) Plastic deformation of metal in shear zone

b) Friction between tool and chip

c) Rubbing action of tool piece with work piece

d) None of the mentioned

Answer: b

Explanation: Temperature rises due to relative motion between chip and tool against some friction. Friction is responsible for the heat generation.

5. If heat transferred to the atmosphere is neglected, then the average amount of heat in % carried away by chips is nearly equal to:

a) 70

b) 15

c) 20

d) 96

Answer: a

Explanation: About 70% of the heat is carried away by chips, if heat transferred to surrounding is neglected.

6. If heat transferred to atmosphere is neglected, then the average amount of heat in % transferred to tool is nearly equal to:

a) 70

b) 15

c) 20

d) 96

Answer: b

Explanation: About 15% of the total heat is transferred to tool, if heat transferred to the surrounding is neglected.

7. If heat transferred to atmosphere is neglected, then the average amount of heat in % transferred to work piece is nearly equal to:

a) 70

b) 15

c) 20

d) 96

Answer: b

Explanation: About 15% of the total heat is transferred to work piece if heat transferred to the surrounding is neglected.

8. By increasing cutting speed, amount of heat generated

a) Increases

b) Decreases

c) Remains constant

d) None of the mentioned

Answer: a

Explanation: With increase in cutting speed, friction increases and hence the amount of heat generated increases.

9. By increasing feed rate, amount of heat generated

a) Increases

b) Decreases

c) Remains constant

d) None of the mentioned

Answer: b

Explanation: With an increase in feed rate, friction time for generating heat decreases and hence the amount of heat generated increases.

10. Amount of heat generated in shear plane is:

a) Directly proportional to shear angle

b) Inversely proportional to shear angle

c) Does not depend on shear angle

d) None of the mentioned

Answer: b

Explanation: With an increase in shear angle amount of plastic deformation decreases and hence the amount of heat generated decreases.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Mechanics of Cutting-1”.

1. Which of the following is correct about chip thickness ratio ‘r’?

a) r<1

b) r=1

c) r>1

d) None of the mentioned

Answer: a

Explanation: Uncut chip thickness is always less than cut chip thickness and ‘r’ is the ratio of cut chip thickness to uncut chip thickness.

2. If t 1 denotes the uncut chip thickness and t 2 denotes cut chip thickness ratio then, which of the following equation is correct about chip thickness ratio ‘r’?

a) r=t 1 /t 2

b) r=t 1 /t 2

c) r=t 1 *t 2

d) None of the mentioned

Answer: a

Explanation: ‘r’ is the ratio of cut chip thickness to uncut chip thickness. Here t1 is the uncut chip thickness and t2 is the cut chip thickness.

3. Which of the following is the correct relation for chip thickness ratio ‘r’?

Given that: φ=shear angle

α=rake angle

a) tan φ= cosα/

b) tan φ= rcosα/

c) tan φ= rcosα/

d) tan φ= cosα/

Answer: b

Explanation: Value of chip thickness ratio is given by: tan φ= rcosα/ . ‘r’ is the chip thickness ratio, which is the ratio of cut chip thickness to uncut chip thickness.

4. Horizontal force exerted by tool on work piece is known as

a) Cutting force

b) Frictional resistance

c) Backing up force

d) Shear force

Answer: a

Explanation: Cutting force is the force by which tool cut work piece in horizontal direction. It is responsible for the cutting action during machining.

5. Metal resistance to shear during chip formation is known as

a) Cutting force

b) Frictional resistance

c) Backing up force

d) Shear force

Answer: d

Explanation: Metal resistance to shear in chip formation is known as shear plane. It acts on a shear plane. It cause distortion in shape and angle.

6. Force exerted by work piece on chip in normal direction of shear plane is known as

a) Cutting force

b) Frictional resistance

c) Backing up force

d) Shear force

Answer: c

Explanation: Backing up force is the force exerted by work piece on chip in normal direction of shear plane. It does not cause any distortion or shape change.

7. Force exerted by tool on chip normal to tool face is known as

a) Cutting force

b) Frictional resistance

c) Backing up force

d) Shear force

Answer: b

Explanation: Frictional resistance is the resistance offered between tool and chip interface. It causes generation of heat during welding.

8. Which of the following assumption is not valid for merchant circle diagram?

a) Continuous Chips

b) Discontinuous chips

c) Cutting edge remains sharp

d) No built up edge

Answer: b

Explanation: Chips are assumed to be continuous in nature in drawing of merchant circle. In actual practice, thickness may not be uniform.

9. Which of the following assumption is not valid for the merchant circle diagram?

a) Continuous Chips

b) Sharpness of cutting edge reduces gradually

c) Cutting edge remains sharp

d) No built up edge

Answer: b

Explanation: Sharpness of cutting edge is assumed to be constant during the cutting process. In actual machining process sharpness of cutting edge decreases as time passes.

10. Which of the following is correct equation for shear force F S =? φ is the shear angle?

a) F S =F C cosφ-F T sinφ

b) F S =F C cosφ/F T sinφ

c) F S =F C cosφ*F T sinφ

d) F S =F C cos&o#966;+F T sinφ

Answer: a

Explanation: F S =F C cosφ-F T sinφ is the correct relation of shear force in terms of horizontal cutting force, Tangential cutting force and shear angle.

This set of Manufacturing Engineering Interview Questions & Answers focuses on “Mechanics of Cutting”.

1. Chip flow velocity during machining process is 0.2m/s with chip thickness ratio of 0.6. What is the value of cutting velocity?

a) 0.33m/s

b) 0.43m/s

c) 0.23m/s

d) 0.13m/s

Answer: a

Explanation: Chip flow velocity= chip thickness ratio * cutting velocity. Hence cutting velocity = 0.33m/s.

2. Chip flow velocity during machining process is 1.2m/s with chip thickness ratio of 0.6. What is the value of cutting velocity?

a) 1.33m/s

b) 4m/s

c) 3m/s

d) 2m/s

Answer: d

Explanation: Chip flow velocity= chip thickness ratio * cutting velocity. Hence cutting velocity = 2m/s.

3. Shear velocity during machining process is 0.2m/s with chip thickness ratio of 0.6. Shear angle is 30 degree and rake angle is 15 degree. What is the value of cutting velocity?

a) 0.33m/s

b) 0.43m/s

c) 0.20m/s

d) 0.13m/s

Answer: c

Explanation: Chip flow velocity= chip thickness ratio * cutting velocity and chip flow velocity= shear velocity*sin /).

4. Shear velocity during the machining process is 1.2m/s with chip thickness ratio of 0.6. Shear angle is 30 degree and rake angle is 15 degree. What is the value of cutting velocity?

a) 0.33m/s

b) 0.43m/s

c) 1.20m/s

d) 0.13m/s

Answer: c

Explanation: Chip flow velocity= chip thickness ratio * cutting velocity and chip flow velocity= shear velocity*sin /).

5. Feed force of 210Kg and cutting force of 310Kg are applied using a tool of rake angle 10 degrees. If chip thickness ratio is 0.36, what will be the value of the shear angle in degrees?

a) 20.17

b) 44.13

c) 30.606

d) 21.571

Answer: a

Explanation: tan = )/ ). Where r is the chip thickness ratio.

6. Feed force of 210Kg and cutting force of 310Kg are applied using a tool of rake angle 10 degrees. If chip thickness ratio is 0.36, what will be the value of shear force in Kg?

a) 20.17

b) 44.13

c) 30.606

d) 215.71

Answer: d

Explanation: tan = )/ ). Shear force=Cutting force*cos-feed force*sin .

7. Feed force of 210Kg and cutting force of 310Kg are applied using a tool of rake angle 10 degrees. If chip thickness ratio is 0.36, what will be the value of normal force in Kg?

a) 20.17

b) 44.13

c) 306.06

d) 215.71

Answer: a

Explanation: tan = )/ ). Normal force=-Cutting force*sin +feed force*cos.

8. Feed force of 210Kg and cutting force of 310Kg are applied using a tool of rake angle 10 degrees. If chip thickness ratio is 0.36, what will be the value of a coefficient of friction?

a) .20

b) .44

c) .97

d) .21

Answer: c

Explanation: tan = )/ ). Use merchant circle diagram to find coefficient of friction.

9. Feed force of 210Kg and cutting force of 310Kg are applied using a tool of rake angle 10 degrees. If chip thickness ratio is 0.36, what will be the value of friction angle?

a) 20.17

b) 44.13

c) 30.606

d) 21.571

Answer: b

Explanation: tan = )/ ). Use merchant circle diagram to find coefficient of friction and then use, Coefficient of friction= tan .

10. Which of the following will have a maximum amount of chips during machining?

a) Ductile material

b) Brittle material

c) Cast iron

d) None of the mentioned

Answer: a

Explanation: Ductile material produces more chip than brittle material.

This set of Manufacturing Engineering test focuses on “Cutting Mechanics”.

1. In the orthogonal cutting of metals _________

a) the cutting edge of the tool is perpendicular to the direction of tool travel

b) the cutting forces occur in one direction only

c) the cutting edge is wider than the depth of cut

d) all of the mentioned

Answer: a

Explanation: In orthogonal cutting of metals, the cutting edge of the tool is perpendicular to the direction of tool travel. The cutting edge clears the width of the workpiece on either ends.

2. In oblique cutting of the metals, the cutting edge of the tool is

a) perpendicular to the workpiece

b) perpendicular to the direction of tool travel

c) parallel to the direction of tool travel

d) inclined at an angle less than 90 0 to the direction of tool travel

Answer: d

Explanation: The chip flows on the tool face at an angle of less than 90 0 with the normal on the cutting edge.

3. Discontinuous chips are formed during machining of

a) brittle metals

b) ductile metals

c) hard metals

d) soft metals

Answer: a

Explanation: Discontinuous chips are formed during machining of brittle metals while continuous chips are formed during machining of ductile materials.

4. The ductile materials, during machining, produces

a) continuous chips

b) discontinuous chips

c) continuous chips with built up edge

d) none of the mentioned

Answer: a

Explanation: Discontinuous chips are formed during machining of brittle metals while continuous chips are formed during machining of ductile materials.

5. Continuous chips with built up edge are formed during machining of

a) brittle metals

b) ductile metals

c) hard metals

d) soft metals

Answer: b

Explanation: Discontinuous chips are formed during machining of brittle metals while continuous chips with built up edge are formed during machining of ductile materials at low cutting speed.

6. The factor responsible for the formation of discontinuous chips is

a) low cutting speed and large rake angle

b) low cutting speed and small rake angle

c) high cutting speed and large rake angle

d) high cutting speed and small rake angle

Answer: b

Explanation: The low cutting speed and small rake angle of the tool are responsible for the formation of discontinuous chips while high cutting speed and large rake angle of the tool will result in the formation of continuous chips.

7. The high cutting speed and large rake angle of the tool will result in the formation of

a) continuous chips

b) discontinuous chips

c) continuous chips with built up edge

d) none of the mentioned

Answer: a

Explanation: The low cutting speed and small rake angle of the tool are responsible for the formation of discontinuous chips while high cutting speed and large rake angle of the tool will result in the formation of continuous chips.

8. A built-up-edge is formed while machining __________

a) ductile materials at high speed

b) ductile materials at low speed

c) brittle materials at high speed

d) brittle materials at low speed

Answer: b

Explanation: When machining ductile materials, conditions of high local temperature and extreme pressure in the cutting zone and also high friction in the tool chip interface, may cause the work material to adhere or weld to the cutting edge of the tool forming the built-up edge. Low-cutting speed contributes to the formation of the built-up edge. Increasing the cutting speed, increasing the rake angle and using a cutting fluid contribute to the reduction or elimination of built-up edge.

9. The continuous chips are in the form of long coils having the same thickness throughout.

a) True

b) False

Answer: a

Explanation: None

10. In oblique cutting system, the maximum chip thickness

a) occurs at the middle

b) may not occur at the middle

c) depends upon the material of the tool

d) none of the mentioned

Answer: b

Explanation: In orthogonal cutting, maximum chip thickness occurs at the middle but in oblique cutting, the maximum chip thickness may not occur at the middle.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Cutting Forces and Power”.

1. A single-point cutting tool with 12 0 C rake angle is used to machine a steel work-piece. The depth of cut, i.e., uncut thickness is 0.81 mm. The chip thickness under orthogonal machining condition is 1.8 mm. The shear angle is approximately

a) 22 0 C

b) 26 0 C

c) 56 0 C

d) 76 0 C

Answer: b

Explanation: Given : α= 12c, t= 0.81mm, tc= 1.8 mm

Shear angle, tanφ = [rcosα/1 – rsinα] ……….

Chip thickness ratio, r = t/t c

= 0.81/1.8

= 0.45

From equation , tanφ = [0.45cos12 0 /1 – 0.45sin12 0 ]

φ = tan -1  = 25.91 0 – 26 0 .

2. In a single point turning tool, the side rake angle and orthogonal rake angle are equal. ϕ is the principal cutting edge angle and its range is 0 0 0. The chip flows in the orthogonal plane. The value of ϕ is closest to

a) 0 0

b) 45 0

c) 60 0

d) 90 0

Answer: d

Explanation: Interconversion between ASA  system and ORS 

tanα s = sinφtanα − cosφtani

where α s = Side rake angle

α = orthogonal rake angle

φ = principle cutting edge angle = 0 0 0

i = inclination angle 

α s = α 

tanα s =sinφtanα − cosφtan(0 0 )

tanα s = sinφtanα

tanα s /tanα = sinφ

φ =sin -1 =90 0 .

3. In an orthogonal machining operation :

Uncut thickness = 0.5 mm

Cutting speed = 20 m/min

Rake angel = 15 0

Width of cut = 5 mm Chip thickness = 0.7 mm

Thrust force = 200 N Cutting force = 1200 N

The values of shear angle and shear strain, respectively, are

a) 30.3 0 and 1.98

b) 30.3 0 and 4.23

c) 40.2 0 and 2.97

d) 40.2 0 and 1.65

Answer: d

Explanation: Given : t= 0.5mm, V = 20 m/min, α= 15 0 , w= 5mm, t c = 0.7 mm,

F t = 200 N, F c = 1200 N

We know, from the merchant’s theory

Chip thickness ratio, r = t/t c = 0.5/0.7 = 0.714

For shear angle, tanφ = [rcosα/1 – rsinα]

Substitute the values, we get

tanφ = [0.714cos15 0 /1 – 0.714sin15 0 ] = 0.689/0.815 = 0.845

φ = tan -1  = 40.2 0

Shear strain, s = cotφ + tan

s = cot(40.2 0 ) + tan(40.2 0 − 15 0 )

= cot 40.2 0 + tan 25.2 = 1.183 + 0.470 = 1.65.

4. Which of the following parameters govern the value of the shear angle in continuous chip formation?

a) true feed

b) chip thickness

c) rake angle of the cutting tool

d) all of the mentioned

Answer: d

Explanation: To find a shear angle in continuous chip feed, rake angle, chip thickness, cutting ratio are required.

5. In determining the various forces on the chip, Merchant assumed that the

a) cutting edge of the tool is sharp and it does not make any flank contact with the workpiece

b) only continuous chip without built up edge is produced

c) cutting velocity remains constant

d) all of the mentioned

Answer: d

Explanation: None

6. Cutting forces can be measured using a

a) transducer

b) dynamometer

c) load cell

d) all of the mentioned

Answer: d

Explanation: Cutting forces can be measured using a force transducer , a dynamometer, or a load cell  mounted on the cutting-tool holder.

7. Transducers have a much __________ natural frequency and stiffness than dynamometers.

a) higher

b) lower

c) equal

d) none of the mentioned

Answer: a

Explanation: Transducers have a much higher natural frequency and stiffness than dynamometers, which are prone to excessive deflection and vibration.

8. In metal machining, the zone where the heat is generated due to friction between the moving chip and the tool face is called

a) friction zone

b) work tool contact zone

c) shear zone

d) none of the mentioned

Answer: a

Explanation: In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal, is called shear zone while the zone where the heat is generated due to friction between the moving chip and the tool face, is called friction zone.

9. In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal is called:

a) friction zone

b) work tool contact zone

c) shear zone

d) none of the mentioned

Answer: c

Explanation: In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal, is called shear zone while the zone where the heat is generated due to friction between the moving chip and the tool face, is called friction zone.

10. The ratio of the cutting force to the cross-sectional area being cut is called:

a) specific cutting force

b) thrust force

c) frictional force

d) none of the mentioned

Answer: a

Explanation: The ratio of the cutting force to the cross-sectional area being cut  is referred to as the specific cutting force. The thrust force, Ft, acts in a direction normal to the cutting force.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Tool Life: Wear and Failure”.

1. Crater wear occurs mainly on the

a) nose part, front relief face and side relief face of the cutting tool

b) face of the cutting tool at a short distance from the cutting edge only

c) cutting edge only

d) front face only

Answer: b

Explanation: Crater wear occurs on the rake face of the tool, while flank wear occurs on the relief  face of the tool.

2. Flank wear depends upon the

a) hardness of the work and tool material at the operating temperature

b) amount and distribution of hard constituents in the work material

c) degree of strain hardening in the chip

d) none of the mentioned

Answer: b

Explanation: Flank wear occurs as a result of friction between the progressively increasing contact area on the tool flank.

3. Crater wear is predominant in

a) carbon steels

b) tungsten carbide tools

c) high speed steel tools

d) ceramic tools

Answer: b

Explanation: Crater wear is usually found while machining brittle materials and tungsten carbide tools favour this phenomenon.

4. Flank wear is due to the abrasive action of hard mis-constituents.

a) True

b) False

Answer: a

Explanation: Flank wear is due to the abrasive action of hard mis-constituents including debris from built up edge as the work material rubs the work surface.

5. Crater wear is mainly due to the phenomenon is known as

a) adhesion of metals

b) oxidation of metals

c) diffusion of metals

d) none of the mentioned

Answer: c

Explanation: Flank wear is due to the abrasive action and crater wear is due to diffusion of metals.

6. Crater wear leads to

a) increase in cutting temperature

b) weakening of tool

c) friction and cutting forces

d) all of the mentioned

Answer: d

Explanation: None

7. Crater wear is usually found while machining ductile materials.

a) True

b) False

Answer: b

Explanation: Crater wear is usually found while machining brittle materials.

8. The tool may fail due to

a) cracking at the cutting edge due to thermal stresses

b) chipping of the cutting edge

c) plastic deformation of the cutting edge

d) all of the mentioned

Answer: d

Explanation: None

9. Flank wear occurs mainly on the

a) nose part, front relief face and side relief face of the cutting tool

b) face of the cutting tool at a short distance from the cutting edge only

c) cutting edge only

d) front face only

Answer: a

Explanation: Crater wear occurs on the rake face of the tool, while flank wear occurs on the relief  face of the tool.

10. Tool life is measured by the

a) number of pieces machined between tool sharpenings

b) time the tool is in contact with the job

c) volume of material removed between tool sharpenings

d) all of the mentioned

Answer: d

Explanation: None

11. The tool life is said to be over if

a) poor surface finish is obtained

b) there is sudden increase in cutting forces and power consumption

c) overheating and fuming due to heat of friction starts

d) all of the mentioned

Answer: d

Explanation: None

12. Tool life is generally better when

a) grain size of the metal is large

b) grain size of the metal is small

c) hard constituents are present in the micro structure of the tool material

d) none of the mentioned

Answer: a

Explanation: None

13. The relation between the tool life in minutes and cutting speed  in m/min is

a) V n T = C

b) VT n = C

c) V n /T = C

d) V/T n = C

Answer: b

Explanation: None

14. Using the Taylor Equation for tool life and letting n = 0.5 and C = 120, calculate the percentage increase in tool life when the cutting speed is reduced by 50%.

a) 100%

b) 200%

c) 300%

d) 400%

Answer: c

Explanation: Since n = 0.5, the Taylor equation can be rewritten as VT 0.5 = 120.

Let’s denote V 1 as the initial speed and V 2 the reduced speed; thus, V 2 = 0.5 V 1 . Because C is the constant 120, we have the relationship

0.5V 1 sqrt T 2 = V 1 sqrt T 1

Simplifying this equation, T 2 /T 1 = 1/0.25 = 4. This

indicates that the change in tool life is

(T 2 – T 1 / T 1 ) = (T 2 /T 1 ) – 1 = 4 – 1 = 3,

or that tool life is increased by 300%. Thus, a reduction in cutting speed has resulted in a major increase in tool life. Note also that, for this problem, the magnitude of C is not relevant.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Machinability”.

1. The specific cutting energy used for establishing the machinability of the metal depends upon its

a) coefficient of friction

b) micro-structure

c) work hardening characteristics

d) all of the mentioned

Answer: d

Explanation: None

2. For machining a mild steel workpiece using carbide tool, the maximum material will be removed at a temperature of

a) 50 0

b) 100 0

c) 175 0

d) 275 0

Answer: b

Explanation: None

3. For machining a mild steel workpiece by a high speed steel tool, the average cutting speed is

a) 5 m/min

b) 10 m/ min

c) 15 m/min

d) 30 m/min

Answer: d

Explanation: For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is 22 m/min and for a mild steel is 30 m/min.

4. For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is

a) 10 m/min

b) 15 m/min

c) 22 m/min

d) 30 m/min

Answer: c

Explanation: For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is 22 m/min and for a mild steel is 30 m/min.

5. The machining of titanium is difficult due to

a) high thermal conductivity of titanium

b) chemical reaction between tool and work

c) low tool-chip contact area

d) none of the mentioned

Answer: c

Explanation: None

6. The factor considered for evaluation of maintainability is

a) cutting forces and power consumption

b) tool life

c) type of chips and shear angle

d) all of the mentioned

Answer: d

Explanation: None

7. In machining metals, chips break due to _____________ of work material.

a) toughness

b) ductility

c) elasticity

d) work hardening

Answer: d

Explanation: None

8. In machining metals, surface roughness is due to

a) feed marks or ridges left by the cutting tool

b) fragment of built up edge on the machined surface

c) cutting tool vibrations

d) all of the mentioned

Answer: d

Explanation: None

9. In machining soft materials, a tool with a negative relief angle is used

a) True

b) False

Answer: a

Explanation: None

Answer: d

Explanation: None

Sanfoundry Global Education & Learning Series – Manufacturing Engineering.

This set of Manufacturing Engineering quiz focuses on “Cutting Tool Materials”.

1. The various cutting tool materials used are:

a) high speed steels

b) cast cobalt alloys

c) carbides

d) all of the mentioned

Answer: d

Explanation: Materials used for cutting tools are

a) high speed steels

b) cast cobalt alloys

c) carbides

d) coated tools

e) alumina-based ceramics

f) cubic boron nitride

g) silicon nitride based ceramics

h) diamond

i) whisker reinforced materials and nano materials

2. High speed steels are suitable for making

a) high positive rake angle tools

b) interrupted cuts

c) machine tools with ow stiffness that are subject to vibration

d) all of the mentioned

Answer: d

Explanation: Because of their toughness , high-speed steels are suitable especially for  high positive rake-angle tools ,  interrupted cuts,  machine tools with low stiffness that are subject to vibration and chatter, and  complex and single-piece tools, such as drills, reamers, taps, and gear cutters.

3. ___________ improves toughness, wear resistance, and high temperature strength.

a) Chromium

b) vanadium

c) Tungsten

d) None of the mentioned

Answer: a

Explanation: Chromium improves toughness, wear resistance, and high-temperature strength. Vanadium improves toughness, abrasion resistance, and hot hardness.

Tungsten and cobalt have similar effects, namely, improved strength and hot hardness.

Molybdenum improves wear resistance, toughness, and high-temperature strength and hardness.

4. _____________ contains nickel molybdenum matrix.

a) Chromium

b) Titanium carbide

c) Tungsten

d) None of the mentioned

Answer: b

Explanation: Titanium carbide  consists of a nickel-molybdenum matrix. It has higher Wear resistance than tungsten carbide but is not as tough. Titanium carbide is suitable for machining hard materials  and for cutting at speeds higher than those appropriate for tungsten carbide.

5. Coating materials used are

a) titaniun nitride

b) titanium carbide

c) titanium carbonitride

d) all of the mentioned

Answer: d

Explanation: Commonly used coating materials are titanium nitride , titanium carbide , titanium carbonitride , and aluminum oxide (Al 2 O 3 ).

6. Characteristics of coated cutting tools are:

a) high hardness

b) chemical stability

c) low thermal conductivity

d) all of the mentioned

Answer: d

Explanation: Coatings for cutting tools and dies should have the following general characteristics:

-> High hardness at elevated temperatures, to resist wear.

-> Chemical stability and inertness to the workpiece material, to reduce wear.

-> Low thermal conductivity, to prevent temperature rise in the substrate.

-> Compatibility and good bonding to the substrate, to prevent flaking or spalling.

-> Little or no porosity in the coating, to maintain its integrity and strength.

7. Ceramic tools are fixed to a tool body by ___________

a) soldering

b) brazing

c) welding

d) clamping

Answer: b

Explanation: The ceramic tools are fixed to a tool body by brazing. These tools have greater tool life than carbide tools.

8. The carbide tools operating at very low cutting speeds

a) reduces tool life

b) increases tool life

c) have no effect on tool life

d) spoils the work piece

Answer: a

Explanation: The carbide tools operating at very low cutting speeds below 30m/min reduces tool life.

9. High speed steel tools retain their hardness upto a temperature of

a) 250 0

b) 350 0

c) 500 0

d) 900 0

Answer: d

Explanation: None

10. The trade name of a non ferrous cast alloy composed of cobalt, chromium and tungsten is called

a) ceramic

b) stellite

c) diamond

d) cemented carbide

Answer: b

Explanation: None

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Cutting Fluids and Turning Process”.

1. In machining cast iron, no cutting fluid is required.

a) True

b) False

Answer: a

Explanation: None

2. The cutting fluid mostly used for machining alloy steels is :

a) water

b) soluble oil

c) dry

d) sulphurised mineral oil

Answer: d

Explanation: None

3. Cutting fluids are used to:

a) cool the tool

b) improve surface finish

c) cool the workpiece

d) all of the mentioned

Answer: d

Explanation: Functions of cutting fluids are

a) to cool the cutting tool and the workpiece

b) to lubricate the chip, tool and workpiece

c) to help carry away the chips

d) to lubricate some of the moving parts of the machine tool

e) to improve the surface finish

f) to prevent the formation of built up ridge

g) to protect the work against rusting

4. The cutting fluid mostly used for machining steel is:

a) water

b) soluble oil

c) dry

d) heavy oils

Answer: b

Explanation: Soluble oils are used for machining metals of high machinability.

5. Functions of cutting fluids are

a) to cool the cutting tool and the workpiece

b) to lubricate the chip, tool and workpiece

c) to help carry away the chips

d) all of the mentioned

Answer: d

Explanation: Functions of cutting fluids are

a) to cool the cutting tool and the workpiece

b) to lubricate the chip, tool and workpiece

c) to help carry away the chips

d) to lubricate some of the moving parts of the machine tool

e) to improve the surface finish

f) to prevent the formation of built up ridge

g) to protect the work against rusting

6. ______________ form mixtures ranging from emulsions to solutions.

a) Water miscible fluids

b) Neat oils

c) Synthetics

d) None of the mentioned

Answer: a

Explanation: Water miscible fluids form mixtures ranging from emulsions to solutions, which due to their high specific heat, high thermal conductivity, and high heat of vaporisation, are used on about 90% of all metal cutting and grinding operations.

7. Advantages of chemical fluids are

a) a very light residual film that is easy to remove

b) heat dissipation is rapid

c) good detergent properties

d) all of the mentioned

Answer: d

Explanation: Advantages of chemical fluids are

a) a very light residual film that is easy to remove

b) heat dissipation is rapid

c) good detergent properties

d) an easy concentration to control with no interference from tramp oils

8. The methods of application of cutting fluids are

a) flooding

b) jet application

c) mist application

d) all of the mentioned

Answer: d

Explanation: None.

9. In _____________ a high volume flow of the cutting fluid is generally applied on the back of the chip.

a) flooding

b) jet application

c) mist application

d) all of the mentioned

Answer: a

Explanation: In flooding, a high volume flow of the cutting fluid is generally applied on the back of the chip while in a jet application the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.

10. In _________ the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.

a) flooding

b) jet application

c) mist application

d) all of the mentioned

Answer: b

Explanation: In flooding, a high volume flow of the cutting fluid is generally applied on the back of the chip while in jet application the cutting fluid, which may be either a liquid or a gas is applied in the form of a fine jet under pressure.

11. ______________ controls both direction of chip flow and the strength of the tool tip.

a) Side rake angle

b) Relief angle

c) Rake angle

d) None of the mentioned

Answer: c

Explanation: Rake angle is important in controlling both the direction of chip flow and the strength of the tool tip.

12. _______________ acts downward on the tool tip.

a) Cutting force

b) Radial force

c) Thrust force

d) None of the mentioned

Answer: a

Explanation: The cutting force, F C , acts downward on the tool tip and thus tends to deflect the tool downward and the workpiece upward. The cutting force supplies the energy required for the cutting operation.

13. _________ acts in the longitudinal direction.

a) Cutting force

b) Radial force

c) Thrust force

d) None of the mentioned

Answer: c

Explanation: The thrust force, F t , acts in the longitudinal direction. It also is called the feed force, because it is in the feed direction of the tool.

14. ____________ acts in the radial direction.

a) Cutting force

b) Radial force

c) Thrust force

d) None of the mentioned

Answer: b

Explanation: The radial force, F r , acts in the radial direction and tends to push the tool away from the workpiece.

15. For turning a small taper on a long workpiece, the suitable method is

a) by a form tool

b) by setting over the tail stock

c) by a taper turning attachment

d) none of the mentioned

Answer: b

Explanation: None

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction to Lathe”.

1. End of the work piece can be supported by using

a) Headstock

b) Tailstock

c) Tool Post

d) None of the mentioned

Answer: b

Explanation: Tailstock is used to support the end of the work piece in a lathe machine.

2. Which of the following position of tumbler gear lever set will move carriage towards headstock of the lathe?

a) Up

b) Middle

c) Down

d) None of the mentioned

Answer: a

Explanation: Tumbler gear lever in up position moves the carriage towards the headstock in a lathe machine.

3. Which of the following can be used to reverse the direction of lead screw relative to the direction of spindle movement?

a) Speed lever

b) Feed Lever

c) Tumbler gear lever

d) Friction clutch

Answer: c

Explanation: Tumbler gear lever is used to reverse the direction of lead screw relative to the direction of spindle movement in lathe machine.

4. Which of the following arrangement is used in the movement of carriage along the ways?

a) Rack and pinion

b) Spindle mechanism

c) Crank and slotted lever mechanism

d) None of the mentioned

Answer: a

Explanation: Rack and pinion mechanism is used in movement of carriage by flywheel. Rack is gear of finite diameter.

5. Which of the following have a live centre?

a) Tail stock

b) Headstock

c) Tool post

d) None of the mentioned

Answer: b

Explanation: Head stock has live centre and it is called live because spindle rotates here and is not at rest during machining.

6. Which of the following is also known as Puppet head?

a) Headstock

b) Tailstock

c) Tool Post

d) None of the mentioned

Answer: b

Explanation: Tailstock is also known as puppet head. It is at the back part of lathe machine.

7. Which of the following part of lathe slides along bed ways?

a) Cross slide

b) Saddle

c) Compound rest

d) None of the mentioned

Answer: b

Explanation: Saddle slides along bed ways in lathe machine during the process of machining.

8. Which of the following part of lathe move in a direction normal to the axis of spindle?

a) Cross slide

b) Saddle

c) Compound rest

d) None of the mentioned

Answer: a

Explanation: Cross slide move in a direction normal to the axis of spindle during the process of machining in lathe machine.

9. Which of the following is used to give power feed during cutting of threads?

a) Rack and pinion

b) Planer mechanism

c) Quick return mechanism

d) Using spilt nut

Answer: d

Explanation: Split nut are used to engage lead screw to give power feed in lathe during the process of machining in lathe machine.

10. Which of the following serves as a housing for driving pulley, and back gears?

a) Headstock

b) Tailstock

c) Tool Post

d) None of the mentioned

Answer: b

Explanation: Headstock has driving pulleys and back gears in lathe machine. Headstock also carries spindle and chuck for holding the work piece.

11. The tail stock set over required to turn a taper on the entire length of a workpiece having diameters D and d is

a) D – d/2L

b) D – d/L

c) D – d/2

d) D – d

Answer: b

Explanation: None

12. For turning internal tapers, the suitable method is

a) by a form tool

b) by setting over the tail stock

c) by a taper turning attachment

d) none of the mentioned

Answer: c

Explanation: None

13. The tail stock set over method of taper turning is preferred for

a) internal tapers

b) small tapers

c) long slender tapers

d) steep tapers

Answer: c

Explanation: None

This set of Manufacturing Engineering MCQs focuses on “Lathe-1”.

1. Which of the following is correct about series of range of speed in simple lathe?

a) Geometric progression

b) Arithmetic progression

c) Logarithmic progression

d) Harmonic progression

Answer: a

Explanation: Geometric progression is the series of numbers having a common ratio. Range of speed follow geometric progression in simple lathe.

2. Which of the following is the correct basis in designing feed gear box for screw cutting?

a) Geometric progression

b) Arithmetic progression

c) Logarithmic progression

d) Harmonic progression

Answer: a

Explanation: Geometric progression is the series of numbers having a common ratio. Feed gears box have ranges following geometric progression.

3. If cutting tool travel 1000mm in the direction of feed motion with work piece rotational speed of 500 rpm and feed rate of 0.2mm/rev, machining time in minutes will be

a) 2

b) 6

c) 8

d) 10

Answer: d

Explanation: Use t=L/ FN) where ‘t’ is time, ”L’ is effective length, ‘F’ is feed and ‘N’ is number of revolution per second.

4. Facing of work piece of diameter 72mm is need to be done at spindle speed of 80 rev per min at cross feed of 0.3mm/rev. The time required in minute for facing operation will be

a) 2

b) 1.5

c) 2.5

d) 3

Answer: b

Explanation: Time required for machining is given by, t=L/ FN) where ‘t’ is time, ”L’ is effective length, ‘F’ is feed and ‘N’ is number of revolution per second.

5. Compound rest swiveling method in taper turning operation is most suitable for

a) Long jobs with small taper angles

b) Short jobs with small taper angles

c) Short jobs with steep taper angles

d) Long jobs with steep taper angles

Answer: c

Explanation: Compound rest swiveling method gives less space and less revolution and hence in taper turning operation it is most suitable for Short jobs with steep taper angles.

6. In which of the following, tail stock method of taper turning operation will be preferred more?

a) Internal tapers

b) Steep tapers

c) Small tapers

d) Long slender tapers

Answer: d

Explanation: For long slender tapers, tail stock over method is most suitable because tail stock method gives large space and large taper angle also.

7. Which of the followings is the correct type of threads used in lead screw having half nut in the lathe which is free to rotate in both directions?

a) ACME threads

b) Buttress threads

c) Whitworth threads

d) V‐threads

Answer: a

Explanation: ACME threads have greater efficiency than other profiles of threads and hence are used in lead screw.

8. Which of the following is used to produce quality screw threads?

a) Thread casting

b) Thread cutting with single point tool

c) Thread milling ad cutting with single point tool

d) Thread chasing

Answer: d

Explanation: Quality screw threads are produced by using thread chasing, which is a very precise operation.

9. Which of the following can produce both external as well as internal threads?

a) Die threading with self‐opening die heads

b) Thread tapping with taps

c) Thread milling and multiple‐thread cutters

d) Thread chasing with multiple‐rib chasers

Answer: c

Explanation: Thread milling and multiple thread cutters are generally used for the production of internal and external threads.

10. In surface finishing operation one should use a sharp tool with a ______ feed and _______ Speed of rotation of the job.

a) Minimum, minimum

b) Minimum, maximum

c) Maximum, maximum

d) Maximum, minimum

Answer: b

Explanation: Minimum feed and maximum speed of rotation gives very small material removal rate and hence used for surface finishing operation.

This set of Manufacturing Engineering Multiple Choice Questions & Answers focuses on “Lathe-2”.

1. Which of the following is the correct reason for keeping transverse force minimum in turning of slender rod?

a) To enhances surface finish

b) To increase productivity

c) To increase efficiency of cutting

d) To reduce undesired vibration during turning

Answer: d

Explanation: Vibration is the major problem during turning of slandered rod due to which it is advised to keep transverse force minimum during turning of slender rod.

2. Self centered chuck has ___ number of jaws.

a) 10

b) 1

c) 2

d) 3

Answer: d

Explanation: 3-jaw chucks are also known as self centered chuck, hence they have 3 jaws.

3. During groove cutting in a lathe, by using a parting tool, which of the following forces are encountered?

a) Tangential

b) Radial

c) Tangential, Radial and Axial

d) Tangential and Radial

Answer: c

Explanation: Radial, axial and tangential forces are encountered during groove cutting on a lathe machine.

4. Which of the following will give the best result for taper turning on the internal surface?

a) Using tailstock offset method

b) Using taper attachment method

c) Using form tool

d) Using compound rest method

Answer: d

Explanation: Compound rest method is generally used for taper turning on internal surfaces.

5. Lead screw of lathe have double start thread with a pitch of 4mm. What should be the ratio of speed between lead screw and spindle for producing a single start thread of 2 mm pitch?

a) 1:2

b) 1:3

c) 1:4

d) 1:5

Answer: c

Explanation: Number of starts and pitch of lathe is directly proportional to speed of spindle required.

6. Let screw of 2mm pitch is needed to be cut on lathe machine. Lead screw of lathe has pitch of 6mm. Which of the following statement is correct?

a) Speed of lead screw> speed of spindle

b) Speed of lead screw< speed of spindle

c) Speed of lead screw=speed of spindle

d) None of the mentioned

Answer: b

Explanation: Speed of lead screw decreases in relative to speed of spindle as many times the required pitch is larger than pitch of lead screw.

7. Speed of lead screw decreases in relative to speed of spindle as many times the required pitch is larger than pitch of lead screw.

a) True

b) False

Answer: a

Explanation: Lead screw will move axially equal to pitch of lead screw after one complete rotation of lead screw.

8. Speed of lead screw decreases in relative to speed of spindle as many times the required pitch is smaller than pitch of lead screw.

a) True

b) False

Answer: b

Explanation: Lead screw will move axially equal to pitch of lead screw after one complete rotation of lead screw.

9. What are thread chasers?

a) Multipoint cutting tool

b) Single point cutting tool

c) A work holding device

d) None of the mentioned

Answer: a

Explanation: Thread chasers are multipoint cutting tool used for cutting threads.

10. Total load is distributed over all teeth when thread cutting is done using thread chaser.

a) True

b) False

Answer: a

Explanation: Distribution of load over all teeth is the main advantage of using thread chaser for thread cutting operation.

This set of Manufacturing Engineering online test focuses on “Lathe-3”.

1. Which of the following can be effectively used for holding eccentric job?

a) Four jaw chuck

b) Three jaw chuck

c) Both three jaw chuck and four jaw chuck

d) Two jaw chuck

Answer: a

Explanation: Four jaw chucks are used for holding eccentric job because of good manual balancing capability of four jaws.

2. Which of the following can be effectively used for holding irregular job?

a) Four jaw chuck

b) Three jaw chuck

c) Both three jaw chuck and four jaw chuck

d) Two jaw chuck

Answer: a

Explanation: Four jaw chucks are used for holding irregular job because of good manual balancing capability of four jaws.

3. Which of the following is also known as universal chuck?

a) Four jaw chuck

b) Three jaw chuck

c) Both three jaw chuck and four jaw chuck

d) Two jaw chuck

Answer: a

Explanation: Four jaw chucks are used for holding eccentric job as well as irregular job apart from holding symmetric job because of good manual balancing capability of four jaws.

4. Which of the following is mostly used for holding bored part of the job?

a) Mandrels

b) Dogs

c) Collet

d) Angle plate

Answer: a

Explanation: Mandrels are used to hold bored job during machining process of jobs.

5. What will be the value of half taper angle in degrees if diameter of big end is 100mm and diameter of small end is 60mm for a 1m long job?

a) 3.19

b) 5.29

c) 1.14

d) 2.29

Answer: c

Explanation: Half angle can be calculated by using- tan  = / .

6. What will be the value of half taper angle in degrees if diameter of big end is 500mm and diameter of small end is 60mm for a 1m long job?

a) 31.10

b) 52.30

c) 31.10

d) 12.40

Answer: d

Explanation: Half angle can be calculated using- tan  = / .

7. What will be the value of diameter of big end in mm for tapered job if diameter of small end and length of job is 60mm and 1m respectively? Given half taper angle is equal to 12.4 degrees.

a) 600

b) 500

c) 400

d) 300

Answer: b

Explanation: Big end diameter can be calculated using- tan  = / .

8. What will be the value of diameter of small end in mm for tapered job if diameter of big end and length of job is 60mm and 1m respectively? Given half taper angle is equal to 1.14 degrees.

a) 600

b) 200

c) 100

d) 300

Answer: c

Explanation: Small end diameter can be calculated using- tan  = / .

9. During taper turning operation 100mm of smaller side diameter and 800mm of bigger side diameter was required. What will be the value of taper gradient for a job of 1m in length?

a) 15.01

b) 19.29

c) 28.35

d) 56.31

Answer: b

Explanation: Taper gradient= tan  = / .

10. During taper turning operation 100mm of smaller side diameter and 800mm of bigger side diameter was required. What will be the value of Conicity for a job of 1m in length?

a) 31.20

b) 23.20

c) 56.32

d) 38.58

Answer: d

Explanation: Conicity=2* tan  = / .

This set of Manufacturing Engineering online quiz focuses on “Lathe-4”.

1. What will be the length of job in m if diameter of big end is 100mm and diameter of small end is 60mm for a taper angle of 1.14 degree?

a) 5

b) 2

c) 7

d) 1

Answer: d

Explanation: Length be calculated by using- tan  = /  where ‘D’ is the external diamter, ‘d’ is the internal diameter, ‘L’ is the length of the job.

2. The job of total length 300mm is tapered turned on lathe using tailstock set over method. The two diameters obtained are 80mm and 500mm and length of taper was 200mm only. Tail stock set over is equal to

a) 10

b) 15

c) 20

d) 25

Answer: b

Explanation: Tail stock set over= L*/ , where ‘D’ is the external diameter, ‘d’ is the internal diameter, ‘L’ is the length of job.

3. A job of total length 800mm is tapered turned on lathe using tailstock set over method. The two diameters obtained are 450mm and 500mm and length of taper was 700mm only. Tail stock set over is equal to

a) 10.12

b) 15.32

c) 20.32

d) 28.57

Answer: d

Explanation: Tail stock set over= L*/ , where ‘D’ is the external diameter, ‘d’ is the internal diameter, ‘L’ is the length of job.

4. A cast iron piece of total length 100mm is needed to be tapered for a length of 40mm using swiveling the compound rest method. Diameter of job is 20mm and smaller end have nearly zero diameter. What should the angle in degrees by which compound rest should be rotated?

a) 20.36

b) 45.21

c) 14.03

d) 5.23

Answer: c

Explanation: tan  = / , where ‘D’ is the external diameter, ‘d’ is the internal diameter, ‘L’ is the length of job.

5. Distance measured normal to the axis of part, between crest and root of thread is known as

a) Pitch

b) Depth of threads

c) Thread angle

d) Major diameter

Answer: b

Explanation: Depth of threads is the distance measured normal to the axis of a part, between crest and root of thread.

6. Distance from one point of thread to the next corresponding point is known as

a) Pitch

b) Depth of threads

c) Thread angle

d) Major diameter

Answer: b

Explanation: Pitch is the distance from one point of thread to the next corresponding point.

7. If the nut rotated in clockwise direction and advances axially, then threads present in nut are

a) Right Handed threaded

b) left handed thread

c) Right handed and left handed both

d) None of the mentioned

Answer: a

Explanation: In right handed thread nut rotated in clockwise direction and advances axially where as its reverse takes place in left handed threads.

8. Lead of nut is 2mm and has double start threads. What is the pitch of nut?

a) 1

b) 2

c) 3

d) 6

Answer: a

Explanation: Pitch=lead/number of starts.

9. A thread has number of starts equal to one. Which of the following is most correct about thread?

a) Pitch > lead

b) Pitch<<lead

c) Pitch < lead

d) Pitch=lead

Answer: d

Explanation: Pitch=lead/number of starts.

10. Let screw of 10mm pitch is needed to be cut on lathe machine. Lead screw of lathe has pitch of 6mm. Which of the following statement is correct?

a) Speed of lead screw is greater than speed of spindle

b) Speed of lead screw is less that speed of spindle

c) Speed of lead screw is equal to speed of spindle

d) None of the mentioned

Answer: a

Explanation: Speed of lead screw increase in relative to speed of spindle as many times the required pitch is smaller than pitch of lead screw.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Capstan and Turret Lathe”.

1. Which of the following lathe requires very high skills for operation?

a) Centre lathe

b) Capstan lathe

c) Turret lathe

d) All of the mentioned

Answer: a

Explanation: Centre lathe is much more typical than other lathe machines and hence requires much more skills.

2. Which of the following have the lowest degree of automation?

a) Centre lathe

b) Capstan lathe

c) Turret lathe

d) All of the mentioned

Answer: a

Explanation: Centre lathe has a nominal degree of automation. Most of the operation is done manually and are not automatic.

3. Which of the following requires high labor cost?

a) Turret lathe

b) Capstan lathe

c) Centre lathe

d) All of the mentioned

Answer: c

Explanation: Centre lathe requires high labor cost because it requires good skills for performing operations on it.

4. Which of the following offers minimum overhead charge?

a) Turret lathe

b) Capstan lathe

c) Centre lathe

d) All of the mentioned

Answer: c

Explanation: Centre lathe requires low overhead charges due to small initial investment and low maintenance.

5. Which of the following lathe is most versatile?

a) Turret lathe

b) Capstan lathe

c) Centre lathe

d) All of the mentioned

Answer: c

Explanation: Centre lathe is capable of handling varying shape jobs and hence is most versatile.

6. Turret head in turret lathe is generally mounted on

a) Slide

b) Saddle

c) Ram

d) None of the mentioned

Answer: b

Explanation: Turret head is one of the important feature of turret lathe generally mounted on saddle.

7. Lead crew is present in turret lathe for thread cutting

a) True

b) False

Answer: b

Explanation: Thread cutting in turret lathe is generally produced by taps and die heads, hence lead screw are not present in turret lathe.

8. Lead crew is present in Capstan lathe for thread cutting

a) True

b) False

Answer: b

Explanation: Thread cutting in turret lathe is generally produced by taps and die heads, hence lead screw are not present in Capstan lathe.

9. Which of the following is not much effective for mass production i.e. production of same types of job?

a) Turret lathe

b) Capstan lathe

c) Centre lathe

d) All of the mentioned

Answer: c

Explanation: Centre lathe have a low degree of automation and is good in versatile jobs production.

10. Which of the following lathe requires low maintenance?

a) Turret lathe

b) Capstan lathe

c) Centre lathe

d) All of the mentioned

Answer: c

Explanation: Turret and capstan have a large number of parts, hence require large amount of maintenance.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Shaper Parts”.

1. Cutting of material during shaping operation takes place in

a) Forward stroke

b) Backward stroke

c) Both forward and backward stroke

d) None of the mentioned

Answer: a

Explanation: Cutting always takes place in forward stroke. Backward stroke is ideal stroke.

2. Which of the following part of shaper supports all of the other parts of machines?

a) Base

b) Column

c) Cross rail

d) Table

Answer: a

Explanation: Base act as support for all other parts. It is made of stronger material.

3. Cutting of material during slotting operation takes place in

a) Forward stroke

b) Backward stroke

c) Both forward and backward stroke

d) None of the mentioned

Answer: a

Explanation: Cutting always takes place in forward stroke. Backward stroke is ideal stroke.

4. Which of the following act as housing for an operating mechanism in shaper?

a) Base

b) Column

c) Cross rail

d) Table

Answer: b

Explanation: Column acts as housing for operating mechanism in shaper. It is made of stronger material.

5. Which of the following part of shaper machine carries table elevating mechanism?

a) Base

b) Column

c) Cross rail

d) Table

Answer: c

Explanation: Cross rail carries table elevating mechanism. It is used to raise the height of the table.

6. Which of the following part of shaper machine carries vertical guide ways mechanism?

a) Base

b) Column

c) Cross rail

d) Table

Answer: c

Explanation: Cross rail carries vertical guide ways mechanism. Cross rail carries table elevating mechanism. It is used to raise the height of table.

7. Which of the following part of shaper machine hold and supports the work piece?

a) Base

b) Column

c) Cross rail

d) Table

Answer: d

Explanation: Table supports work piece. It is made of harder material.

8. Which of the following part of shaper machine carries tool head?

a) Cross rail

b) Column

c) Ram

d) Table

Answer: c

Explanation: Ram carries tool head. It also carries mechanism for tool head movement.

9. Which of the following part of shaper provides straight line motion of tool?

a) Cross rail

b) Column

c) Ram

d) Table

Answer: c

Explanation: Ram carries tool head and provides straight line motion to a tool.

10. Which of the following part of shape is used to hold the tool?

a) Cross rail

b) Tool head

c) Ram

d) Vice

Answer: b

Explanation: Tool head is used for tool holding purpose. It is attached to ram.

11. Which of the following can be used as job holding device in shaping machine?

a) Cross rail

b) Column

c) Ram

d) Vice

Answer: d

Explanation: Vice is a job holding device. It have good efficiency as holding device.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Shaper Mechanism”.

1. Which of the following shaper machine cuts in return stroke?

a) Vertical shaper

b) Horizontal shaper

c) Draw cut shaper

d) Universal shaper

Answer: c

Explanation: Draw cut shaper cuts in the return stroke. While in general cutting takes place in forward stroke.

2. Slotted link of crank and slotted lever mechanism is also known as

a) Lever

b) Rocker

c) Crank

d) None of the mentioned

Answer: b

Explanation: As slotted arm does not make complete revolution during cutting, hence it is also known as rocker.

3. Slotted link of crank and slotted link mechanism is pivoted to

a) Fulcrum

b) Lever

c) Tool

d) None of the mentioned

Answer: a

Explanation: Slotted link is pivoted to fulcrum. Slotted arm does not make complete revolution during cutting.

4. Time of return stroke is ________ the time of forward stroke in crank and slotted link mechanism.

a) Less than

b) More than

c) Equal to

d) None of the mentioned

Answer: a

Explanation: of return stroke is less than the time of forward stroke in crank and slotted link mechanism. It reduces the time of idle stroke.

5. In crank and slotted link mechanism, cutting angle is 220 degrees. What should be the return stroke angle?

a) 12

b) 90

c) 140

d) 360

Answer: c

Explanation: Return stroke angle = 360 – cutting angle. Cutting takes place in forward stroke.

6. In a crank and slotted lever mechanism, length of fixed link and crank is 250 mm and 100 mm respectively. Inclination of slotted lever with vertical at extreme position in degrees is equal to

a) 25

b) 23.6

c) 28.3

d) 20

Answer: b

Explanation: Use simple geometry in a triangle. Return stroke angle = 360 – cutting angle.

7. In a crank and slotted lever mechanism, length of fixed link and crank is 250 mm and 100 mm respectively. Ratio of cutting stroke time to return stroke time will be

a) 5

b) 2.6

c) 1.7

d) 0

Answer: c

Explanation: Ratio of cutting stroke time to return stroke time = .

8. In a crank and slotted lever mechanism, length of fixed link and crank is 250 mm and 100 mm respectively. Cutting angle in degrees is equal to

a) 47.2

b) 12.3

c) 56

d) 69.3

Answer: a

Explanation: Use simple geometry in a triangle to find cutting angle.Return stroke angle = 360 – cutting angle.

9. In a crank and slotted lever mechanism, length of fixed link and crank is 250 mm and 100 mm respectively. Return angle in degrees is equal to

a) 147.2

b) 112.3

c) 156

d) 132.8

Answer: d

Explanation: Use simple geometry in a triangle to find cutting angle. Return stroke angle = 360 – cutting angle.

10. In a crank and slotted lever mechanism, length of fixed link and crank is 250 mm and 100 mm respectively. Length of stroke in mm will be

a) 447.2

b) 312.3

c) 56

d) 360.3

Answer: d

Explanation: Use simple geometry in a triangle to find cutting angle. Return stroke angle = 360 – cutting angle. Cutting angle = 47.2 degree.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Slotter”.

1. Cutting of material during slotting operation takes place in

a) Forward stroke

b) Backward stroke

c) Both forward and backward stroke

d) None of the mentioned

Answer: a

Explanation: Cutting always takes place in forward stroke. Backward stroke is an ideal stroke.

2. Which of the following part of slotting machine supports all of the other parts of machines?

a) Base

b) Column

c) Ram

d) Table

Answer: a

Explanation: Base act as support for all other parts and hence it is made strong.

3. Cutting of material during shaping operation takes place in

a) Forward stroke

b) Backward stroke

c) Both forward and backward stroke

d) None of the mentioned

Answer: a

Explanation: Cutting always takes place in forward stroke. Backward stroke is ideal stroke.

4. Which of the following act as housing for an operating mechanism in slotting machine?

a) Base

b) Column

c) Cross rail

d) Table

Answer: b

Explanation: Column acts as housing for an operating mechanism in slotting machine and hence it is made of hard material.

5. Which of the following part of slotting machine carries table elevating mechanism?

a) Base

b) Column

c) Ram

d) Table

Answer: b

Explanation: Column carries table elevating mechanism. Column act housing for an operating mechanism in slotting machine and hence it is made of hard material.

6. Which of the following part of slotting machine carries vertical guide ways mechanism?

a) Base

b) Column

c) Cross rail

d) Table

Answer: b

Explanation: Column carries vertical guide ways mechanism. housing for operating mechanism in slotting machine and hence it is made of hard material.

7. Which of the following part of slotting machine hold and supports the work piece?

a) Base

b) Column

c) Cross rail

d) Table

Answer: d

Explanation: Table supports work piece and its made of very hard material.

8. Which of the following part of slotting machine carries tool head?

a) Cross rail

b) Column

c) Ram

d) Table

Answer: c

Explanation: Ram carries tool head. It is present on the upper part of machines.

9. Which of the following part of slotting machine provides straight line motion of tool?

a) Cross rail

b) Column

c) Ram

d) Table

Answer: c

Explanation: Ram carries tool head and provides straight line motion to a tool. There is kinematic straight line mechanism in ram.

10. Which of the following part of slotting machine is used to hold the tool?

a) Cross rail

b) Tool head

c) Ram

d) Vice

Answer: b

Explanation: Tool head is used for tool holding purpose. Different types of tool head used to hold different types of workpiece.

11. Which of the following can be used as job holding device in slotting machine?

a) Cross rail

b) Column

c) Ram

d) Vice

Answer: d

Explanation: Vice is a job holding device. It is holding a device with good efficiency.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction to Milling”.

1. Which of the following act as load bearing part of milling machine?

a) Base

b) Column

c) Knee

d) Table

Answer: a

Explanation: Base act as support in milling machine. It is made of very strong material and have good surface hardness.

2. Knee of milling machine is attached and slides up and down on

a) Base

b) Column

c) Knee

d) Table

Answer: a

Explanation: Knee slide over column. Column has motor drive attached to its rear side. Base can be used as reservoir for coolant.

3. Motor drive in milling machine is generally attached to

a) Base

b) Column

c) Knee

d) Table

Answer: b

Explanation: Column has the motor drive attached to its rear side. Base can be used as a reservoir for coolant. Knee slide over column.

4. Which of the following part of milling machine can be used for reservoir for coolant?

a) Base

b) Column

c) Knee

d) Table

Answer: a

Explanation: Base can be used as reservoir for coolant. Knee slide up and down on column.

5. Which of the following is capable of sliding up and down in milling machines?

a) Base

b) Column

c) Knee

d) Table

Answer: c

Explanation: Knee slide up and down on column. Knee adjusts table height by sliding up and down on a milling machine.

6. Which of the following part movement of milling machines helps in adjustment of table height?

a) Base

b) Column

c) Knee

d) Table

Answer: c

Explanation: Knee adjusts table height by sliding up and down on a milling machine. Knee slide up and down on column.

7. Which of the following part of the milling machine is used to support work piece?

a) Base

b) Column

c) Knee

d) Table

Answer: d

Explanation: Table is used to support work piece. Cast iron has very good surface hardness and hence used for table of milling machine.

8. Table of milling machine is generally made up of

a) Cast iron

b) Steel

c) Aluminum

d) None of the mentioned

Answer: a

Explanation: Cast iron has very good surface hardness and hence used for table of milling machine. Table is used to support work piece.

9. Which of the following carries clamping bolt T-slots for fixing work piece?

a) Base

b) Column

c) Knee

d) Table

Answer: a

Explanation: Table is used to work piece and hence has T slots for clamping bolts. Cast iron has very good surface hardness and hence used for the table of milling machine. Table is used to support work piece.

10. Which of the following is the heavy support provided at the top of both plain and universal milling machine?

a) Base

b) Over arm

c) Knee

d) Table

Answer: b

Explanation: Over arm act as heavy support provided at the top. Table is used to support work piece. Base can be used as reservoir for coolant.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Milling Cutters”.

1. Which of the following milling cutters have teeth only on their periphery?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: a

Explanation: Plain milling cutters have teeth only on their periphery.

2. Which of the following milling cutters have teeth on their periphery as well as on their one side or both the side?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: b

Explanation: Side milling cutters have teeth on their periphery as well as on their one side or both the side. They can cut from both the sides.

3. Which of the following milling cutters have teeth on their periphery as well as on their end?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: c

Explanation: End milling cutters have teeth on their periphery as well as on their end. They are used in end milling or periphery milling.

4. Which of the following milling cutters have teeth on their periphery as well as on their end face?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: d

Explanation: Face milling cutters have teeth on their periphery as well as on their end face. They are used in face milling operations.

5. In face milling cutters, maximum cutting is done by the teeth on the periphery.

a) True

b) False

Answer: a

Explanation: Maximum cutting in face milling cutter is generally done by the teeth on its periphery.

6. In face milling cutters, teeth on end face perform a type of finishing operation during cutting.

a) True

b) False

Answer: a

Explanation: Maximum cutting in face milling cutter is generally done by the teeth on its periphery and teeth on end face generally perform finishing the operation.

7. Which of the following milling cutters can be used for cutting thin slots or for parting off operations?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Metal slitting cutters

Answer: d

Explanation: Metal slitting cutters can be used for cutting thin slots or for parting off operations.

8. Which of the following milling cutters can be used for formation of V-grooves?

a) Angle milling cutters

b) Form milling cutters

c) Gear cutters

d) Woodruff-key cutter

Answer: a

Explanation: As V is an angular shape, angle milling cutters can be used for the formation of V-grooves.

9. Woodruff Key milling cutter is a type of

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: c

Explanation: Woodruff Key milling cutter is a small type of End milling cutters. These are special types of cutters.

10. Which of the following milling cutter is capable of removable of large material with very small power consumption?

a) Plain milling cutters

b) Side milling cutters

c) End milling cutters

d) Face milling cutters

Answer: a

Explanation: Plain milling cutters have low power consumption but high material removal rate.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Milling Attachment”.

1. Arbors in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: a

Explanation: Arbors are standard attachments used to hold cutters. They are used in milling operation to hold the milling cutters.

2. Collets in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: a

Explanation: Collets are standard attachments and used to hold milling cutters. They are used in milling operation to hold the milling cutters.

3. Adaptors in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: a

Explanation: Adaptors are standard attachments and used to hold milling cutters. They are used in milling operation to hold the milling cutters.

4. Vice circular table in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: b

Explanation: Vice circular table are standard attachments and used to hold the work piece on table. They are used in milling operation to hold the workpiece.

5. Indexing head in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: b

Explanation: Indexing head are standard attachments and used to hold the work piece on table. They are used in milling operation to hold the workpiece.

6. Tailstock in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: b

Explanation: Tailstock is standard attachment and used to hold the work piece on table. They are used in milling operation to hold the milling cutters.

7. Spiral milling attachment in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: c

Explanation: Spiral milling attachment is standard attachment and acts as auxiliary spindle.

8. Vertical milling attachment in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: c

Explanation: Vertical milling attachment is standard attachment and acts as auxiliary spindle.

9. Slotting milling attachment in milling machines are generally used to

a) Hold cutters

b) Hold the work piece on table

c) Act as auxiliary spindle

d) None of the mentioned

Answer: c

Explanation: Slotting milling attachment is standard attachment and acts as auxiliary spindle.

10. Which of the following is not a standard milling attachment?

a) Arbors

b) Collets

c) Jigs and fixture

d) Adaptors

Answer: c

Explanation: Jigs and fixture are special attachments used in milling operations.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Milling Operations-1”.

1. Which of the following milling operation can be used for machining a flat surface, parallel to the axis of cutter?

a) Slab milling

b) Face milling

c) Angular milling

d) Form milling

Answer: a

Explanation: Slab milling operation can be used for machining a flat surface, parallel to the axis of cutter. It uses face cutters.

2. Which of the following milling operation can be used for machining of flat surface which is the right angle to the axis of cutter?

a) Slab milling

b) Face milling

c) Angular milling

d) Form milling

Answer: b

Explanation: Face milling operation can be used for machining a flat surface, perpendicular to the axis of cutter. It may use periphery cutters or face cutters.

3. Which of the following milling operation can be used for machining of flat surface which is at some angle to the axis of cutter?

a) Slab milling

b) Face milling

c) Angular milling

d) Form milling

Answer: c

Explanation: Angular milling operation can be used for machining a flat surface, which is at some angle to the axis of cutter.

4. Which of the following milling process is used for machining of irregular shapes?

a) Slab milling

b) Face milling

c) Angular milling

d) Form milling

Answer: d

Explanation: Form milling operation can be used for machining Irregular surface. It uses special form cutters.

5. Which of the following milling process is used for machining of two parallel vertical surface of a job simultaneously?

a) Key way milling

b) Groove milling

c) Gang milling

d) Straddle milling

Answer: d

Explanation: Straddle milling operation can be used for machining of two parallel vertical surface of a job simultaneously.

6. Which of the following milling process is used for machining of a number of flat horizontal and vertical surfaces simultaneously using more than two cutters at the same time mounted on common arbor?

a) Key way milling

b) Groove milling

c) Gang milling

d) Straddle milling

Answer: c

Explanation: Gang milling uses multiple cutters. All the cutter works simultaneously during the milling operation.

7. Which of the following milling operation can be used for producing grooves in work piece?

a) Key way milling

b) Groove milling

c) Gang milling

d) Straddle milling

Answer: b

Explanation: Groove milling can be used for producing grooves in work piece.

8. Which of the following operation can be used for parting of work piece in two pieces?

a) Key way milling

b) Groove milling

c) Saw milling

d) Straddle milling

Answer: c

Explanation: Saw milling can be used for parting off operations. It uses special milling cutters.

9. In which of the following milling cutters, power requirement will increase slightly?

a) Negative rake angle tool

b) Positive rake angle tool

c) Both positive and negative rake angle tool

d) None of the mentioned

Answer: b

Explanation: Power requirement for positive rake angle tool is generally more than negative rake angle tool.

10. Which of the following cutter can be used for finishing off previously milled slot?

a) Key way milling cutter

b) Dovetail milling cutter

c) Saw milling cutter

d) Slitting milling cutter

Answer: b

Explanation: Dovetail milling cutters are used for finishing previously milled slots.

This set of Manufacturing Engineering Question Bank focuses on “Milling Operations”.

1. Diameter of milling cutter is 100 mm, running at 210 rpm. Cutting speed in m/min is equal to

a) 26

b) 23

c) 66

d) 78

Answer: c

Explanation: V= /1000. V is the cutting speed, D is diameter and N is the revolution per minute.

2. Distance moved by table in mm in one minute in any direction is known as

a) Feed per minute

b) Feed per tooth

c) Feed per revolution

d) None of the mentioned

Answer: a

Explanation: Distance moved by table in mm in one minute in any direction is known as feed per minute.

3. Distance moved by a table in mm during time when cutter revolve through angle corresponding to distance between two cutting edges of two adjacent teeth is known as

a) Feed per minute

b) Feed per tooth

c) Feed per revolution

d) None of the mentioned

Answer: b

Explanation: Distance moved by a table in mm during time when cutter revolves through angle corresponding to distance between two cutting edges of two adjacent teeth is known as feed per tooth.

4. In a milling operation, feed per tooth is 0.020 mm and the total number of teeth on milling cutter is 50. Feed per revolution in mm is equal to

a) 0.2

b) 1.4

c) 1.0

d) 0.7

Answer: c

Explanation: Feed per revolution= feed per tooth * number of teeth.

5. In a milling operation, feed per revolution is 5 mm and the total number of teeth on milling cutter is 50. Feed per tooth in mm is equal to

a) 0.1

b) 0.2

c) 0.5

d) 0.05

Answer: a

Explanation: Feed per revolution= feed per tooth * number of teeth.

6. In a milling operation, feed per revolution is 0.05 mm and speed of 400 rpm. Feed per min in mm/min is equal to

a) 1

b) 2

c) 0.5

d) 0.05

Answer: b

Explanation: Feed per minute= feed per revolution* speed.

7. In a milling operation, feed per min is 10 mm and speed of 500 rpm. Feed per min in mm/min is equal to

a) 1

b) 2

c) 0.5

d) 0.04

Answer: d

Explanation: Feed per minute= feed per revolution* speed.

8. In a milling operation feed per tooth is .002 mm and number of teeth is 50 rotating with 60 rpm. Feed per min in mm/min is equal to

a) 3

b) 4

c) 6

d) None of the mentioned

Answer: c

Explanation: Feed per minute= feed per tooth* speed*number of teeth.

9. In a milling operation feed per tooth is .002 mm and number of teeth is 30 rotating with 40 rpm. Feed per min in mm/min is equal to

a) 3

b) 4.3

c) 2.4

d) None of the mentioned

Answer: c

Explanation: Feed per minute= feed per tooth* speed*number of teeth.

10. In a milling operation feed per revolution is 10 mm/rev and number of teeth is 50 rotating with 10 rpm. Feed per tooth in mm is equal to

a) .02

b) .04

c) .06

d) None of the mentioned

Answer: a

Explanation: Feed per minute= feed per tooth* speed*number of teeth.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Milling Methods”.

1. In which of the following milling method cutters rotate in direction opposite to that in which work is fed?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: a

Explanation: In up milling cutters rotate in the direction opposite to that in which work is fed.

2. In which of the following milling method chip thickness increase gradually?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: a

Explanation: In up milling chip thickness increase gradually whereas in down milling chip thickness decreases gradually.

3. In which of the following milling method chip thickness decrease gradually?

a) Up milling

b) Conventional milling

c) Down milling

d) None of the mentioned

Answer: c

Explanation: In down milling, chip thickness decreases gradually whereas in up milling chip thickness increase gradually.

4. In which of the following milling method chip thickness is nearly zero at the start of cut?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: a

Explanation: In up milling, chip thickness increases gradually from zero at the start of cut to the maximum value at the end.

5. In which of the following milling method chip thickness is maximum at the end of cut?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: a

Explanation: In up milling chip thickness increase gradually whereas in down milling chip thickness decreases gradually.

6. In which of the following milling method chip thickness is nearly zero at the end of cut?

a) Up milling

b) Conventional milling

c) Down milling

d) None of the mentioned

Answer: b

Explanation: In down milling chip thickness decrease gradually from maximum at the start of cut to the zero at the end.

7. Which of the following will result in best surface finish of job?

a) Up milling

b) Conventional milling

c) Down milling

d) None of the mentioned

Answer: c

Explanation: Down milling gives better surface finish than up milling. In down milling chip thickness decrease gradually from maximum at the start of cut to the zero at the end.

8. In which of the following methods work piece will have a tendency to be pulled up?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: a

Explanation: In up milling cutters rotate in the direction opposite to that in which work is fed. Upward force is acted on work piece by tool.

9. In which of the following methods of milling there would be less radial pressure on the arbor?

a) Up milling

b) Conventional milling

c) Down milling

d) None of the mentioned

Answer: c

Explanation: Down milling generates less radial pressure. In down milling, chip thickness decrease gradually from maximum at the start of cut to the zero at the end.

10. Which of the following milling operation will require lower force of cut?

a) Up milling

b) Climb milling

c) Down milling

d) None of the mentioned

Answer: c

Explanation: In up milling large force is generated due to the opposite motion of tool and work piece. In up milling chip thickness increase gradually whereas in down milling chip thickness decreases gradually.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Indexing by Milling”.

1. Dividing head is generally used for changing the angular position of work piece relative to milling cutter.

a) True

b) False

Answer: a

Explanation: Indexing head are also known as dividing head and are used for changing angular position of work piece relative to milling cutter.

2. Which of the following is precision dividing head used in milling?

a) Plain dividing head

b) Universal dividing head

c) Optical dividing head

d) None of the mentioned

Answer: c

Explanation: Optical dividing heads are precision heads and are used in precision indexing work. Indexing head are also known as dividing head and are used for changing angular position of work piece relative to milling cutter.

3. Circumference of a work piece is to be divided in 8 equal division using index plate of 24 slots. Indexing ratio is equal to

a) 2

b) 3

c) 4

d) 6

Answer: b

Explanation: Indexing ratio = / . Hence indexing ratio is equal to 3.

4. Circumference of a work piece is to be divided in 10 equal division using an index plate of 550 slots. Indexing ratio is equal to

a) 2

b) 3

c) 5

d) 6

Answer: b

Explanation: Indexing ratio = / . Hence indexing ratio is equal to 3.

5. Circumference of a work piece is to be divided into 60 equal divisions using simple indexing method having 40 worm wheel teeth. Indexing movement will be

a) 12 holes on 18 hole circle

b) 16 holes on 18 hole circle

c) 12 holes on 21 hole circle

d) 16 holes on 21 hole circle

Answer: a

Explanation: Indexing movement = / .Hence indexing movement is equal to 12 holes on 18 hole circle.

6. Circumference of a work piece is to be divided into 35 equal divisions using simple indexing method having 40 worm wheel teeth. Indexing movement will be

a) 3 holes on 18 hole circle

b) 16 holes on 18 hole circle

c) 3 holes on 21 hole circle

d) 16 holes on 21 hole circle

Answer: c

Explanation: Indexing movement = / . Hence indexing movement is equal to 3 holes on 21 hole circle.

7. Circumference of a work piece is to be divided into 6 equal divisions using direct indexing method. Indexing movement will be

a) 5

b) 2

c) 3

d) 4

Answer: d

Explanation: Indexing movement = / . Hence indexing movement is equal to 4.

8. Circumference of a work piece is to be divided into 12 equal divisions using direct indexing method. Indexing movement will be

a) 5

b) 2

c) 3

d) 4

Answer: b

Explanation: Indexing movement = / . Hence indexing movement is equal to 2.

9. What will be the index movement to mill a hexagon head screw by using direct indexing?

a) 2

b) 3

c) 4

d) 6

Answer: c

Explanation: For direct indexing, indexing movement = / . Hence indexing movement is equal to 4.

10. Which one of the following is correct about compound indexing of 93 divisions?

a) 28 holes in 21 circle forward and 28 holes in 31 circle backwards

b) 26 holes in 21 circle forward and 28 holes in 30 circle backwards

c) 28 holes in 21 circle forward and 28 holes in 30 circle backwards

d) None of the mentioned

Answer: a

Explanation: For compound Indexing use  =  + – ), where N denotes the number of division.Hence indexing movement is equal to 28 holes in 21 circle forward and 28 holes in 31 circle backwards.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Geometry of Twist Drills-1”.

1. Part of twist drill which carries flutes and extends from dead centre up to the start of the neck is known as

a) Body

b) Point

c) Lip

d) Chisel edge

Answer: a

Explanation: Body of twist drill carries flutes and extends from dead centre up to the start of a neck. This is the longest part of a twist drill.

2. Part of drill between neck and tang is known as

a) Body

b) Point

c) Shank

d) Chisel edge

Answer: c

Explanation: Shank of twist drill is between neck and tang.

3. Edge formed at extreme tip due to the intersection of flanks, is known as

a) Body

b) Point

c) Lip

d) Chisel edge

Answer: d

Explanation: Chisel edge is formed at extreme tip due to the intersection of flanks. It is at the extreme edge of chisel edge.

4. Cone shaped surface formed at the end of the flutes which contains dead centre, lips and flanks etc. is known as

a) Body

b) Point

c) Lip

d) Chisel edge

Answer: b

Explanation: Point is a Cone shaped surface formed at the end of the flutes which contains dead centre, lips and flanks etc. It is at the end part of the twist drill.

5. Main cutting part of drill is

a) Body

b) Point

c) Lip

d) Chisel edge

Answer: c

Explanation: Lip is the main cutting part of the drill and is also called cutting edge. Material removed first at chisel edge.

6. Intersection of each faces and flank form

a) Body

b) Point

c) Lip

d) Chisel edge

Answer: a

Explanation: Lip is the main cutting part of the drill and is also called cutting edge. It is formed at Intersection of each faces and flank.

7. Small clearance provided in diameter of twist drills adjacent to land is known as

a) Body clearance

b) Point clearance

c) Lip clearance

d) Chisel edge clearance

Answer: a

Explanation: Body clearance is provided in diameter of twist drills adjacent to land. This clearance help in the removal of material during cutting.

8. Which of the following help in reducing friction between drill and the walls of the hole in twist drills?

a) Body clearance

b) Point clearance

c) Lip clearance

d) Chisel edge clearance

Answer: a

Explanation: Body clearance reduces friction between drill and the walls. It helps in smooth drilling of holes during the operation.

9. Narrow flat surface running along flutes of twist drill on its leading edge is known as

a) Body

b) Point

c) Lip

d) Land

Answer: d

Explanation: Land is the narrow flat surface running along flutes of twist drill on its leading. It is the flat part of a twist drill.

10. Narrow flat surface running along flutes of twist drill on its leading edge is known as

a) Body

b) Point

c) Lip

d) Margin

Answer: d

Explanation: Margin is the narrow flat surface running along flutes of twist drill on its leading. It is also known as land.

This set of Manufacturing Engineering Questions for entrance exams focuses on “Geometry of Twist Drills”.

1. Small part of conical surface of a point which is grounded to provide relief near the cutting edge in twist drills is known as

a) Lip clearance

b) Face

c) Flute

d) Flank

Answer: a

Explanation: Lip clearance is a Small part of conical surface of a point which is grounded to provide relief near the cutting edge.

2. In twist drills, curved surface of flute near the lip is known as

a) Lip clearance

b) Face

c) Flute

d) Flank

Answer: b

Explanation: Face is the curved surface of flute near the lip. Lip clearance is a Small part of conical surface of a point which is grounded to provide relief near the cutting edge.

3. In twist drills helical grooves in the body of drill are called

a) Lip clearance

b) Face

c) Flute

d) Flank

Answer: c

Explanation: Flutes are grooves in the body of a drill. These grooves are helical in shape. They provide passage for chip flow.

4. Which of the following part of twist drill is responsible for making chips curl and provide passage for chip flow?

a) Lip clearance

b) Face

c) Flute

d) Flank

Answer: c

Explanation: Flutes are grooves in the body of a drill. These grooves are helical in shape. They provide passage for chip flow.

5. In twist drills, curved surface on either side of dead centre, confined between lip on its on its one side and face of the flute on its other side is called

a) Lip clearance

b) Face

c) Flute

d) Flank

Answer: d

Explanation: Flank is on either side of dead centre. Curved surface on either side of dead centre, confined between lip on its on its one side and face of the flute on its other side is called flank.

6. Which of the following separate flute from each other in twist drills?

a) Web

b) Chisel edge corner

c) Outer corner

d) Neck

Answer: a

Explanation: Web is a central metal column and separates flutes.

7. In twist drills, chisel edge and lip intersect at

a) Web

b) Chisel edge corner

c) Outer corner

d) Neck

Answer: b

Explanation: Chisel edge corner is the point where chisel edge and lip intersects.

8. In twist drills, face and flank intersect at a corner at the extreme of dead centre, that corner is known as

a) Web

b) Chisel edge corner

c) Outer corner

d) Neck

Answer: c

Explanation: At outer corner face and flak intersects. Face and flank intersect at corner at the extreme of dead centre, that corner is known as outer corner.

9. Which of the following part of twist drill separates body from shank?

a) Web

b) Chisel edge corner

c) Outer corner

d) Neck

Answer: d

Explanation: Neck separates body and shank.

10. In twist drills, end of tapered shank is attached to

a) Web

b) Chisel edge corner

c) Outer corner

d) Tang

Answer: d

Explanation: Tang is a flat portion with rectangular cross section provided at the end of shank.

11. In twist drills, Edge formed by an intersection of body clearance and flute is known as

a) Web

b) Chisel edge corner

c) Heel

d) Neck

Answer: c

Explanation: Heel is an edge formed by an intersection of body clearance and flute.

This set of Manufacturing Engineering Questions for campus interviews focuses on “Geometry of Twist Drills”.

1. Length measured along the axis between the dead centre and start of neck of a twist drill is known as

a) Body length

b) Flute length

c) Lip length

d) Overall length

Answer: a

Explanation: Body length is the length measured along the axis between the dead centre and start of neck. Flute length is the length measured parallel to the axis between the dead centre and the point of termination of flute near the neck.

2. Length measured parallel to the axis between the dead centre and the point of termination of flute near the neck is known as

a) Body length

b) Flute length

c) Lip length

d) Overall length

Answer: b

Explanation: Flute length is the length measured parallel to the axis between the dead centre and the point of termination of flute near the neck. Body length is the length measured along the axis between the dead centre and start of neck.

3. In twist drill, distance measured between the chisel edge corner and the outer corner is known as

a) Body length

b) Flute length

c) Lip length

d) Overall length

Answer: c

Explanation: Lip length is the length measured between the chisel edge corner and the outer corner. Body length is the length measured along the axis between the dead centre and start of a neck.

4. In twist drills, length measured along the axis between the dead centre and the extreme end of the tang is known as

a) Body length

b) Flute length

c) Lip length

d) Overall length

Answer: d

Explanation: Overall length is the length measured along the axis between the dead centre and the extreme end of the tang. Body length is the length measured along the axis between the dead centre and start of neck.

5. Reduction in body diameter measured along the radius of twist drill is known as

a) Body length

b) Lead of helix

c) Depth of body clearance

d) Core taper

Answer: c

Explanation: Depth of body clearance is a reduction in body diameter measured along radius of twist drill.

6. Web taper is also known as

a) Body length

b) Lead of helix

c) Depth of body clearance

d) Core taper

Answer: d

Explanation: Core taper is the increase in core thickness. Web taper is also known as core taper.

7. Measure of increase in web thickness or core thickness, starting from the minimum at the point end to the maximum at the shank end of twist drill

a) Body length

b) Lead of helix

c) Depth of body clearance

d) Core taper

Answer: d

Explanation: Core taper or web taper is the measure of the increase in web thickness or core thickness, starting from the minimum at the point end to the maximum at the shank end of twist drill.

8. Axial distance measured between two corresponding points on a flute in its one complete turn in twist drill is known as

a) Body length

b) Lead of helix

c) Depth of body clearance

d) Core taper

Answer: b

Explanation: Lead helix is the axial distance measured between two corresponding points on a flute in its one complete turn in twist drill.

9. Rake angle of drill is also as

a) Taper angle

b) Friction angle

c) Helix angle

d) None of the mentioned

Answer: c

Explanation: Helix angle of drill is also known as rake angle. Lead helix is the axial distance measured between two corresponding points on a flute in its one complete turn in twist drill.

10. Which of the following is correct about helix angle for right hand flute drill?

a) Positive

b) Negative

c) Zero

d) None of the mentioned

Answer: a

Explanation: Helix angle have positive value for right handed flute. Helix angle of drill is also known as rake angle.

This set of Manufacturing Engineering aptitude tests focuses on “Geometry of Twist Drills”.

1. Which of the following is correct about helix angle for left hand flute drill?

a) Positive

b) Negative

c) Zero

d) None of the mentioned

Answer: b

Explanation: Helix angle have negative value for right handed flute.

2. Which of the following is correct about helix angle for parallel flute drill?

a) Positive

b) Negative

c) Zero

d) None of the mentioned

Answer: c

Explanation: Helix angle have zero value for right handed flute.

3. Which of the following drill is most suitable for softer material?

a) 48 degree helix angle drill

b) 68 degree helix angle drill

c) 58 degree helix angle drill

d) 18 degree helix angle drill

Answer: d

Explanation: Helix angle with lower value is more suitable for soft material. Helix angle have negative value for right handed flute.

4. When the value of helix angle increases in drills, the value of required torque for rotation of drill will

a) Increase

b) Decrease

c) First increase then decrease

d) First decrease then increase

Answer: b

Explanation: Torque required is inversely proportional to helix angle of drill. When the value of helix angle increases in drills, the value of required torque for rotation of drill will increase.

5. Point angle of drill is also known as

a) Taper angle

b) Friction angle

c) Helix angle

d) Cutting angle

Answer: c

Explanation: Point angle of drill is also known as cutting angle. Small point angle drills are favored for brittle material because brittle material has low chip flow. Small point angle makes drill strong. But it reduces the passage area for chip flow.

6. Which of the following drill will be most suitable for drilling of brittle material?

a) Small point angle drill

b) Large point angle drill

c) Zero point angles drill

d) None of the mentioned

Answer: a

Explanation: Small point angle drills are favored for brittle material because brittle material has low chip flow. Small point angle makes drill strong. But it reduces the passage area for chip flow. Point angle of drill is also known as cutting angle.

7. Which of the following drill will be most suitable for drilling of ductile and soft material?

a) Small point angle drill

b) Large point angle drill

c) Zero point angles drill

d) None of the mentioned

Answer: b

Explanation: Large point angle drills are favored for ductile material because ductile material has high chip flow. Large point angle makes drill weak but increases chip flow passage area. Point angle of drill is also known as cutting angle.

8. Clearance in drill is

a) Directly proportional to chisel edge angle

b) Inversely proportional to chisel edge angle

c) Does not depend on chisel edge angle

d) None of the mentioned

Answer: a

Explanation: Greater the chisel edge angle larger will be the clearance.

9. For drilling of brass work piece, most suitable rake angle in degrees for drill will be

a) 12

b) 15

c) 0

d) -9

Answer: c

Explanation: Brass is neither brittle nor ductile and hence zero rake angle is preferred for drilling of brass work piece.

10. Which of the following is most suitable range of lip clearance angel in degrees for drilling of aluminum work piece?

a) 8-12

b) 3-2

c) 50-60

d) None of the mentioned

Answer: a

Explanation: 8 degree to 12 degree is the best range of lip clearance angle for most of the operations.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Drilling “.

1. Producing circular hole in a solid metal by means of revolving tool is known as

a) Drilling

b) Reaming

c) Boring

d) Counter boring

Answer: a

Explanation: Drilling is defined as production of generally circular hole by using a revolving tool.

2. Operation of finishing previously drilled hole in order to bring it to accurate size and have good surface finish is known as

a) Drilling

b) Reaming

c) Boring

d) Counter boring

Answer: b

Explanation: Reaming is a finishing operation of drilled hole. It is done to improve surface finish of drilled hole.

3. Process of enlarging the hole size and enhancing its surface finish is known as

a) Drilling

b) Reaming

c) Boring

d) Counter boring

Answer: c

Explanation: Once the hole is drilled by using drilling operation, later the diameter of hole can be increased by using boring operation.

4. Process of enlarging only a small part of hole is also known as

a) Drilling

b) Reaming

c) Boring

d) Counter boring

Answer: d

Explanation: Once the hole is drilled by using drilling operation, later the diameter of some part of hole can be increased by using counter boring operation.

5. Operation of enlarging the end of the hole to give conical shape at end is known as

a) Drilling

b) Reaming

c) Boring

d) Counter sinking

Answer: d

Explanation: Once the hole is drilled by using drilling operation, later the ends of hole can be machined into conical shape for proper adjustment of washer or other machine parts by using Counter sinking operation.

6. Operation used to form internal threads is known as

a) Drilling

b) Reaming

c) Boring

d) Tapping

Answer: d

Explanation: Tapping is the process of forming internal threads by means of tool called tap.

7. If ‘D’ is hole diameter, then general value for a compulsory approach for through hole can be taken as

a) 0.3*D

b) 0.1*D

c) 0.5*D

d) 0.8*D

Answer: c

Explanation: For through hole, X = 0.5*D.

8. If ‘D’ is hole diameter, then general value for a compulsory approach for blind hole can be taken as

a) 0.3*D

b) 0.1*D

c) 0.5*D

d) 0.8*D

Answer: a

Explanation: For through hole, X = 0.3*D.

9. If 20mm hole is needed to be drilled using a drill having semi point angle of 15 degrees. Value of compulsory approach in mm is

a) 37.2

b) 45.3

c) 87.1

d) 13.3

Answer: a

Explanation: X = / ).

10. If 20mm hole is needed to be drilled using a drill having point angle of 15 degrees. Value of compulsory approach in mm is

a) 37.2

b) 45.3

c) 75.95

d) 13.3

Answer: c

Explanation: X = / ). Semi point angle = point angle/2.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Reaming”.

1. Helical groves on a body of reamers are known as

a) Flutes

b) Face

c) Heel

d) Recess

Answer: a

Explanation: Flutes are helical grooves present on the body of reamers. They help in better machining process using reamers.

2. In reamers, flute surface adjacent to cutting is known as

a) Flutes

b) Face

c) Heel

d) Recess

Answer: b

Explanation: Face of reamers is adjacent to cutting edge. They help in cutting during machining process using reamers.

3. Small flat surface in between cutting edge and the heel of a reamer is known as

a) Flutes

b) Face

c) Heel

d) Land

Answer: d

Explanation: Land is the small narrow surface between cutting edge and heel. They help in better machining process using reamers.

4. In reamers, edge formed by an intersection of secondary clearance and flute is known as

a) Flutes

b) Face

c) Heel

d) Recess

Answer: c

Explanation: Heel is the edge formed by an intersection of secondary clearance and flute. They help in better machining process using reamers.

5. Reduction in body diameter toward shank of reamer is known as

a) Flutes

b) Face

c) Heel

d) Recess

Answer: d

Explanation: Recess is the reduction in body diameter toward shank. They help in better machining process using reamers.

6. Maximum diameter of reamer at entering is also known as

a) Flutes

b) Face

c) Actual size

d) Recess

Answer: c

Explanation: Actual size of reamer is the maximum diameter of the reamer.

7. Portion of reamer which carries flute is known as

a) Flutes

b) Face

c) Body

d) Recess

Answer: c

Explanation: Body carries flute on it. Face of reamers is adjacent to cutting edge.

8. Tapered of reamer by which it can be gripped is known as

a) Flutes

b) Face

c) Heel

d) Shank

Answer: d

Explanation: Shank is used for gripping reamers and rotating. Face of reamers is adjacent to cutting edge.

9. Longitudinal center line which is concentric with diameter of reamer is known as

a) Flutes

b) Axis

c) Heel

d) Recess

Answer: b

Explanation: Axis divides reamers in two symmetric part.

10. If reamer is found to be cutting while rotating in clockwise direction when viewed against the entering end at a right angle to it is known as

a) Left handed reamer

b) Central reamer

c) Right handed reamer

d) None of the mentioned

Answer: a

Explanation: Left handed reamer rotate in clockwise during cutting when viewed against the entering end at right angle.

11. If reamer is found to be cutting while rotating in anti-clockwise direction when viewed against the entering end at a right angle to it is known as

a) Left handed reamer

b) Central reamer

c) Right handed reamer

d) None of the mentioned

Answer: c

Explanation: Right handed reamer rotate in anti-clockwise during cutting when viewed against the entering end at right angle.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Grinding Wheel-1”.

1. Grain number of grinding wheel is ___ to grain size.

a) Directly proportional

b) Inversely proportional

c) Does not depend

d) None of the mentioned

Answer: b

Explanation: Grain number = 1/. Grain number is similar to density of grains on grinding wheels.

2. Which of the following is a correct range for grain number of the grinding wheel for coarse grains?

a) 220-600

b) 80-180

c) 30-60

d) 10-24

Answer: d

Explanation: For coarse grain, grain number ranges from 10 to 24.

3. Which of the following is the correct range for grain number of the grinding wheel for medium grains?

a) 220-600

b) 80-180

c) 30-60

d) 10-24

Answer: c

Explanation: For medium grain, grain number ranges from 30 to 60.

4. Which of the following is a correct range for grain number of the grinding wheel for fine grains?

a) 220-600

b) 80-180

c) 30-60

d) 10-24

Answer: b

Explanation: For fine grains, grain number ranges from 80 to 180.

5. Which of the following is the correct range for grain number of the grinding wheel for very fine grains?

a) 220-600

b) 80-180

c) 30-60

d) 10-24

Answer: a

Explanation: For very fine grains, grain number ranges from 220 to 600.

6. Which of the following grinding machine will give a better result for rough machining?

a) Fine grain

b) Very fine grain

c) Coarse grain

d) None of the mentioned

Answer: c

Explanation: Coarse grain wheel will give better metal removal rate and space for chip removal as rate of chip flow in rough machining is high.

7. Which of the following grinding machine will give a better result for finish machining operation?

a) Fine grain

b) Medium grain

c) Coarse grain

d) None of the mentioned

Answer: c

Explanation: Fine grain wheel will give smaller metal removal rate and hence better for finishing operations.

8. Which of the following symbol’s range of alphabet represent soft grain in grinding wheel?

a) A – H

b) I – P

c) Q – T

d) T – Z

Answer: a

Explanation: A-H represents soft grains in grinding wheel.

9. Which of the following symbol’s range of alphabet represent medium hardness grain in grinding wheel?

a) A – H

b) I – P

c) Q – T

d) T – Z

Answer: b

Explanation: I-P represents medium hard grains in grinding wheel.

10. Which of the following symbol’s range of alphabet represent hard grain in grinding wheel?

a) D – H

b) I – P

c) A – D

d) Q – Z

Answer: a

Explanation: A-H represents soft grains in grinding wheel.

This set of Manufacturing Engineering Problems focuses on “Grinding Wheel-2”.

1. Which of the following range of numbers represents dense structure of abrasives?

a) 0-7

b) 8-10

c) 10-12

d) 12-16

Answer: a

Explanation: 0 – 7 represents dense structures. It represents distance between the grain in grinding wheel.

2. Which of the following range of numbers represents open structure of abrasives?

a) 0-3

b) 4-6

c) 8-16

d) None of the mentioned

Answer: c

Explanation: 8 – 16 represents open structure. It represents distance between the grain in grinding wheel.

3. Which of the following represents the correct symbol of vertified bond in a specification of grinding wheel?

a) V

b) R

c) B

d) S

Answer: a

Explanation: ‘V’ represents for vertified bond. Fifth place of ISO designation of grinding wheel represents type of bond.

4. Which of the following represents the correct symbol of rubber bond in a specification of grinding wheel?

a) V

b) R

c) B

d) S

Answer: b

Explanation: ‘R’ represents for rubber bond. Fifth place of ISO designation of grinding wheel represents type of bond.

5. Which of the following represents the correct symbol of Resin bond in a specification of grinding wheel?

a) V

b) R

c) B

d) S

Answer: b

Explanation: ‘B’ represents for resin bond. Fifth place of ISO designation of grinding wheel represents type of bond.

6. Resin bond is also known

a) Vertified bond

b) Rubber bond

c) Silicate bond

d) Bakelite bond

Answer: d

Explanation: Resin bond is also known as Bakelite bond and is represented by symbol ‘B’. Fifth place of ISO designation of grinding wheel represents type of bond.

7. Which of the following represents the correct symbol of Silicate bond in a specification of grinding wheel?

a) V

b) R

c) B

d) S

Answer: d

Explanation: ‘S’ represents for Silicate bond. Fifth place of ISO designation of grinding wheel represents type of bond.

8. Which of the following represents the correct symbol of Shellac bond in a specification of grinding wheel?

a) V

b) P

c) B

d) S

Answer: b

Explanation: ‘P’ represents for shellac bond. Fifth place of ISO designation of grinding wheel represents type of bond.

9. Which of the following represents the correct symbol of epoxy bond in a specification of grinding wheel?

a) V

b) R

c) P

d) S

Answer: b

Explanation: ‘P’ represents for epoxy bond. Fifth place of ISO designation of grinding wheel represents type of bond.

10. Which of the following will be better to use for machining of hard work piece?

a) V-bond

b) R-bond

c) Both V and R bond

d) None of the mentioned

Answer: a

Explanation: Vertified bond grinding wheel is generally used for machining of hard work piece. Fifth place of ISO designation of grinding wheel represents type of bond.

This set of Basic Manufacturing Engineering Questions & Answers focuses on “Grinding Wheel-3”.

1. Which of the following will be better to use for machining of soft work piece?

a) V-bond

b) R-bond

c) Both V and R bond

d) None of the mentioned

Answer: b

Explanation: Rubber bond grinding wheel is generally used for machining of soft work piece. Fifth place of ISO designation of grinding wheel represents type of bond.

2. Which of the following grinding wheel would be more economical for grinding of hard work piece?

a) Soft grinding wheel

b) Hard grinding wheel

c) Both hard and soft grinding wheel

d) None of the mentioned

Answer: a

Explanation: In soft grinding wheels, during machining of hard work piece glazing will occur after long time.

3. Which of the following grinding wheel would be more economical for grinding of soft work piece?

a) Soft grinding wheel

b) Hard grinding wheel

c) Both hard and soft grinding wheel

d) None of the mentioned

Answer: b

Explanation: In hard grinding wheels, during machining of soft work piece glazing will occur after long time and grains of grinding wheel will be effectively utilized before coming out from the wheel.

4. Which of the following grinding wheel would be more economical for grinding of hard work piece?

a) Open structure grinding wheel

b) Dense structure wheel

c) Both dense and open structure grinding wheel

d) None of the mentioned

Answer: b

Explanation: In dense structure grinding wheels, during machining of hard work piece material removal rate is small and also wheel has good strength.

5. Which of the following grinding wheel would be more economical for grinding of soft work piece?

a) Open structure grinding wheel

b) Dense structure wheel

c) Both dense and open structure grinding wheel

d) None of the mentioned

Answer: a

Explanation: In open structure grinding wheels, during machining of soft work piece material removal rate is large and space for chip flow is also large due to more space between grains of wheel.

6. Material removal rate of grinding process in comparison to material removal rate in facing on a lathe is

a) Small

b) Large

c) Same

d) Can’t say about material removal rate

Answer: a

Explanation: Material removal rate in grinding process is very small. Hence grinding is mostly use as a finishing process. Only small portion of abrasives are involved in grinding process and hence has less material removal rate.

7. Material removal rate in grinding operation is small due to

a) Negative rake angle

b) Positive rake angle

c) Zero rake angle

d) Material removal rate does not depend on the rake angle

Answer: a

Explanation: Grinding wheel have negative rake angle and hence have very small material removal rate. Hence grinding is mostly use as a finishing process.

8. Material removal rate in grinding operation is small due to

a) Only small portion of abrasives are involved in cutting

b) Positive rake angle

c) Zero rake angle

d) Material removal rate does not depend on the rake angle

Answer: a

Explanation: Only small portion of abrasives are involved in grinding process and hence has less material removal rate. Hence grinding is mostly use as a finishing process.

9. Material removal rate in grinding operation is small due to

a) Large portion of abrasives are involved in cutting

b) Positive rake angle

c) Due to temperature rise during grinding

d) Material removal rate does not depend on the rake angle

Answer: c

Explanation: Due to the increase in temperature during grinding operation some material get welded again with the chip.

10. Grinding ratio generally lies between

a) 0.5-10

b) 100-200

c) 1000-200

d) 30-40

Answer: a

Explanation: Grinding ratio = . G.R is generally between 0.5-10.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Grinding-1”.

1. Grinding wheel is specified as “A 46 K 5 B 17”. Grain size of a wheel will be

a) Coarse

b) Medium

c) Fine

d) Very Fine

Answer: b

Explanation: ’46’ represents grain size, which is medium grain size. Second value in the specification represents grain size.

2. Grinding wheel is specified as “C 8 K 5 B 17”. Grain size of a wheel will be

a) Coarse

b) Medium

c) Fine

d) Very Fine

Answer: a

Explanation: ‘8’ represents grain size, which is coarse. Second value in the specification represents grain size.

3. Grinding wheel is specified as “A 600 K 5 B 17”. Grain size of a wheel will be

a) Coarse

b) Medium

c) Fine

d) Very Fine

Answer: d

Explanation: ‘600’ represents grain size, which comes under very fine grain size. Second value in the specification represents grain size.

4. Which of the following grinding wheel will have fine grain size?

a) A 46 K 5 B 17

b) C 600 K 5 B 17

c) C 8 K 5 B 17

d) A 80 K 5 B 17

Answer: d

Explanation: Second place of ISO designation of the grinding wheel represents grain size and “80” comes under fine rain size.

5. Which of the following grinding wheel will have fine grain size?

a) A 46 K 5 B 17

b) C 600 K 5 B 17

c) C 8 K 5 B 17

d) A 80 K 5 B 17

Answer: c

Explanation: Second place of ISO designation of the grinding wheel represents grain size and “600” comes under very fine rain size.

6. Which of the following specified grinding wheel will have Aluminum oxide abrasive?

a) Z 46 K 5 B 17

b) C 600 K 5 B 17

c) C 8 K 5 B 17

d) A 80 K 5 B 17

Answer: d

Explanation: First place of ISO designation of the grinding wheel represents grain type and “A” represents aluminum oxide.

7. Which of the following specified grinding wheel will have Zirconia abrasive?

a) Z 46 K 5 B 17

b) C 600 K 5 B 17

c) C 8 K 5 B 17

d) A 80 K 5 B 17

Answer: a

Explanation: First place of ISO designation of the grinding wheel represents grain type and “Z” represents Zirconia.

8. Which of the following specified grinding wheel will have Silicon carbide abrasive?

a) Z 46 K 5 B 17

b) C 600 K 5 B 17

c) A 8 K 5 B 17

d) A 80 K 5 B 17

Answer: b

Explanation: First place of ISO designation of the grinding wheel represents grain type and “C” represents silicon carbide.

9. Operation done to make periphery of grinding wheel concentric with its axis to recover its lost shape is known as

a) Loading

b) Glazing

c) Dressing

d) Trueing

Answer: d

Explanation: Trueing is done to make periphery of grinding wheel concentric with its axis and to recover its lost shape.

10. Removing dull grains in order to make grinding wheel sharp is known as

a) Loading

b) Glazing

c) Dressing

d) Trueing

Answer: c

Explanation: Dressing is done to make grinding wheel shaft by removing dull grains at the top.

This set of Advanced Manufacturing Engineering Questions & Answers focuses on “Grinding-2”.

1. Which of the following grinding wheel specified in ISO designation will represent Vitrified bond?

a) Z 46 K 5 E 17

b) C 600 K 5 B 17

c) C 8 K 5 R 17

d) A 80 K 5 V 17

Answer: d

Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “V” represents Vitrified bond type.

2. Grinding wheel specified as “C 8 K 5 R 17” in ISO designation. What is the type of bond present in grinding wheel?

a) Vitrified

b) Rubber

c) Shellac

d) Epoxy

Answer: b

Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “R” represents rubber.

3. Which of the following grinding wheel specified in ISO designation will represent Resin bond?

a) Z 46 K 5 E 17

b) C 600 K 5 B 17

c) C 8 K 5 R 17

d) A 80 K 5 V 17

Answer: b

Explanation: Fifth place of ISO designation of the grinding wheel represents the type of bond and “B” represents resin bond.

4. Which of the following grinding wheel specified in ISO designation will represent Shellac bond?

a) Z 46 K 5 E 17

b) C 600 K 5 B 17

c) C 8 K 5 R 17

d) A 80 K 5 V 17

Answer: a

Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “E” represents shellac.

5. Grinding wheel specified as “A 8 K 5 P 17” in ISO designation. What is the type of bond present in grinding wheel?

a) Vitrified

b) Rubber

c) Shellac

d) Epoxy

Answer: d

Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “P” represents rubber.

6. Which of the following will not have open structure?

a) A 46 K 5 B 17

b) C 600 K 8 B 17

c) C 8 K 5 9 17

d) A 80 K 10 B 17

Answer: a

Explanation: Fourth place of ISO designation of the grinding wheel represents Structure and “5” comes under dense structure.

7. Which of the following has open structure?

a) A 46 K 5 B 17

b) C 600 K 8 B 17

c) C 8 K 5 3 17

d) A 80 K 4 B 17

Answer: b

Explanation: Fourth place of ISO designation of the grinding wheel represents Structure and “8” comes under open structure.

8. A grinding wheel is specified as “C 10 K 8 R 17”. Which of the following is correct about this grinding wheel?

a) Very fine grains

b) Open structure

c) Aluminum oxide abrasive

d) Coarse grain

Answer: b

Explanation: Fourth place of ISO designation of the grinding wheel represents Structure and “8” comes under open structure.

9. A grinding wheel is specified as “A 5 K 5 R 17”. Which of the following is correct about this grinding wheel?

a) Very fine grains

b) Open structure

c) Aluminum oxide abrasive

d) Coarse grain

Answer: c

Explanation: First place of ISO designation of the grinding wheel represents grain type and “A” represents aluminum oxide.

10. A grinding wheel is specified as “C 5 K 5 R 17”. Which of the following is correct about this grinding wheel?

a) Very fine grains

b) Open structure

c) Rubber bond

d) Coarse grain

Answer: c

Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “R” represents rubber.

11. A grinding wheel is specified as “A 8 K 5 P 17”. Which of the following is correct about this grinding wheel?

a) Very fine grains

b) Open structure

c) Rubber bond

d) Coarse grain

Answer: d

Explanation: ‘8’ represents grain size, which is coarse.

12. Friability of grinding wheel is associated to

a) Hardness

b) Fracture

c) Size

d) None of the mentioned

Answer: b

Explanation: Friability is the ability to fracture under pressure so that when cutting edge become dull, the grain breaks off and exposes new grains which are sharp.

13. With time, grinding wheel starts rubbing work piece instead of cutting, due to a decrease in sharpness. This phenomenon is known as

a) Loading

b) Glazing

c) Dressing

d) Trueing

Answer: b

Explanation: Glazing occurs when grinding wheel starts rubbing work piece instead of cutting.

14. Loss in the sharpness of grinding wheel due to the presence of chips in gaps of grains is termed as

a) Loading

b) Glazing

c) Dressing

d) Trueing

Answer: a

Explanation: Loading decrease sharpness of grinding wheel, when foreign material comes in between free space of wheel.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Surface Finishing Operations”.

1. Which of the following is a surface finishing operation?

a) Drilling

b) Honing

c) Milling

d) Turning

Answer: b

Explanation: Honing is a surface finishing operation used to give better surface finish and have very small material removal rate.

2. Which of the following is a surface finishing operation?

a) Drilling

b) Lapping

c) Milling

d) Turning

Answer: b

Explanation: Lapping is a surface finishing operation used to give better surface finish and have very small material removal rate.

3. Which of the following process has the lowest cutting speed?

a) Drilling

b) Honing

c) Milling

d) Turning

Answer: b

Explanation: Honing is a surface finishing operation and hence it is generally performed at low speed.

4. Which of the following process has the lowest cutting speed?

a) Slotting

b) Lapping

c) Milling

d) Reaming

Answer: b

Explanation: Lapping is a surface finishing operation and hence it is generally performed at low speed.

5. Which of the following process have the lowest metal removal rate?

a) Drilling

b) Reaming

c) Milling

d) Lapping

Answer: b

Explanation: Lapping is a surface finishing operation and hence have low metal removal rate.

6. Which of the following process have the lowest metal removal rate?

a) Drilling

b) Reaming

c) Milling

d) Honing

Answer: d

Explanation: Honing is a surface finishing operation and hence have low metal removal rate.

7. Which of the following is the correct grain size range of abrasive grains for honing stones?

a) 800 grit to 1000 grit

b) 5 grit to 10 grit

c) 50 grit to 60 grit

d) 80 grit to 600 grit

Answer: d

Explanation: 80 grit to 600 grit is the correct grain size range of abrasive grains for honing stones.

8. For practical honing conditions, cross hatch angle in degrees is generally taken in the range of

a) 20 to 40

b) 40 to 50

c) 50 to 60

d) 10 to 15

Answer: a

Explanation: Cross hatch angle is generally taken from 20 degrees to 40 degrees.

9. During a honing process, reciprocating speed of honing tool was 9m/min with a rotary speed of 25m/min. Cross hatch angle in degrees is equal to

a) 40

b) 35

c) 30

d) 25

Answer: a

Explanation: tan = / . Cross hatch angle = 2*X, where ‘X’ is the cross hatch angle.

10. During a honing process, reciprocating speed of honing tool was 9m/min with a cross hatch angle of 30 degree. Rotary speed in m/min is equal to

a) 33.58

b) 35

c) 30

d) 25.23

Answer: a

Explanation: tan = / . Cross hatch angle = 2*X, where ‘X is the cross hatch angle.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Electric Discharge Machining”.

1. Which of the following machine uses non conventional machining technique for metal removal?

a) Grinding machine

b) Milling machine

c) Electric discharge machine

d) None of the mentioned

Answer: c

Explanation: Electronic discharge machine is a non conventional machining technique for metal removal.

2. Which of the following material cannot be machined using electronic discharge machine?

a) Iron

b) Aluminum

c) Copper

d) Wood

Answer: d

Explanation: Wood is a bad conductor of electricity and hence cannot be machined using electronic discharge machine.

3. Which of the following material can be machined using electronic discharge machine?

a) Iron

b) Rubber

c) Plastic

d) Wood

Answer: a

Explanation: Iron is a good conductor of electricity and hence can be machined using electronic discharge machine.

4. Which of the following EDM machine is used for cutting shapes cut out of a flat sheet or plate of metal?

a) Wire EDM

b) Sinker EDM

c) Wire and Sinker EDM both

d) None of the mentioned

Answer: a

Explanation: Wire EDM used for cutting shapes cut out of flat sheet or plate of metal. It is an unconventional process of machining.

5. Which of the following EDM machine is used for die cast tooling?

a) Wire EDM

b) Sinker EDM

c) Wire and Sinker EDM both

d) None of the mentioned

Answer: b

Explanation: Sinker EDM is used for die cast tooling. It is an unconventional process of machining.

6. Dielectric medium in EDM is used for

a) Flushing away the debris

b) To make the medium conducting

c) To decrease the material removal rate

d) None of the mentioned

Answer: a

Explanation: Dielectric in EDM is used for flushing away the debris generated during the process of machining, which may slow down the material removal rate if not removed instantly.

7. Material removal rate in EDM increases with

a) Increase in melting point of work piece

b) Increase in Current

c) Decrease in current

d) None of the mentioned

Answer: b

Explanation: MRR is directly proportional to the current.

8. Material removal rate in EDM increases with

a) Increase in melting point of work piece

b) Decrease in Current

c) Decrease in melting point of work piece

d) None of the mentioned

Answer: c

Explanation: MRR is inversely proportional to a melting point of work piece.

9. For maximum power delivery using resistance capacitance relaxation circuit in EDM, discharge voltage should ___ % of the supply voltage?

a) 80

b) 23

c) 65

d) 72

Answer: d

Explanation: Find optimum value using L-C circuits.

10. In an EDM machine, metal removal rate is 1.937 cubic mm / min. If total amount of material to removed is 600 cubic mm. Time required in min will be

a) 100

b) 200

c) 309

d) 402

Answer: c

Explanation: Time required= .

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Electrochemical Machining”.

1. Which of the following is un-conventional machining process?

a) Grinding

b) Milling

c) Turning

d) Electro chemical machining

Answer: d

Explanation: Electro chemical machining is an un-conventional machining process used for large material removal from the surface using electricity generated due to chemical reactions.

2. Which of the following is conventional machining process?

a) Electro chemical machining

b) Milling

c) Electron discharge machining

d) None of the mentioned

Answer: b

Explanation: Milling is a conventional machining process used for material removal from the surface.

3. In ECM, heavy electrical sparks are created.

a) True

b) False

Answer: b

Explanation: Sparks are generated in EDM, by using high voltage current, for proper erosion of material.

4. In ECM, tool does not touch the work piece.

a) True

b) False

Answer: a

Explanation: Tool is very near to work piece but does not touch it in ECM.

5. Which of the following is correct about ECM?

a) Erosion of metal takes place as a reverse process of electroplating

b) Thermal stresses are induced

c) Mechanical stresses are induced

d) None of the mentioned

Answer: a

Explanation: In ECM, erosion of metal takes place as reverse process of electroplating.

6. Which of the following material cannot be machined using electro chemical machining?

a) Iron

b) Aluminum

c) Copper

d) Wood

Answer: d

Explanation: Wood is a bad conductor of electricity and hence cannot be machined using electro chemical machining.

7. Which of the following material can be machined using electro chemical machining?

a) Iron

b) Rubber

c) Plastic

d) Wood

Answer: a

Explanation: Iron is a good conductor of electricity and hence can be machined using electro chemical machining.

8. Electrode gap in electro chemical machining is generally ranged from

a) 0.5 mm to 0.9 mm

b) 1.1 mm to 1.2 mm

c) 0.1 mm to 0.2 mm

d) 3.1 mm to 4.2 mm

Answer: c

Explanation: Electrode gap in electro chemical machining is generally ranged from 0.1 mm to 0.2 mm.

9. Electrolytes used in ECM must posses

a) Low electrical conductivity

b) Low chemical stability

c) High electrical conductivity

d) None of the mentioned

Answer: c

Explanation: Electrolytes used in ECM must have high electrical conductivity.

10. Which of the following is not a function of electrolyte in ECM?

a) It completes the circuit

b) It helps in electrochemical reaction

c) It carries away heat and waste product

d) It provide non reactive environment

Answer: d

Explanation: Electrolyte provides reactive environment for chemical reactions to takes place.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Laser Beam Machining”.

1. LASER stands for

a) Light amplification by stimulated emission of radiation

b) Light amplification by stimulated erosion of reaction

c) Light amplification by stimulated erosion of radiation

d) Light amplification by stimulated emission of reaction

Answer: a

Explanation: LASER stands for light amplification by stimulated emission of radiation. LASER have a high amount of energy, which can be used to generate heat.

2. Ruby laser is most efficient when

a) Kept cold

b) Kept hot

c) Kept at normal temperature

d) None of the mentioned

Answer: a

Explanation: Ruby laser is most efficient when it is kept cold. Ruby laser is used to produce a LASER. It generally uses chromium ions to produce LASER.

3. Time of machining in the laser beam machining process increases with

a) Decrease in power supply

b) Decrease in laser beam spot diameter

c) Increase in cutting speed

d) None of the mentioned

Answer: b

Explanation: Time of machining in the laser beam machining process is directly proportional to laser beam spot diameter. Larger the diameter, larger will be the HAZ.

4. Laser beam machining process can be used for

a) Conductors

b) Insulators

c) Metals

d) All of the mentioned

Answer: d

Explanation: Laser beam machining is more versatile and can be used for the metal as well as non metal. It does not require vacuum environment.

5. In laser beam machining process, as compared to other unconventional machining processes, heat affected zone is

a) Larger

b) Smaller

c) Not present

d) None of the mentioned

Answer: b

Explanation: In laser beam machining process heat affected zone have smaller area in comparison with other unconventional machining processes. It does not require vacuum environment.

6. Which of the following is an unconventional process of machining?

a) Turning

b) Milling

c) Drilling

d) Laser beam machining process

Answer: d

Explanation: Laser beam machining is an unconventional process of machining. It does not require vacuum environment.

7. Which of the following is a conventional process of machining?

a) Electro chemical machining

b) Electron beam machining

c) Drilling

d) Laser beam machining process

Answer: d

Explanation: Drilling is a conventional process of machining. Laser beam machining is an unconventional process of machining.

8. For machining of plastic material which of the unconventional process can be used effectively?

a) Electro chemical machining

b) Electron beam machining

c) Laser beam machining process

d) None of the mentioned

Answer: c

Explanation: Laser beam machining is more versatile and can be used for metal as well as non metal. In laser beam machining process heat affected zone have smaller area in comparison with other unconventional machining processes.

9. Time of cutting in laser beam machining process increases

a) With decrease in cutting speed

b) With Increase in Cutting speed

c) With increase in power

d) None of the mentioned

Answer: a

Explanation: Time of cutting in the laser beam machining process increases with a decrease in cutting speed.

10. In laser beam machining process lens is used to

a) Deflect laser beams

b) Diverge laser beams

c) Converge laser beams

d) None of the mentioned

Answer: c

Explanation: Lens is used to converge a laser beam on a very small area.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Ultrasonic Machining”.

1. Which of the following is an unconventional process of machining?

a) Milling

b) USM

c) Drilling

d) None of the mentioned

Answer: b

Explanation: USM stands for ultrasonic machining process and it is an unconventional process of machining.

2. Ultrasonic machining process can be used for

a) Conductors

b) Insulators

c) Metals

d) All of the mentioned

Answer: d

Explanation: Ultrasonic machining is more versatile and can be used for the metal as well as non metal.

3. Which of the following is a conventional process of machining?

a) Electro chemical machining

b) Electron beam machining

c) Ultrasonic machining

d) None of the mentioned

Answer: d

Explanation: All of the mentioned are unconventional process of machining.

4. For machining of plastic material which of the unconventional process can be used effectively?

a) Electro chemical machining

b) Electron beam machining

c) Ultrasonic machining

d) None of the mentioned

Answer: c

Explanation: Ultrasonic machining is more versatile and can be used for the metal as well as non metal.

5. Material removal rate in USM increases with

a) Decrease in volume of work material per impact

b) Increase in volume of work material per impact

c) Decrease in frequency

d) Decrease in number of particle making impact per cycle

Answer: b

Explanation: Material removal rate in USM is proportional to the volume of work material per impact.

6. Material removal rate in USM increases with

a) Decrease in volume of work material per impact

b) Decrease in volume of work material per impact

c) Decrease in frequency

d) Increase in number of particle making impact per cycle

Answer: d

Explanation: Material removal rate in USM is proportional to the number of particle making impact per cycle.

7. Material removal rate in USM increases with

a) Decrease in volume of work material per impact

b) Decrease in volume of work material per impact

c) Increases in frequency

d) Decreases in the number of particle making impact per cycle

Answer: c

Explanation: Material removal rate in Ultrasonic machining is proportional to frequency.

8. Element of machine which is used to convert high frequency electrical impulse into mechanical vibration in USM is known as

a) Tool

b) Feeding unit

c) Transducer

d) None of the mentioned

Answer: c

Explanation: Transducer is a device which is used to convert one form of energy to other.

9. Which of the following elements of USM is used to apply working force during machining operation?

a) Tool

b) Feeding unit

c) Transducer

d) None of the mentioned

Answer: b

Explanation: Feeding unit is used to apply working force during a machining operation.

10. Material removal rate in USM increases with

a) Decrease in amplitude

b) Decrease in grain size of abrasives

c) Decrease in frequency

d) Increase in amplitude

Answer: d

Explanation: Material removal rate in ultrasonic machining is proportional to amplitude.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Abrasive jet Machining”.

1. Which of the following is an unconventional process of machining?

a) Milling

b) AJM

c) Drilling

d) None of the mentioned

Answer: b

Explanation: AJM stands for abrasive jet machining and it is an unconventional process of machining.

2. Abrasive jet machining process can be used for

a) Conductors

b) Insulators

c) Metals

d) All of the mentioned

Answer: d

Explanation: Abrasive jet machining is more versatile and can be used for the metal as well as non metal.

3. Which of the following is a conventional process of machining?

a) Electro chemical machining

b) Electron beam machining

c) Drilling

d) Abrasive jet machining

Answer: c

Explanation: Drilling is a conventional process of machining.

4. For machining of plastic material which of the unconventional process can be used effectively?

a) Electro chemical machining

b) Electron beam machining

c) Abrasive jet machining

d) None of the mentioned

Answer: c

Explanation: Abrasive jet machining is more versatile and can be used for the metal as well as non metal.

5. Metal removal rate in abrasive jet machining increases with

a) Increase in abrasive flow rate

b) Decrease in abrasive flow rate

c) Decrease in grain size of abrasives

d) Increase in grain size of abrasives

Answer: a

Explanation: Metal removal rate in abrasive jet machining increases with increase in abrasive flow rate. But after certain limit, erosion in nozzle become larger and velocity of grains become smaller.

6. Metal removal rate in abrasive jet machining increases with

a) Increase in abrasive flow rate but decreases beyond a certain limit

b) Decrease in abrasive flow rate

c) Increase in grain size of abrasives

d) None of the mentioned

Answer: a

Explanation: MRR is directly proportional to grain size.

7. Metal removal rate in abrasive jet machining increases with

a) Increase in standoff distance but decreases beyond a certain limit

b) Decrease in abrasive flow rate

c) Decrease in grain size in grain size of abrasives

d) None of the mentioned

Answer: a

Explanation: MRR is directly proportional to standoff distance up to certain limit. After certain limit, kinetic energy of abrasives starts decreasing.

8. Metal removal rate in abrasive jet machining increases with

a) Increase in gas pressure

b) Decrease in abrasive flow rate

c) Decrease in gas pressure

d) None of the mentioned

Answer: a

Explanation: MRR is directly proportional to gas pressure.

9. Mixing ratio in abrasive jet machining is defined as a ratio of

a) Mass flow rate of abrasive to mass flow rate of gas

b) Mass flow rate of gas to mass flow rate of abrasive

c) Velocity of gas to velocity of abrasive

d) None of the mentioned

Answer: a

Explanation: Mixing ratio in abrasive jet machining is defined as a ratio of mass flow rate of abrasive to mass flow rate of gas.

10. High abrasive flow rate decreases the life of nozzle in the abrasive machining process.

a) True

b) False

Answer: a

Explanation: Due to high velocity, erosion starts in a nozzle which further decreases its life.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Other Unconventional Machining”.

1. Which of the following is an unconventional process of machining?

a) Milling

b) WJM

c) Drilling

d) None of the mentioned

Answer: b

Explanation: WJM stands for water jet machining and it is an unconventional process of machining. Water jet machining process is more versatile and can be used for the metal as well as non metal.

2. Water jet machining process can be used for

a) Conductors

b) Insulators

c) Metals

d) All of the mentioned

Answer: d

Explanation: WJM stands for water jet machining and it is an unconventional process of machining. Water jet machining process is more versatile and can be used for the metal as well as non metal.

3. Which of the following is a conventional process of machining?

a) Electro chemical machining

b) Electron beam machining

c) Water jet machining process

d) None of the mentioned

Answer: d

Explanation: All of the mentioned are unconventional machining process. Water jet machining process is more versatile and can be used for the metal as well as non metal.

4. For machining of plastic material which of the unconventional process can be used effectively?

a) Electro chemical machining

b) Electron beam machining

c) Water jet machining process

d) None of the mentioned

Answer: c

Explanation: WJM stands for water jet machining and it is an unconventional process of machining. Water jet machining process is more versatile and can be used for the metal as well as non metal.

5. Decrease in ratio of work hardness to tool hardness decreases material removal rate.

a) True

b) False

Answer: b

Explanation: Ratio of work hardness to tool hardness is inversely proportional to material removal rate.

6. Decrease in viscosity of fluid used decreases material removal rate.

a) True

b) False

Answer: b

Explanation: Viscosity is inversely proportional to the material removal rate. With increase in viscosity, material removal rate decreases.

7. Material removal rate decreases with

a) Increase in amplitude

b) Decrease in grain size of abrasives

c) Increase in frequency

d) Increase in amplitude

Answer: d

Explanation: Material removal rate in USM is proportional to a grain size of abrasives used. No residual stresses are left in ultrasonic machining.

8. Which of the following is correct about USM?

a) Surface finish is bad

b) High cost

c) Not efficient for brittle material

d) None of the mentioned

Answer: d

Explanation: All of the mentioned are not correct about ultrasonic machining.

9. Which of the following is correct about USM?

a) Surface finish is bad

b) High cost

c) Not efficient for brittle material

d) No residual stress on work piece

Answer: d

Explanation: No residual stresses are left in ultrasonic machining. Material removal rate in USM is proportional to grain size of abrasives used.

10. Which of the following is not correct about USM?

a) Low cost

b) Process is very loud noise making

c) Good surface finish

d) None of the mentioned

Answer: b

Explanation: Ultrasonic machining is a very silent process. Material removal rate in USM is proportional to grain size of abrasives used.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Metrology-1”.

1. Maximum deviation in size of shaft or hole is known as

a) Tolerance

b) Fundamental deviation

c) Clearance

d) Interference

Answer: a

Explanation: Tolerance is the maximum deviation in size of shaft or hole.

2. Nearest deviation between hole and shaft from the basic value is known as

a) Tolerance

b) Fundamental deviation

c) Clearance

d) Interference

Answer: b

Explanation: Tolerance is the maximum deviation in size of shaft or hole.

3. When size of the smallest hole is more than size of biggest shaft then it is

a) Clearance fit

b) Interference fit

c) Transition fit

d) None of the mentioned

Answer: a

Explanation: When size of the smallest hole is more than size of biggest shaft then it is clearance fit.

4. Value of minimum clearance is given by

a) Size of smallest hole – size of biggest shaft

b) Size of smallest hole + size of biggest hole

c) Size of smallest shaft – size of biggest shaft

d) None of the mentioned

Answer: a

Explanation: Minimum clearance is the difference between size of smallest hole and size of biggest shaft.

5. Value of maximum clearance is given by

a) Size of smallest hole – size of biggest hole

b) Size of smallest shaft + size of biggest hole

c) Size of smallest shaft – size of biggest shaft

d) None of the mentioned

Answer: b

Explanation: Maximum clearance is given by sum of size of biggest hole and smallest shaft.

6. When size of smallest shaft is more than size of biggest hole then it is

a) Clearance fit

b) Interference fit

c) Transition fit

d) None of the mentioned

Answer: b

Explanation: When size of smallest shaft is more than size of biggest hole then it is interference fit.

7. Value of maximum Interference is given by

a) Size of smallest hole – size of biggest shaft

b) Largest of shaft size hole – smallest hole size

c) Size of smallest shaft – size of biggest shaft

d) None of the mentioned

Answer: b

Explanation: Maximum Interference is the difference between size of largest haft size and smallest hole size.

8. Value of minimum interference is given by

a) Size of smallest hole – size of biggest hole

b) Size of smallest shaft + size of biggest hole

c) Size of smallest shaft – size of biggest hole

d) None of the mentioned

Answer: c

Explanation: Minimum interference is the difference between size of smallest shaft and size of biggest hole.

9. For manufacturing of a certain amount of hole, maximum hole size was found to be 50.14 mm and minimum hole size was found to be 49.98. Tolerance in mm will be

a) 0.12

b) 0.13

c) 0.16

d) 0.20

Answer: c

Explanation: Tolerance is the maximum deviation in size of shaft or hole.

10. In manufacturing of hole and shaft, maximum shaft diameter was 49.88 mm and minimum hole diameter was found to be 49.94 mm. It is a

a) Clearance fit

b) Interference fit

c) Transition fit

d) None of the mentioned

Answer: a

Explanation: When size of smallest hole is more than size of biggest shaft then it is clearance fit.

This set of tricky Manufacturing Engineering Questions & Answers focuses on “Metrology-2”.

1. In an assembly of hole and shaft, smallest hole was having diameter of 49.98 mm and largest shaft was having diameter of 49.94 mm. Minimum clearance in mm will be

a) .08

b) .03

c) .001

d) .04

Answer: d

Explanation: Minimum clearance is the difference between size of smallest hole and size of biggest shaft. Maximum clearance is given by sum of size of biggest hole and smallest shaft.

2. In an assembly of hole and shaft, smallest shaft was having diameter of 49.98 mm and largest hole was having diameter of 50.14 mm. Maximum clearance in mm will be

a) 0.23

b) 0.26

c) 0.32

d) 0.12

Answer: b

Explanation: Maximum clearance is given by sum of size of biggest hole and smallest shaft. Minimum clearance is the difference between size of smallest hole and size of biggest shaft.

3. In an assembly of hole and shaft, largest shaft was having diameter of 50.18 mm and smallest hole was having diameter of 49.98 mm. Maximum interference in mm will be

a) 0.2

b) 0.3

c) 0.3

d) 0.1

Answer: a

Explanation: Maximum Interference is the difference between size of largest haft size and smallest hole size. Minimum interference is the difference between size of smallest shaft and size of biggest hole.

4. In an assembly of hole and shaft, minimum shaft diameter is 49.36 mm and maximum shaft diameter is 48.20 mm. It is an example of

a) Clearance fit

b) Interference fit

c) Transition fit

d) None of the mentioned

Answer: b

Explanation: When size of smallest shaft is more than size of biggest hole then it is

Interference fit. Maximum Interference is the difference between size of largest haft size and smallest hole size.

5. In an assembly of hole and shaft, smallest shaft was having diameter of 50.16 mm and largest hole was having diameter of 50.14 mm. Minimum interference in mm will be

a) 0.2

b) 0.3

c) 0.3

d) 0.1

Answer: a

Explanation: Minimum interference is the difference between size of smallest shaft and size of biggest hole. Maximum Interference is the difference between size of largest haft size and smallest hole size.

6. Maximum material limit of shaft is

a) Maximum diameter of hole

b) Maximum diameter of shaft

c) Smallest diameter of hole

d) Minimum diameter of shaft

Answer: b

Explanation: Maximum material limit of shaft is maximum diameter of shaft. Minimum material limit of shaft is minimum diameter of shaft.

7. Maximum material limit of hole is

a) Maximum diameter of hole

b) Maximum diameter of shaft

c) Smallest diameter of hole

d) Minimum diameter of shaft

Answer: c

Explanation: Maximum material limit of hole is smallest diameter of hole. Minimum material limit of hole is largest diameter of hole.

8. Minimum material limit of shaft is

a) Maximum diameter of hole

b) Maximum diameter of shaft

c) Smallest diameter of hole

d) Minimum diameter of shaft

Answer: d

Explanation: Minimum material limit of shaft is minimum diameter of shaft. Maximum material limit of shaft is maximum diameter of shaft.

9. Minimum material limit of hole is

a) Maximum diameter of hole

b) Maximum diameter of shaft

c) Smallest diameter of hole

d) Minimum diameter of shaft

Answer: c

Explanation: Minimum material limit of hole is largest diameter of hole. Maximum material limit of hole is smallest diameter of hole.

10. Allowance of hole and shaft assembly is equal to

a) Sum of maximum metal limit

b) Product of Maximum limit

c) Difference of maximum metal limit

d) None of the mentioned

Answer: c

Explanation: Allowance of hole and shaft assembly is equal to the difference of maximum metal limit.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Welding Basics-1”.

1. Pinch effect in welding is the result of?

a) Electromagnetic forces

b) Electrostatic forces

c) Magnetic forces

d) Electric forces

Answer: a

Explanation: Pinch effect in welding gives narrow and long flame which is concentrated on the desired part and is achieved by an induction coil, which results in electromagnetic forces.

2. The junction between weld face and base metal is known as?

a) Throat

b) Toe

c) Root

d) Puddle

Answer: b

Explanation: The junction of the weld face and the base metal is known as ‘toe’. For a better weld, the junction should be as small as it can be in size.

3. The junction between two workpieces and weld face is known as?

a) Throat

b) Toe

c) Root

d) Puddle

Answer: a

Explanation: The throat of a weld is the distance from the centre of the face to the root of the weld. Typically, the depth of the throat should be at least as thick as the thickness of the metal we are welding.

4. The portion at which two workpieces are at the nearest distance is called?

a) Throat

b) Toe

c) Root

d) Puddle

Answer: c

Explanation: The weld root is the point at which the back of a weld intersects with the base metal surfaces. It determines the weld penetration and fusion to form a rigid joint.

5. The portion of weld joint that is melted by the heat of melting is called as ______________

a) throat

b) toe

c) root

d) puddle

Answer: d

Explanation: The arc spot or “puddle” weld is started by striking an arc on the deck surface, causing a hole to form in the deck. The weld operation then continues by depositing electrode material on the beam or joist and allowing the molten “puddle” to engage the penetrated deck.

6. Small weld used to temporarily hold the two pieces is called as ______________

a) crater

b) base metal

c) tack weld

d) penetration

Answer: c

Explanation: Tack welds are essentially temporary welds that help to hold two metals in place. The main purpose of the tack weld is to hold the two pieces of metal in place while we apply the actual, final weld.

7. What is the function of a torch?

a) It controls fuel rate

b) It mixes fuel and oxygen and controls delivery

c) It controls oxygen rate

d) It mixes fuel and hydrogen

Answer: b

Explanation: Torch mixes fuel and oxygen and controls delivery. It has two control valves, one for controlling the flow of acetylene and the other of oxygen, entering a chamber called mixing chamber where the two gases are mixed in a correct proportion.

8. The depth up to which, the filler material is mixed up with base metal is called?

a) Deposition

b) Reinforcement

c) Penetration

d) Fusion depth

Answer: c

Explanation: The depth up to which the filler material is mixed up with base metal is called as penetration. Penetration can be increased by increasing temperature and appropriate flux.

9. Weld pass is associated with the movement of __________

a) torch

b) metal

c) flux

d) electrode

Answer: a

Explanation: A single progression of welding or surfacing along a joint or substrate. The result of a pass is a weld bead.

10. The raised potion from the parent metal in welding is known as __________

a) deposition

b) fusion depth

c) penetration

d) reinforcement

Answer: d

Explanation: Weld metal in excess of the quantity required to fill a joint. This can be machined for a good surface finish.

This set of tough Manufacturing Engineering Questions & Answers focuses on “Welding Basics-2”.

1. Which of the following process involves metallurgical fusion?

a) Forming

b) Welding

c) Forging

d) Extrusion

Answer: b

Explanation: Welding joins metals by melting and fusing them together, typically with the addition of a welding filler metal.

2. In welding, two parts are joined by bringing them to a temperature of?

a) Above melting point temperature

b) Below melting point temperature

c) Equal to melting point temperature

d) Equal to Curie temperature

Answer: a

Explanation: In welding one needs to melt the base metals to fuse them.

3. In welding the strength of the joint piece could be?

a) Equal to that of parent metal

b) Greater than that of parent metal

c) Equal or Greater than that of parent metal

d) Is lesser than the parent metal

Answer: c

Explanation: The strength of perfectly welded joint is more than the parent metal, due to the formation of alloy. The alloy formation at the welded portion makes it the strongest portion while the nearby zones where uncontrolled cooling take place because of heat is the weakest zone . In general we can say that on the basis of strength: welded portion > parent material > heat affected zone.

4. Which of the following is a type of welding joint?

a) Tee joint

b) Lap joint

c) Corner joint

d) All of the Mentioned

Answer: d

Explanation:Different types of welding joints are depicted below:

5. The oil substances are removed from the interface by using which of the following organic solvent?

a) Acetone

b) Carbon tetrachloride

c) Acetone & Carbon tetrachloride

d) Ethylene glycol

Answer: c

Explanation: Both acetone and carbon tetrachloride are used to remove the oil substances from the interface.

6. Which of the following does not require fluxes to eliminate the oxides present in them?

a) Mild steel

b) Copper

c) Aluminium

d) Magnesium

Answer: a

Explanation: Mild steel does not require flux to eliminate the oxides, due to the fact that iron oxide has relatively low melting point when compared to other non-ferrous metals given.

7. The heavier oxide films are removed by using?

a) Basic flux

b) Emery

c) Organic solvents

d) Neutral flux

Answer: b

Explanation: Oxide films should be removed before welding. Heavier oxide films may be removed by acid pickling, emery or by wire brusing.

8. In which of the following welding process no filler material is added during joining?

a) Autogenous

b) Homogenous

c) Heterogenous

d) Either homogenous or heterogenous

Answer: a

Explanation: In autogenous welding process no filler material is added during joining, the filler material can be supplied by melting the base metal.

9. Which of the following is a type of autogenous welding?

a) Arc

b) Gas

c) Brazing

d) Resistance

Answer: d

Explanation: Resistance welding is inherently autogenous as there is no convenient way to apply a filler material.

10. In which of the following joining process, the filler material used is the same as the parent material?

a) Autogenous

b) Homogenous

c) Heterogenous

d) Either homogenous or heterogenous

Answer: b

Explanation: In homogenous joining process the filler material used is the same as the parent material.

11. In which of the following joining process the filler material used is different as the parent material?

a) Autogenous

b) Homogenous

c) Heterogenous

d) Either homogenous or heterogenous

Answer: c

Explanation: In heterogenous joining process the filler material used is different as the parent material.

12. Which of the following is a type of homogenous welding?

a) Gas

b) Solid phase

c) Brazing

d) Resistance

Answer: a

Explanation: Gas metal arc welding , manual metal arc welding , flux cored arc welding , etc. always use consumable filler material and thus can be performed in homogenous mode.

13. Which of the following is a type of heterogeneous welding?

a) Gas

b) Solid phase

c) Arc

d) Soldering

Answer: d

Explanation: Certain welding processes such as plasma arc welding, friction stir welding, laser beam welding, etc. can be performed in heterogenous mode.

14. When two insoluble materials such as iron and silver are supposed to join, which of the following joining process is used?

a) Autogenous

b) Homogenous

c) Heterogenous

d) Either homogenous or heterogenous

Answer: c

Explanation: When two insoluble materials such as iron and silver are joined then heterogenous joining process is used.

15. For joining two insoluble materials such as iron and silver which of the following filler material is used?

a) Cobalt

b) Tin

c) Aluminium

d) Zinc

Answer: b

Explanation: Tin is used for joining two insoluble materials such as iron and silver because it is soluble in both the parent material .

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Gas Welding and Gas Cutting”.

1. Which of the following is also called “gas welding”?

a) Oxy fuel gas welding

b) Metallic welding

c) Arc welding

d) Fuel gas welding

Answer: a

Explanation: Gas welding is also known as oxy fuel gas welding. In gas welding, fuel gases are used to generate high amount of heat and melt the metal.

2. How many types of flames are there in welding?

a) 1

b) 2

c) 3

d) 4

Answer: c

Explanation: There are three basic flame types: neutral , excess acetylene , and excess oxygen  as shown below.

3. In which of the following type of flame, oxygen is of same proportion with acetylene?

a) Neutral flame

b) Oxidizing flame

c) Carburizing flame

d) Both oxidizing flame and carburizing flame

Answer: a

Explanation: In neutral flame oxygen is in the same proportion with acetylene. Neutral welding flames are commonly used to weld: mild steel, stainless steel, cast iron, copper, aluminium, etc.

4. In which of the following type of flame, oxygen is in excess proportion with acetylene?

a) Neutral flame

b) Oxidizing flame

c) Carburizing flame

d) Both oxidizing flame and carburizing flame

Answer: b

Explanation: Oxidizing welding flames are produced when slightly more than one volume of oxygen is mixed with one volume of acetylene. Oxidizing welding flames are commonly used to weld zinc, copper, manganese steel, cast iron, etc.

5. In which of the following type of flame, oxygen is deficient in proportion with acetylene?

a) Neutral flame

b) Oxidizing flame

c) Carburizing flame

d) Both oxidizing flame and carburizing flame

Answer: c

Explanation: The carburizing flame has excess acetylene then oxygen. Reducing flame is used for the welding of low carbon and alloy steel.

6. Which of the following flame is harmful to steel?

a) Neutral flame

b) Oxidizing flame

c) Carburizing flame

d) Both oxidizing flame and carburizing flame

Answer: b

Explanation: Oxidizing flame is harmful to steel. An oxidizing flame should not be used for welding steel because the deposited metal will be porous, oxidized and brittle. This flame will ruin most metals and should be avoided.

7. For brazing, soldering and flame hardening which of the following flame is used?

a) Neutral flame

b) Oxidizing flame

c) Carburizing flame

d) Both oxidizing flame and carburizing flame

Answer: c

Explanation: For brazing, soldering and flame hardening carburizing flame is used.

8. The inner cone of the flame in welding has the following nature?

a) Highest temperature

b) Coldest temperature

c) Moderate temperature

d) Uncertain

Answer: a

Explanation: The inner cone of the flame has the highest temperature . The outer flame has the lowest temperature.

9. The oxy acetylene gas welding is a type of?

a) Endothermic reaction

b) Exothermic reaction

c) Neutral reaction

d) Both endothermic reaction and exothermic reaction

Answer: b

Explanation: The oxy acetylene gas welding is a type of exothermic reaction. 1 mole of acetylene can produce KJ/mol of heat.

10. The chemical formula of acetylene is?

a) C 2 H 4

b) C 2 H 6

c) C 2 H 5 OH

d) C 2 H 2

Answer: d

Explanation: The chemical formula of acetylene is C 2 H 2 . 1 mole of acetylene can produce KJ/mol of heat.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Arc Welding”.

1. Amount of time during which the transformer will be used for welding under normal loading condition is known as?

a) Hold time

b) Off time

c) Weld time

d) Duty cycle

Answer: d

Explanation: Amount of time during which the transformer will be used for welding under normal loading condition is known as the duty cycle.

2. Amount of voltage required to generate the arc under no load condition is called?

a) Open circuit voltage

b) Closed circuit voltage

c) Short circuit voltage

d) Arc voltage

Answer: a

Explanation: Amount of current required to generate the arc under no load condition is called short circuit current .

3. Amount of current required to generate the arc under no load condition is called?

a) Open circuit current

b) Closed circuit current

c) Short circuit current

d) Arc current

Answer: c

Explanation: Amount of current required to generate the arc under no load condition is called short circuit current. It is represented by SCC.

4. If the open circuit voltage is 60 volt and the short circuit current is 20 amperes. Then determine the voltage required for welding if the current required during welding is 10 amperes?

a) 30 V

b) 60 V

c) 20 V

d) 40 V

Answer: a

Explanation: Voltage = OCV – 

 

×OCV, where “OCV” is open circuit voltage, “SCC” is short circuit voltage and “I” represents the current in amperes.

5. How does the arc voltage V depends upon the length of arc L?

a) V = f

b) V = 1/f

c) V = f

d) V = f

Answer: a

Explanation: V= A+BL, where ‘V’ is the arc voltage and ‘L’ is the length of arc in cm, A & B are constants.

6. What is the function of flux in submerged arc welding?

a) To completely cover the welded zone

b) To prevent oxidation of joint

c) To prevent spattering of molten metal

d) To prevent sticking of molten metal

Answer: d

Explanation: Flux is used to completely cover the welded zone. It prevents oxidation of weld joint and spattering of molten metal.

7. In which of the following gas welding process a non-consumable electrode is used?

a) Submerged arc welding

b) Tungsten inert gas welding

c) Stud welding

d) Gas metal arc welding

Answer: b

Explanation: In tungsten inert gas welding process a non-consumable electrode is used, which is made of tungsten.

8. What is the only difference between Plasma arc welding and TIG welding?

a) Flux is not used

b) Construction of torch is different

c) Gas is not used

d) Tungsten electrode is not used

Answer: b

Explanation: Construction of the torch is the only difference between Plasma arc welding and TIG welding. Both the TIG and PAW are uses tungsten electrodes.

9. In plasma arc welding the gas is?

a) Ionized

b) Heated

c) Magnetized

d) Vaporized

Answer: a

Explanation: In plasma arc welding the gas is ionized. Electrode used is made of tungsten and filler metal is used addition to it.

10. If the heat transfer efficiency is 0.5 and the melting efficiency is 0.6, then the overall efficiency will be?

a) 0.83

b) 0.03

c) 0.30

d) 0.12

Answer: c

Explanation: ηtotal = ηmelting * ηheat transfer, where η denotes efficiency. There are two types of efficiencies, one is melting efficiency and another is heat transfer efficiency.

11. The deflection of the arc in arc blow is by?

a) Electric field

b) Magnetic field

c) Combination of both

d) Hydrostatic field

Answer: b

Explanation: The deflection of the arc in arc blow is by a magnetic field. Electric field, hydrostatic field does not affect the deflection of the arc.

12. If the total efficiency is 0.35 in arc welding. Then what is the welding speed in mm/sec if the cross-sectional area is 5mm 2 , welding power is 2 kW and the heat required in melting the metal is 100 J/mm 3 .

a) 1.4

b) 14

c) 1400

d) 140

Answer: a

Explanation: N = /, where P represents power, q represents heat transfer, and A represents the cross-sectional area.

13. Which of the following gas welding process uses constant voltage?

a) Submerged arc welding

b) Tungsten inert gas welding

c) Stud welding

d) Gas metal arc welding

Answer: d

Explanation: Gas metal arc welding uses constant voltage. Tungsten inert gas welding does not use constant circuit voltage.

14. Which of the following inert gas is used with DC power supply only?

a) Argon

b) Helium

c) CO 2

d) Nitrogen

Answer: c

Explanation: Co 2 is used only in DC power supply. It cannot be used in AC power supply. Argon and helium can be used with AC supply.

15. In order to prevent oxidation and retain molten metal in stud welding which of the following is used?

a) Ceramic rings

b) Metal rings

c) Non-metal rings

d) Flux

Answer: a

Explanation: In order to prevent oxidation and retain molten metal in stud welding ceramic rings are used.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Resistance Welding-1”.

1. Which of the following is not true about fusion welding?

a) It depends upon the characteristics of heat source.

b) It depends upon the nature of deposition of the filler material

c) It does not depend upon the heat flow characteristics in the joint

d) It depends upon the gas metal or slag metal reaction

Answer: c

Explanation: Fusion welding depends upon the heat flow characteristics in the joint. The quantity of heat required to melt a given volume of metal depends on:  The heat to raise the temperature of the solid metal to its melting point,  The melting point of the metal,  The heat to transform the metal from solid to liquid phase at the melting point.

2. Which of the following is not used to produce heat during welding?

a) Electric arc

b) Chemical flame

c) Electrical resistance

d) Acetone flame

Answer: d

Explanation: For welding heating, different kinds of energy are converted into heat, typically, electrical, beam, chemical and mechanical energy and also their combinations.

3. In which of the following welding process heat and pressure is applied on the joint but no filler material or flux is added?

a) Arc welding

b) Resistance welding

c) Gas welding

d) Thermite welding

Answer: b

Explanation: Resistance welding is the method to joint two plain metal work pieces together by running an electrical current through them. No filler metal and no flux are needed in this type.

4. Total resistance in welding is composed of:

 Resistance of electrode

 Contact resistance between electrode and work piece

 Contact resistance between two work piece plates

 Resistance of work piece

Which of the following is correct?

a) i

b) ii, iii and iv

c) ii and iv

d) I, ii, iii and iv

Answer: d

Explanation: Total resistance is the equivalent resistance of all resistances present in the welding circuit during the process of welding.

5. If 20 amperes of current is flowing in a wire for 1 minute of time having a resistance of 1000 ohm. Then the amount of heat generated in resistance welding will be ?

a) 24000

b) 240000

c) 24000000

d) 2400

Answer: a

Explanation: Heat produced = I 2 RT, where ‘I’ is the current, ‘R’ is resistance and ‘T’ is the time in seconds. For the given problem, heat produced = (20 2 )××

Therefore heat produced = 400 × 1000 × 60 = 24,000 KJ.

6. Which of the following is true about electrodes?

a) Low electrical conductivity and low mechanical strength

b) Low electrical conductivity and high mechanical strength

c) High electrical conductivity and low mechanical strength

d) High electrical conductivity and high mechanical strength

Answer: d

Explanation: To get maximum efficiency, electrodes should have high electrical conductivity and high mechanical strength.

7. Which of the following is true about resistance welding?

a) Electrodes of higher resistivity is used for lower resistive piece

b) Electrodes of higher resistivity is used for higher resistive piece

c) Electrodes of lower resistivity is used for lower resistive piece

d) Electrodes of lower resistivity is used for higher resistive piece

Answer: a

Explanation: To get high efficiency, electrodes of higher resistivity is used for lower resistive piece.

8. According to the joules law?

a) The poor conductor heats up to a higher degree than a good conductor

b) The poor conductor heats up to a lower degree than a good conductor

c) The poor conductor heats up to equal degree than a good conductor

d) Joules law does not relate to heat

Answer: a

Explanation: Joules law relate power with voltage and current as: Power  = Voltage  × Current . It conveys that poor conductor heats up to a higher degree than a good conductor.

9. Which of the following electrode has very high electrical conductivity but low strength?

a) Copper chromium alloys

b) Copper cobalt alloys

c) Copper beryllium alloys

d) Copper cadmium alloys

Answer: d

Explanation: Copper cadmium alloys have very high electrical conductivity but low strength. They produce very less heat during the current flow.

10. Which of the following electrode has low electrical conductivity but high strength?

a) Copper chromium alloys

b) Copper cobalt alloys

c) Copper beryllium alloys

d) Copper cadmium alloys

Answer: a

Explanation: Copper chromium alloys electrode has low electrical conductivity but higher strength. They generate more heat during the current flow.

This set of tough Manufacturing Engineering Questions focuses on “Resistance Welding-2”.

1. Which one of the following is the simplest type of resistance welding used in making lap welds?

a) Resistance spot

b) Resistance seam

c) Projection

d) Upset

Answer: a

Explanation: The simplest form of the process is spot welding for lap welds, where the pressure is provided by clamping two or more overlapping sheets between two electrodes. Up to a thickness of 12.7 mm we can go for it.

2. The time required for electrodes to align and clamp the work piece together under them is known as?

a) Hold time

b) Off time

c) Squeeze time

d) Weld time

Answer: c

Explanation: Squeeze time is the time interval between the initial application of the electrode force on the work and first application of current. Squeeze time is necessary to delay the weld current until the electrode force has attained the desired level.

3. Time of current flow through the work piece till they are heated to require temperature is known as?

a) Hold time

b) Off time

c) Squeeze time

d) Weld time

Answer: d

Explanation: Weld time is the time during which welding current is applied to the metal sheets. The weld time is measured and adjusted in cycles in cycles of line voltage as are all timing functions.

4. Time, when pressure is maintained on the molten metal without electric current, is known as?

a) Hold time

b) Off time

c) Squeeze time

d) Weld time

Answer: a

Explanation: Hold time is the period programmed into the weld controller, typically between the end of weld time and the command to open the electrode.

5. The time after which the pressure is released, and metal piece is removed for next cycle is known as?

a) Hold time

b) Off time

c) Squeeze time

d) Weld time

Answer: b

Explanation: Off time is the time after which the pressure is released, and metal piece is removed for next cycle. It begins automatically after hold time.[/

6. The spot formed between the interface of work piece, when strong current and pressure is applied is known as?

a) Joint

b) Nugget

c) Core

d) Tee

Answer: b

Explanation: The spot formed between the interface of work piece when strong current and pressure is applied is known as a nugget. It may be of any shape.

7. In which of the following welding process disc electrodes are used instead of the cylindrical electrode?

a) Resistance spot

b) Resistance seam

c) Projection

d) Upset

Answer: b

Explanation: In resistance seam welding disc electrodes are used instead of the cylindrical electrode. Disc are rotated for the welding operation.

8. In which of the following operation embossing is required before welding?

a) Resistance spot

b) Resistance seam

c) Projection

d) Upset

Answer: c

Explanation: In projection, welding embossing is required before welding. It is non-productive time used in preparation of welding.

9. In which of the following welding operation the pieces are joined by butt joint?

a) Resistance spot

b) Resistance seam

c) Projection

d) Upset

Answer: d

Explanation: Upset welding or resistance butt welding is a welding technique that produces coalescence simultaneously over the entire area of abutting surfaces or progressively along a joint, by the heat obtained from resistance to electric current through the area where those surfaces are in contact.

10. In which of the following operation it is possible to weld more than one spot at a given time?

a) Resistance spot

b) Resistance seam

c) Projection

d) Upset

Answer: c

Explanation: The advantage of projection welding include flexibility, as the welder can weld more than one spot at a time. Additionally, the welder can position welded spots more closely to each other than is possible with spot welding.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Welding Metallurgy and Welding Defects”.

1. Which of the following defects occur due to flux employed and electrode coating?

a) Inclusion of slag

b) Inadequate penetration

c) Incomplete fusion

d) Porosity

Answer: a

Explanation: Slag inclusions are one of the main weld defects. If we don’t properly clean the slag from a bead, we run the risk of it becoming part of the weld when we run the next bead. A good welder will generally burn it out on the next pass, but if not, there will be a chunk of slag in the bead which leaves a weak spot. Slag inclusions.

2. Which of the following defects occur when the deposited metal is not focused on the root of weld?

a) Inclusion of slag

b) Inadequate penetration

c) Incomplete fusion

d) Porosity

Answer: b

Explanation: Inadequate penetration defects occur when the deposited metal is not focused at the root of weld. Some part of gap remains unwelded due to this defect.

3. Which of the following defects occur when weld metal layer fails to fuse together?

a) Inclusion of slag

b) Inadequate penetration

c) Incomplete fusion

d) Porosity

Answer: c

Explanation: Incomplete fusion defects occur when weld metal layer fails to fuse together. It causes discontinuity in weld zone.

4. Which of the following defects occur due to the entrapment of gas bubbles by the freezing dendrites during the cooling of molten pad?

a) Inclusion of slag

b) Inadequate penetration

c) Incomplete fusion

d) Porosity

Answer: d

Explanation: Referred to as worm holes, these are gas pockets trapped in the weld. A couple of reasons would be from not enough shielding gas in MIG, or moisture in the flux.

5. Which of the following defects occur due to filler material having a different rate of contraction compared to parent metal?

a) Undercut

b) Spatter

c) Cracking in weld metal

d) Cold cracking

Answer: c

Explanation: Weld cracking occurs close to the time of fabrication. Most forms of cracking result from the shrinkage strains that occur as the weld metal cools. It can be of hot cracks types.

6. Which of the following defects occur due to melting or burning away of base metal?

a) Undercut

b) Spatter

c) Cracking in weld metal

d) Cold cracking

Answer: a

Explanation: Undercut is the cardinal sin of welding grasshopper! Cutting into the steel with the force of the arc leaves a cut out groove in the weld. If this is not filled back in with filler metal, it leaves a weld defect which is a weak point that can cause the joint to fail. This can cause property damage, injury and even loss of life.

7. Which of the following defects occur due to scattering of metal around the vicinity of weld?

a) Undercut

b) Spatter

c) Cracking in weld metal

d) Cold cracking

Answer: b

Explanation: Spatters are the droplets of molten material during GAS welding or arc welding. A temperature difference and slag accumulation are the reason of spatter formation. Welding speed is also one of the main causes of spatter. Type of material used and type of welding also decide to spatter density.

8. Which of the following defects occur due to incorrect welding techniques?

a) Undercut

b) Hot cracking

c) Cracking in weld metal

d) Cold cracking

Answer: c

Explanation: Cracking in weld metal defect occur due to incorrect welding techniques. Sometimes cracking may not be visible by naked eyes.

9. Which of the following defect is influenced by sulphur and carbon content of weld metals?

a) Undercut

b) Hot cracking

c) Cracking in weld metal

d) Cold cracking

Answer: b

Explanation: Hot cracks are those that occur at elevated temperatures and are usually solidification related. It is being influenced by sulphur and carbon content of weld metals. Sometimes cracking may not be visible by naked eyes.

10. Which of the following defects occur at a lower temperature?

a) Undercut

b) Hot cracking

c) Cracking in weld metal

d) Cold cracking

Answer: d

Explanation: Cold cracks are those that occur after the weld metal has cooled to room temperature and may be hydrogen related. These occurs are lower temperature. Sometimes cracking may not be visible by naked eyes.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Manufacturing Engineering Questions & Answers – Fusion Welding Processes-1”.

1. Consider a situation in which a welding operation is being performed with V = 20 volts, I = 200 A, and the cross-sectional area of the weld bead is 30 mm 2 . Estimate the welding speed if the workpiece and electrode are made of  aluminum,  carbon steel, and  titanium. Use an efficiency of 75%.

a) 35 mm/s

b) 34.5 mm/s

c) 36 mm/s

d) 46 mm/s

Answer: b

Explanation: For aluminum, the specific energy required is u = 2.9 J/mm 3

Therefore,

v = e

=  [/] = 34.5 mm/s.

2. Upon which of the following parameters does the current intensity in arc welding depend?

a) Stability of arc

b) Electrode diameter

c) Gap between the electrode and parent metals

d) Thickness of parent metals

Answer: b

Explanation: Electrodes for consumable arc-welding processes are classified according to the following properties:

i) Strength of the deposited weld metal

ii) Current 

iii) Type of coating.

3. In which of the following welding processes we use two non-consumable electrodes?

a) MIG

b) TIG

c) Atomic hydrogen

d) Submerged arc

Answer: c

Explanation: Non consumable electrodes are the ones that are not consumed during the process of welding. GTAW /TIG , AHW , CAW  processes use non-consumable electrodes.

4. Which of the following brazing process is good for mass scale joining?

a) Furnace

b) Induction

c) Dip

d) Torch

Answer: a

Explanation: Furnace brazing is a semi-automatic used widely in industries and are best suited to large scale production operations.

5. For grey cast iron, which of the following welding methods is preferable?

a) MIG

b) Submerged arc

c) Gas flame

d) Electric arc

Answer: a

Explanation: As the percentage of carbon in grey cast iron is less, therefore MIG welding is preferable.

6. Due to which of the following reasons, flux is not used in atomic hydrogen welding?

a) The burning hydrogen shields the molten metal

b) Two electrodes are coated which gradually release the flux

c) The filler rod is coated with flux

d) One of the two electrodes is coated which releases the flux

Answer: a

Explanation: Separate flux/ shielding gas is not required in atomic hydrogen welding. The hydrogen envelop itself prevents oxidation of the metal and the tungsten electrode.

7. In resistance welding, between the electrodes, the nature of current and voltage parameters being used?

a) high current, high voltage

b) low current, high voltage

c) low current, low voltage

d) high current, low voltage

Answer: d

Explanation: High current produces more heat. When we use a low voltage power source, it allows a welder to have some reasonable over the small lighting bolts we use to fuse metal together.

8. Which of the following welding process in which heat is produced for welding by a chemical reaction?

a) Resisting welding

b) Thermit welding

c) Forge welding

d) Gas welding

Answer: b

Explanation: The thermite process is a chemical reaction in which a metal oxide  is displaced by another molten metal which is more reactive than the metal in the metal oxide, releasing a lot of heat. Example:

2Al + Fe 2 O 3 → Al 2 O 3 + 2Fe

2Fe + Cr 2 O 3 → Al 2 O 3 + 2Cr

Here aluminium is more reactive than Iron and Chromium and displaces it from their oxides. This reaction is used commercially to weld broken metallic parts. Railway lines are joined in the same manner.

9. The maximum diameter of electrodes being used in submerged arc welding?

a) 30 mm

b) 20 mm

c) 15 mm

d) 10 mm

Answer: d

Explanation: A consumable electrode can be used by the submerged arc welding which is a loop of bare round wire with 1.5 mm to 10 mm diameter. It can be fed routinely throughout the welding gun, and the submerged arc welding electrode composition depends on the welded material.

10. In arc welding, arc is created between the electrode and work by?

a) Contact resistance

b) Flow of voltage

c) Flow of current

d) Electrical energy

Answer: d

Explanation: All arc welding utilizes the transfer of electrical energy to heat energy. An arc is a sustained electric discharge through this ionised gas column called plasma between the two electrodes. In order to produce the arc, the potential difference between the two electrodes  should be enough to allow them to move across the air gap. The larger air gap requires higher potential differences. If the air gap becomes too large for the voltage, the arc may be extinguished.

11. The coating material used for the electrode is termed as?

a) Flux

b) Slag

c) Protective layer

d) Deoxidiser

Answer: a

Explanation: Flux is a substance used to prevent the formation of oxides and the other unwanted contaminations, or to dissolve them and facilitate removal. During welding the flux melts and becomes a liquid slag, covering the operation and protecting the molten weld metal the slag hardens upon cooling and must be removed later by chipping or brushing.

12. Which of the following welding process in which two pieces to be joined are overlapped and placed between two pointed electrodes?

a) Seam welding

b) Resistance welding

c) Projection welding

d) Spot welding

Answer: d

Explanation: Spot welding is the simplest and most used resistance welding process. Welding may be performed by means of single  or multiple pairs of electrodes , and the required pressure is supplied through mechanical or pneumatic means.

13. Which of the following gases are used in Tungsten inert gas welding?

a) Helium and neon

b) Hydrogen and oxygen

c) Argon and helium

d) Carbon dioxide and hydrogen

Answer: c

Explanation: In the TIG welding process the arc is formed between a pointed tungsten electrode and the workpiece in an inert atmosphere of argon or helium.

14. Which of the following materials necessitates preheating in welding?

a) Copper

b) Aluminium

c) Cast iron

d) Stainless steel

Answer: c

Explanation: As the weldability of cast iron usually decreases as the amount of free carbon in cast iron increases, so it is preheated to a dull red and then welded.

15. The temperature, in arc welding, is of the order of?

a) 30000°C

b) 55000°C

c) 20000°C

d) 70000°C

Answer: c

Explanation: One of the main functions of the arc is to produce heat. The heat of the arc melts the surface of the base metal and the end of the electrode. The electric arc has a temperature that ranges from 3000 to 20,000°C.

This set of Manufacturing Engineering Puzzles focuses on “Fusion Welding Processes-2”.

1. Which of the following is used to generate Acetylene gas?

a) Calcium

b) Carbon

c) Calcium carbonate

d) Calcium carbide

Answer: d

Explanation: Acetylene is a hydrocarbon consisting of two carbon atoms and two hydrogen atoms. The simplest process reacts calcium carbide with water to produce acetylene gas and a calcium carbonate slurry, called hydrated lime. The chemical reaction may be written as CaC 2 + 2H 2 O → C 2 H 2 + Ca  2 .

2. Striking voltage as compared to a voltage during arc welding is?

a) less

b) same

c) more

d) can’t say

Answer: c

Explanation: The minimum voltage enough to arc across a given gap is called as the striking voltage. It is more than the arc voltage in arc welding.

3. How many zones are there in a carburising flame?

a) one

b) two

c) three

d) four

Answer: c

Explanation: If the oxygen is insufficient for full combustion, the flame is known as a reducing, or carburizing, flame. The temperature of a reducing flame is lower; hence, such a flame is suitable for applications requiring low heat, such as brazing, soldering, and flame-hardening operations.

4. Due to which of the following reasons distortion in welding occurs?

a) Oxidation of weld pool

b) Use of high voltage

c) Improper clamping

d) Use of high current

Answer: c

Explanation: As if the clamping is improper the weld will not be at the right place.

5. In reverse polarity welding _____________

a) work piece is connected as negative, and holder is earthed

b) electrode holder is connected to negative and work piece to positive

c) electrode holder is connected to positive and work piece to negative

d) both electrode holder and work piece are connected to negative

Answer: c

Explanation: In direct current reverse polarity  or direct current electrode positive , when base metals relate to the negative terminal of the power source and electrode relates to the positive terminal.

6. Where does maximum flame temperature occur?

a) Next to inner cone

b) At the inner cone

c) At the tip of the flame

d) At the outer cone

Answer: b

Explanation: Maximum flame temperature occur at inner cone. As flame moves from inner to outer temperature drop takes places.

7. In which of the following welding processes, electrode gets consumed?

a) TIG welding

b) Resistance welding

c) Thermit welding

d) Arc welding

Answer: d

Explanation: As in arc welding, welding is totally dependent on electrode, so it will be consumed.

8. Which of the following statements about welding is incorrect?

a) Increased corrosion resistance

b) Even materials like stainless steel and aluminium can be welded

c) No flux required

d) High welding speed

Answer: c

Explanation: Flux is mainly used for the following purposes:  It prevents the oxidation o the surface of the weld which can contaminate the welded potion,  It helps in forming alloy at the welded portion which improves the strength,  In arc welding the flux coating helps in directing the spark that’s why the electrode is kept concave in shape so that spark can be precisely directed towards the cavity where welding has to be performed.

9. Where is half corner weld used?

a) where efficiency of the joint should be 50 percent

b) where longitudinal shear is present

c) where severe loading is encountered, and the upper surfaces of both pieces must be in the same plane

d) For welding materials heavier than 12 gauge

Answer: d

Explanation: The half-open corner joint is used for welding materials heavier than 12 gauge.

10. Which of the following percentage of carbon in steel is most weldable?

a) 0.15

b) 0.25

c) 0.35

d) 0.8

Answer: a

Explanation: Low carbon steel is typically the most readily welded steel in a room temperature environment.

11. In which of the following metals does the phenomenon of ‘weld decay’ occurs?

a) stainless steel

b) cast iron

c) carbon steel

d) bronze

Answer: a

Explanation: Weld decay is a form of intergranular corrosion, usually of stainless steels or certain nickel-base alloys, that occurs as the result of sensitization in the heat-affected zone during the welding operation.

12. On which of the following principles does the ‘positive pressure type torch’ work?

a) equal volume

b) positive pressure

c) equal pressure

d) equal flow

Answer: c

Explanation: There are two types of welding and cutting torches commonly used. They are the positive-pressure type , and the injector type.

13. Why is post cleaning necessary at brazed joint?

a) to avoid corrosion

b) to avoid slagging

c) to avoid oxidation

d) to avoid scaling

Answer: a

Explanation: Depending on the brazing process, we may need to perform post-braze joint cleaning to remove residual flux. This step is crucial for several reasons; including the corrosive nature of most fluxes and the possibility that excess flux could contribute to joint failure. The most common cleaning methods involve water-specifically soaking/wetting and quenching.

14. While welding, which of the following material welding, neutral flame is not used?

a) cast iron

b) steel

c) copper

d) zinc

Answer: d

Explanation: The neutral flame has a one-to-one ratio of acetylene and oxygen. A neutral flame is named neutral since in most cases will have no chemical effect on the metal being welded. Neutral welding flames are commonly used to weld: mild steel, stainless steel, cast iron, copper, aluminium, etc.

15. Which of the following statements about “projection welding” is correct?

a) It is multi spot welding process

b) It is an arc welding process

c) It is a continuous spot-welding process

d) It is a process used for joining round bars

Answer: a

Explanation: Projection welding is a modification of spot welding in which the weld is localized by means of raised sections, or projections, on one or both workpieces to be joined. This is high-production process, and multiple projection welds can be arranged by suitable designing and jigging.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Unconventional Welding Methods”.

1. In which welding process the electric energy required for welding is stored in the capacitor?

a) Percussion welding

b) Explosion welding

c) Diffusion welding

d) Thermit welding

Answer: a

Explanation: In percussion welding, two pieces are welded by a high intensity short duration arc followed by very rapid or percussive impacting of the workpieces. There are three different methods of arc initiation in percussion welding viz., low voltage with drawn arc, high voltage breakdown, and ionising by a fusing tip. With each method, the energy source is a bank of capacitors which is charged by a variable voltage transformer cum rectifier unit.

2. In which welding process pressure is applied by detonating a layer of explosive?

a) Percussion welding

b) Explosion welding

c) Diffusion welding

d) Thermit welding

Answer: b

Explanation: In explosion welding, a compression force created by detonation of explosives is used to join overlapping metal sheets. The joining parts are arranged toward each other at an angle of 1-15°, depending on the material and method, and are prepared with a layer of explosive on the top.

3. In which welding the surfaces of two components are subjected to static normal force and oscillating shear stress?

a) Diffusion welding

b) Thermit welding

c) Laser beam welding

d) Ultrasonic welding

Answer: d

Explanation: In ultrasonic welding , the faying surfaces of the two members are subjected to a static normal force and oscillating shearing  stresses. The shearing stresses are applied by the tip of a transducer similar to that used for ultrasonic machining.

4. In which welding the strength of the weld results due to diffusion and plastic deformation of the flying surface?

a) Diffusion welding

b) Thermit welding

c) Laser beam welding

d) Ultrasonic welding

Answer: a

Explanation: In diffusion welding, the bond strength is achieved by pressure, temperature, time of contact, and cleanness of the surfaces. The strength of the bond is primarily due to diffusion rather than any plastic deformation.

5. In Thermit welding the heat generated is due to the mixing of?

a) Aluminum and copper

b) Aluminum and iron

c) Aluminum oxide and iron

d) Aluminum and iron oxide

Answer: d

Explanation: Thermite welding is a welding process in which the workpiece is joined with the help of molten metal by means of an exothermic reaction. Thermite mixture consists of a metal oxide  and aluminum powder. The major application of thermite welding is to weld railway tracks. It is also used to weld heavy machinery.

6. Which of the following welding is also known as arc and gas welding?

a) Electro slag welding

b) Atomic hydrogen welding

c) Laser beam welding

d) Ultrasonic welding

Answer: b

Explanation: Atomic hydrogen welding, also known as AHW, is an arc welding technique that uses an arc which is located between two tungsten electrodes and a hydrogen shielding gas.

7. Which of the following welding is used for welding vertical section in one pass?

a) Electro slag welding

b) Atomic hydrogen welding

c) Laser beam welding

d) Electro gas welding

Answer: d

Explanation: Electro gas welding  is an vertical positioned arc welding process, is used for welding the edges of sections vertically and in one pass with the pieces placed edge to edge .

8. Electron beam welding is carried in?

a) Inert atmosphere

b) Partially filled chamber

c) Vacuum

d) Partially vacuum

Answer: c

Explanation: In electron beam welding process, electrons are emitted from the heated filament called electrode. This is done under vacuum conditions to prevent dissipation of the electron beam.

9. Which of the following welding process the weld joint is obtained by means of filler material and not by melting?

a) Diffusion welding

b) Thermit welding

c) Electroslag welding

d) Brazing

Answer: d

Explanation: A brazed joint is made in a completely different manner from welded joint. The big difference is in temperature-brazing does not melt the base metals. This means that brazing temperatures are invariably lower than the melting points of the base metals. It joins base metals by creating a metallurgical bond between the filler metal and the surfaces of the two metals being joined. The principle by which the filler metal is drawn through the joint to create this bond is capillary action.

10. Which of the following statements is not true?

a) Brazing occurs at a temperature above 450°C

b) Soldering occurs at a temperature below 450°C

c) Epoxy resins are used to join metals, ceramics etc

d) Epoxy resins are not used to join metals, ceramics etc

Answer: d

Explanation: The excellent adhesive properties of epoxy resins are due to the attractive forces between the epoxy resin and the surface of the substrate. Typical epoxy resins have pendant hydroxyl  groups along their chain which can form bonds or strong polar attractions to oxide or hydroxyl surfaces. Most inorganic surface, i.e., metals, minerals, glasses, ceramics, etc. have polarity so they have high surface energy. Organic polymer surfaces are generally less polar  thus lower surface energy.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Powder Metallurgy Operation”.

1. Porous product can be effectively produced using powder metallurgy.

a) True

b) False

Answer: a

Explanation: Porosity is simply the empty space in the product material. The production of highly porous parts by powder metallurgy using suitable spacer materials is a well-established technique for titanium and stainless steel.

2. What is the dimensional accuracy in powder metallurgy?

a) High

b) Medium

c) Low

d) Sometimes high and sometimes low

Answer: a

Explanation: The powder metallurgy process yields net-shape, r near-net-shape parts, so that little or no machining is required to obtain a finished part in many cases. Thus, the process offers dimensional tolerances and mechanical properties compatible with many applications.

3. Wastage of material in powder metallurgy as scrap is ____________

a) large

b) small

c) depends on other factors

d) medium

Answer: b

Explanation: Due to the fact that, powder metallurgy giving us near net shapes, thus less machining is required for final product, so less wastage of material as scrap.

4. Complex shape can be formed effectively using?

a) Powder metallurgy

b) Turning

c) Sand casting

d) Metal casting

Answer: a

Explanation: Powder metallurgy allows us to create high-quality components, while near-net-shape dimensional control provides a high degree of control over the manufacturing process, facilitating the production of complex shapes.

5. In powder metallurgy, range of particle size  is?

a) 4 to 200

b) 0.300 to 0.003

c) 100 to 2000

d) 5000 to 6000

Answer: a

Explanation: Range of particle size in powder to be used for powder metallurgy should vary from 4 microns to 200 microns. Powder metallurgy has small wastage of material.

6. Process of forming metal powder by directing molten metal through an orifice after which it is break into small particle using high pressure fluid is known as?

a) Atomization

b) Reduction

c) Crushing

d) Electrolysis

Answer: a

Explanation: The disintegration of a molten metal into particles by a rapidly moving gas or liquid stream or by other means is known as atomization.

7. Formation of metal powder to use in powder metallurgy by reducing some compound with CO or other molecules is known as?

a) Atomization

b) Reduction

c) Crushing

d) Electrolysis

Answer: b

Explanation: Reduction is the process of formation of metal powder to use in powder metallurgy by reducing some compound with CO or other reducing agents.

8. Production of pure powder of iron and copper can be effectively done using?

a) Atomization

b) Reduction

c) Crushing

d) Electrolysis

Answer: d

Explanation: Copper is the primary metal produced by electrolysis, but iron, chromium, and magnesium powders are also produced this way. Due to its associated high energy costs, electrolysis is generally limited to high-value powders such as high-conductivity copper powders.

9. Powder of various and non-ferrous material which becomes brittle on heating, can be formed using?

a) Atomization

b) Reduction

c) Crushing

d) Electrolysis

Answer: c

Explanation: Ferrous and non-ferrous metals are heated first, and when they become brittle, they are crushed. If copper is heated to red heat and cooled slowly it becomes brittle.

10. Sintering is done to _____________

a) increase final strength

b) decrease final strength

c) initially increase and then to decrease the strength

d) initially decrease and then to increase the strength

Answer: a

Explanation: Sintering is a heat treatment commonly used to increase the strength and structural integrity of a material. Powder metallurgy use sintering to convert metal powders to end-use parts.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “NC Part Programming-1”.

1. Which of the following code will give point to point movement?

a) G00

b) G01

c) G56

d) G94

Answer: a

Explanation: G00 will give point to point movement.

2. Which of the following code will give linear interpolation movement?

a) G00

b) G01

c) G78

d) G65

Answer: b

Explanation: G01 will give linear interpolation movement.

3. Which of the following code will give circular interpolation in a clockwise direction?

a) G56

b) G01

c) G02

d) G47

Answer: c

Explanation: G02 will give circular interpolation in a clockwise direction.

4. Which of the following code will give circular interpolation in Counterclockwise direction?

a) G00

b) G56

c) G69

d) G03

Answer: d

Explanation: G03 will give circular interpolation in Counterclockwise direction.

5. Which the following code will produce dwell for a specified time?

a) G18

b) G65

c) G45

d) G04

Answer: d

Explanation: G04 will produce dwell for a specified time.

6. Which of the following code is used to give input of cutter offset data?

a) G30

b) G20

c) G10

d) G04

Answer: c

Explanation: G10 is used to give input of cutter offset data.

7. Which of the following code is used to select x y plane in milling?

a) G18

b) G17

c) G10

d) G04

Answer: b

Explanation: G17 is used to select x y plane in milling.

8. Which of the following code is used to select x z plane in milling?

a) G18

b) G17

c) G10

d) G04

Answer: a

Explanation: G18 is used to select x z plane in milling.

9. Which of the following code is used to select y-z plane in milling?

a) G32

b) G00

c) G02

d) G19

Answer: d

Explanation: G19 is used to select y-z plane in milling.

10. Which of the following code will change specified input values in millimeters?

a) G01

b) G00

c) G20

d) G20

Answer: c

Explanation: G20 will change specified input values in millimeters.

This set of Manufacturing Science online test focuses on “NC Part Programming-2”.

1. Which of the following code is used to return to a reference point?

a) G23

b) G28

c) G14

d) G19

Answer: b

Explanation: G28 is used to return to a reference point.

2. Which of the following code is used in thread cutting in turning?

a) G32

b) G89

c) G20

d) G74

Answer: a

Explanation: G32 is used in thread cutting in turning.

3. Which of the following code is used to cancel offset compensation for cutter radius?

a) G40

b) G02

c) G42

d) G00

Answer: a

Explanation: G40 is used to cancel offset compensation for cutter radius.

4. Which of the following code is used to give cutter offset compensation, left of a part surface?

a) G40

b) G41

c) G42

d) G50

Answer: b

Explanation: G41 is used to give cutter offset compensation, left of part surface.

5. Which of the following code is used to give cutter offset compensation, right of a part surface?

a) G00

b) G41

c) G42

d) G91

Answer: c

Explanation: G42 is used to give cutter offset compensation, right of part surface.

6. Which of the following code is used to specify the location of co-ordinate Axes system origin relative to starting location of cutting tool?

a) G01

b) G41

c) G00

d) G50

Answer: d

Explanation: G50 is used to specify the location of co-ordinate Axes system origin relative to starting location of cutting tool.

7. Which of the following code is used in programming in absolute coordinates?

a) G90

b) G32

c) G92

d) G01

Answer: a

Explanation: G90 is used in programming in absolute coordinates.

8. Which of the following code is used in programming in incremental coordinates?

a) G90

b) G91

c) G92

d) G94

Answer: b

Explanation: G91 is used in programming in incremental coordinates.

9. Which of the following code is used to specify location of co-ordinate Axis System origin relative to starting location of cutting tool?

a) G17

b) G91

c) G92

d) G00

Answer: c

Explanation: G92 is used to specify location of co-ordinate Axis System origin relative to starting location of cutting tool.

10. Which of the following code is used to specify feed per minute in milling and drilling?

a) G69

b) G10

c) G00

d) G94

Answer: d

Explanation: G94 is used to specify feed per minute in milling and drilling.

11. Which of the following code is used to specify feed per revolution in milling and drilling?

a) G24

b) G23

c) G95

d) None of the mentioned

Answer: c

Explanation: G95 is used to specify feed per revolution in milling and drilling.

12. Which of the following code is used to specify feed per minute in turning?

a) G25

b) G98

c) G24

d) G23

Answer: b

Explanation: G98 is used to specify feed per minute in turning.

13. Which of the following code is used to specify feed per revolution in turning?

a) G99

b) G98

c) G78

d) G45

Answer: a

Explanation: G99 is used to specify feed per revolution in turning.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Casting Terms”.

1. The lower molding flask is also known as?

a) Drag

b) Cope

c) Check

d) Chill

Answer: a

Explanation: Cope and Drag refer to the two halves  of a Pattern or Mold that is used in the green sand-casting method.

2. Which of the following is an entry point through which molten metal enters mould cavity?

a) Gate

b) Chaplet

c) Chill

d) Riser

Answer: a

Explanation: Gating system refers to all the sections through which the molten metal while entering the mould cavity. We pour the molten metal through the pouring cup, the molten metal flows into this sprue, the vertical passes. Then, it falls into the sprue well, then it passes through the runner, the horizonal passes, then it passes through the gate.

3. A small funnel shaped cavity at the top of the mould into which the metal is poured is known as?

a) Sprue

b) Core

c) Pouring basin

d) Gate

Answer: c

Explanation: In metal casting, a basin on top of a mold that receives the molten metal before it enters the sprue or downgate is known as pouring basin.

4. Which of the following is used to support the cavity from inside?

a) Chill

b) Chaplet

c) Sprue

d) Core

Answer: b

Explanation: Chaplet is a metal support that holds a core in place within a casting mold; molten metal solidifies around a chaplet and fuses it into the finished casting.

5. The riser is a reservoir of molten metal provided in the casting so that hot metal can flow back into the mould cavity when there is a reduction in the volume of metal due to?

a) Compression

b) Solidification

c) Expansion

d) Melting

Answer: b

Explanation: Riser is a reservoir of molten metal provided in the casting so that hot metal can flow back into the mould cavity when there is a reduction in the volume of metal due to solidification.

6. The passageways in the parting plane through which molten flow is regulated is known as?

a) Core

b) Chaplet

c) Gate

d) Runner

Answer: d

Explanation: Runners are passages that distribute molten metal from the sprue to gates or risers around the cavity inside a mold.

7. The channel through which metal or plastic is poured into a mould?

a) Sprue

b) Gate

c) Flask

d) Riser

Answer: a

Explanation: The passageway in the parting plane through which molten flow is regulated is known as sprue. It may be used to control the flow of metal in mould cavity.

8. The replica of the final object to be made is known as?

a) Parting line

b) Flask

c) Pattern

d) Mould

Answer: c

Explanation: A pattern is a replica of our product. It can be made of wood, metal or plastic. It is used to design and prepare the die. To make our product we need to have something in which we can pour our material for the required shape. That something is called as mould which has the shape of our product.

9. Which of the following term can be used to describe flask?

a) Drag

b) Cope

c) Check

d) Chill

Answer: d

Explanation: Drag is situated at lower molding flask, cope is situated at upper molding flask, check is situated at intermediate molding flask.

10. Which of the following is made of wood?

a) Gate

b) Riser

c) Bottom board

d) Chill

Answer: c

Explanation: A chill is an object used to promote solidification in a specific portion of a metal casting mold. Normally the metal in the mold cools at a certain rate relative to thickness of the casting. When the geometry of the molding cavity prevents directional solidification from occurring naturally, a chill can be strategically placed to promote it.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Fundamentals of Casting”.

1. If we decrease the freezing range, then the fluidity of metal will?

a) Increase

b) Decrease

c) Will not change

d) Initially increase and then decrease

Answer: a

Explanation: Fluidity is inversely proportional to the freezing range. Thus, the shorter the range , the higher the fluidity becomes. Conversely, alloys with long freezing ranges  have lower fluidity.

2. According to Chvorinov’s rule the solidification time is a function of volume and surface area and is given by the relationship between volume, area and some exponential power ‘n’. What is the value of n?

a) 1

b) 2

c) 3

d) 4

Answer: b

Explanation: Chvorinov’s rule states that: t s = \

 

^n\), where t s is the time of solidification, v = volume, A = surface area, n = 1.5 to 2 and B is a constant for metal cast, mold material and casting conditions.

3. Which one of the following expands during solidification?

a) Mild steel

b) Grey cast iron

c) Aluminium

d) Copper

Answer: b

Explanation: Grey cast iron expands upon solidification, as graphite has a relatively high specific volume and it precipitates as graphite flakes during solidification, it causes a net expansion of the metal.

4. Dissolved gases may be removed from molten metal by?

a) Flushing or purging with inert gas

b) Melting and pouring the metal in vacuum

c) Flushing or purging with inert gas or Melting and pouring the metal in vacuum

d) Melting and pouring the metal in nitrogen atmosphere

Answer: c

Explanation: Dissolved gases may be removed from molten metal either by flushing or purging with inert gas or melting and pouring the metal in vacuum.

5. Doubling the time in flat mould will increase the thickness of wall skin by what percentage?

a) 31.6%

b) 41%

c) 73%

d) 22%

Answer: b

Explanation: Thickness is proportional to √ time. When time is doubled in flat mould, thickness of wall skin will increase by 41%.

6. Solidification of casting does not depend upon which factor?

a) Type of metal

b) Thermal properties of metal

c) Geometric relationship between volume and surface area

d) Surface tension

Answer: d

Explanation: Surface tension is a fluid property and solidification time of casting does not depend upon any fluid property.

7. The following characteristic of molten metal influence the fluidity.

i) Mushy zone

ii) Viscosity

iii) Surface tension

iv) Inclusion

Which one of the following is correct?

a) i and ii

b) i only

c) i, ii and iii

d) i, ii, iii and iv

Answer: d

Explanation: All the above mention characteristics influence fluidity. Fluidity in casting is used to designate the casting material ability to fill the mould cavity.

8. What is the function of cores used in casting?

a) To remove dissolved gases

b) To avoid defects

c) To form hollow region

d) To reduce shrinkage porosity

Answer: c

Explanation: Cores form internal cavities inside the structure which will then leads to the final casting shape with hollow structure. Sand inside cores and pattern gives strength and rigidity to the casting structure.

9. Which one of the statements is not correct in metal casting?

a) Rapid cooling produces a solidified skin or shell

b) Those grain that have favourable orientation will grow preferentially

c) Cast iron has wide mushy zones

d) Lack of uniformity in grains size and distribution will cause anisotropic properties

Answer: c

Explanation: Cast iron has low range of mushy zone. Rapid cooling produces a solidified skin or shell and Lack of uniformity in grains size and distribution will cause anisotropic properties.

10. Assertion : Chills are used to reduce shrinkage porosity.

Reason : the function of chill is to increase the rate of solidification in a critical region.

a) Both A and R is correct, and R is a correct explanation for A

b) Both A and R is correct, and R is an incorrect explanation for A

c) A is wrong but R is correct

d) A is correct but R is wrong

Answer: a

Explanation: Chills are used to reduce shrinkage porosity and the function of chill is to increase the rate of solidification in critical region.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Pattern and Allowances”.

1. The allowance provided to take care of the contraction of casting is known as?

a) Draft allowance

b) Shrinkage allowance

c) Machining allowance

d) Shake allowance

Answer: b

Explanation: Most metals contract or shrink volumetrically on cooling. The solid-state shrinkage refers to the reduction in volume caused metal loses temperature in solid state. To account for this, shrinkage allowance is provided on the patterns.

2. Which one of the following statement is not true regarding Contraction?

a) Contraction of liquid takes place from the pouring temperature to the freezing temperature

b) Contraction is associated with the change of phase from liquid to solid

c) Contraction of solid is from the freezing temperature to the room temperature

d) Contraction is not associated with the change of phase from liquid to solid

Answer: d

Explanation: As most metals contact during solidification, this contraction can happen at two stages. The liquid stage refers to the reduction in volume when the metal changes from liquid state to solid state at the solidus temperature. To account for this shrinkage; riser; which feed the liquid metal to the casting, are provided in the mold. To compensate the solid state shrinkage, shrinkage allowance is provided on the patterns.

3. While calculating the linear dimension of a material, shrinkage allowance is always?

a) Added

b) Subtracted

c) Multiplied

d) Divided

Answer: a

Explanation: While calculating the linear dimension of a material shrinkage allowance is always added. The allowance provided to take care of the contraction of a casting is known as shrinkage allowance. During solidification of casting, volume decreases and hence contraction occurs.

4. Which one of the following is a negative allowance?

a) Draft allowance

b) Shrinkage allowance

c) Shake allowance

d) Machining allowance

Answer: c

Explanation: All metals shrink when cooling except perhaps bismuth. This is because of the inter-atomic vibrations which are amplified by an increase in temeprature. The shrinkage allowance is always to be added to the linear dimensions. Even in case of internal dimensions.

5. Which one of the following is not used to make patterns?

a) Wood

b) Plastics

c) Metals

d) Ceramics

Answer: d

Explanation: There are different types of pattern materials: 1. wood pattern , 2. metal pattern , 3. Plastic pattern , 4. wax patterns .

6. Which one of the following will not give good dimensional accuracy in the presence of moisture?

a) Wood

b) Plastics

c) Metals

d) Ceramics

Answer: a

Explanation: Wood absorbs moisture as a result of which the dimension changes. To compensate such losses some allowance should be given.

7. The choice of pattern material depends upon:

i. On size of casting

ii. Number of casting to be made from pattern

iii. Dimensional accuracy

Which of the following is correct?

a)  and 

b)  only

c) ,  and 

d)  and 

Answer: c

Explanation: All the statements are correct about pattern materials. The choice of pattern material depends upon on size of casting, number of casting to be made from the pattern, dimensional accuracy.

8. In order to reduce the chances of damage due to withdrawing of a pattern from the mould is done by giving ________

a) Draft allowance

b) Shrinkage allowance

c) Distortion allowance

d) Shake allowance

Answer: a

Explanation: While removing the pattern from the mould, the parallel surface to the direction at which pattern being withdrawn has a chance of getting damaged. The draws allowance will allow this easy removal of pattern from the old and does not affect the actual dimension of casting.

9. To have good surface finish and accuracy which of the allowance is given?

a) Draft allowance

b) Shrinkage allowance

c) Shake allowance

d) Machining allowance

Answer: d

Explanation: The necessity of machining allowance is as follows: 1. for removing surface roughness, slag, dirt and other imperfections form the casting, 2. For obtaining exact dimensions on the casting, 3. To achieve desired surface finish on the casting.

10. For good dimensional tolerances and smooth surface which of the following is used as pattern material?

a) Wood

b) Plastics

c) Metals

d) Ceramics

Answer: c

Explanation: The primary benefits of using ceramic patterns are as follows: 1. It is a reusable pattern, 2. close dimensional accuracy, 3. excellent surface finish. There are two types of ceramic mold casting known as the “unicast process” and the “shaw process”.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Moulding sand”.

1. Which of the following is not a principle constituent of molding sand?

a) Silica

b) Aluminum

c) Iron oxide

d) Copper

Answer: d

Explanation: Copper is not a principle constituent of molding sand. Moulding sand is generally composed of silica, aluminum, and iron oxide.

2. When sand is in its natural moist state it is known as?

a) Green sand

b) Facing sand

c) Loam sand

d) Dry sand

Answer: a

Explanation: Green sand is a mixture of silica sand with 18-30% clay, having a water content in the range 6-8%. This name got its name “green” in the sense of “not ready” or “not processed” meaning.

3. Which of the following sand contains clay up to 50% and dries hard?

a) Green sand

b) Facing sand

c) Loam sand

d) Dry sand

Answer: c

Explanation: Loam sand contains clay up to 50% and dries hard. It covers less part of mould. This sand is used for loam sand moulds for making very heavy castings usually with the help of sweeps and skeleton patterns.

4. Which of the following sand is black in color?

a) Green sand

b) Facing sand

c) Loam sand

d) Backing sand

Answer: d

Explanation: Backing sand is black in color due to the presence of coal dust or due to burning. It contains mainly of old, used moulding sand which is black in colour due to the presence of coal dust etc on contact with any hot metal.

5. Which of the following sand is placed next to the surface and comes in contact with the molten metal?

a) Green sand

b) Facing sand

c) Loam sand

d) Backing sand

Answer: b

Explanation: Facing sand is placed next to the surface and meets the molten metal. Facing sand is the sand which covers the pattern all around it. The remaining box is filled with ordinary floor sand.

6. Green strength of sand does not depend upon?

a) Grain size

b) Moisture content

c) Shape and distribution of sand

d) Refractoriness of the sand

Answer: d

Explanation: The strength of the sand in green or moist state is termed as green strength. The green sand particles have the ability to cling to each other to impart sufficient strength to the mold.

7. The strength of the sand which is required to hold the shape of the mould cavity when the metal in the mould is still in liquid form is known as?

a) Hot strength

b) Green strength

c) High strength

d) Refractoriness of the sand

Answer: a

Explanation: When the moisture in sand being eliminated, the sand would reach at a high temperature when the metal in the mold is still in liquid state. The strength of the sand that is required to hold the shape of the cavity is called hot strength.

8. Which of the following will have better plasticity?

a) Coarse sand

b) Fine grained sand

c) Semi grained sand

d) Plasticity does not depend on sand grain size

Answer: b

Explanation: Plasticity is the ability of sand particles to undergo unrecoverable deformation at constant volume without cracking and crumbling. Fine grained sand particles will have better plasticity.

9. The passage of gaseous material, water and steam vapor through the molding sand is known as?

a) Plasticity

b) Flowability

c) Permeability

d) Refractoriness

Answer: c

Explanation: The passage of gaseous material, water and steam vapor through the molding sand is known as permeability. Sand which are coarse or have rounded grains exhibit more permeability. In the absence of adequate permeability, defects like surface blows, gas holes, mold blast etc. may be experienced.

10. Which of the following sand is coated with phenol or urea formaldehyde resins?

a) Shell sand

b) Green sand

c) Dry sand

d) Facing sand

Answer: a

Explanation: Shell sand is coated with phenol or urea formaldehyde resins.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Gating design”.

1. In which type of gating system aspiration effect takes place?

a) Vertical

b) Horizontal

c) Diagonal

d) Bottom

Answer: a

Explanation: When the molten metal is flowing through gating system and if somewhere along the gating system pressure fall below the atmosphere pressure, due to high velocity of molten metal then air from outside start flowing into the gating system due to pressure difference between atmospheric air and flow pressure, this effect is called as aspiration effect. Aspiration effect takes place in a vertical gating system. Aspiration effect leads to the formation of blow holes in the casting.

2. In the gate area for non-pressurized casting gating ratio a:b:c? .

a) 1:2:2

b) 2:2:1

c) 1:4:4

d) 1:4:2

Answer: c

Explanation: The gating ratio may be of the order of 3:2:1 for pressurized gating system and for unpressurized gating system is will be in 1:3:2. The further differences between pressurized and non-pressurized gating system are tabulated below:

S.No. Pressurized gating systems Unpressurized gating systems

1 Gating ratio may be of the order of 3:2:1 Gating ratio may be of the order of 1:3:2

2 Air aspiration effect is minimum Air aspiration effect is more

3 Volume flow of liquid from every ingate is almost equal Volume flow of liquid form every ingate is different

4 They are smaller in volume for a given flow rate of metal. Therefore, the casting yield is higher. They are larger in volume because they involve large runners and gates as compared to pressurized system and thus the cast yield is reduced.

5 Velocity is high, severe turbulence may occur at corners. Velocity is low and turbulence is reduced.

3. Which of the following is not a type of riser?

a) Top riser

b) Open riser

c) Internal riser

d) Bottom riser

Answer: d

Explanation: In casting process there are mainly two types of raisers are used: 1. Open riser , 2. Blind riser . Blind risers are good design features and maintain heat longer than open risers too.

4. Caine curve is a graph between?

a) Volume ratio and solidification ratio

b) Volume ratio to freezing ratio

c) Volume ratio to heating ratio

d) Freezing ratio to time ratio

Answer: b

Explanation: Caine curve is a graph between volume ratios to freezing ratio. Caine curve is used to determine exact volume for perfect freezing.

5. To prevent heavier and lighter impurities which of the following system is used?

a) Skim bob

b) Pouring basin

c) Strainer

d) Splash core

Answer: a

Explanation: Skim bob is a hollow above the runner that acts to skim off floating dross, sand and debris so it does not enter the casting.

6. To reduce the eroding force of the liquid metal which of the following system is used?

a) Skim bob

b) Pouring basin

c) Strainer

d) Riser

Answer: b

Explanation: The pouring basin or pouring cup is used to make the pouring operation easy and effective without losing the molten metal. Without a pouring basin with the right dimensions it would be hard to pour the metal from a ladle.

7. If velocity of metal flow at gate is 4m/sec, volume of mould is .1 cubic meters and the cross-sectional area of gate is 0.002 cubic meters then the time required to fill up the mould in seconds is?

a) 10

b) 12

c) 12.5

d) 15.5

Answer: c

Explanation: t = [v/ ], where v is volume, V is the velocity, a is the area and t is the time taken to fill the mould.

8. If the volume to surface area ratio is 2 for riser and for casting it is 4, then the freezing ratio is?

a) 2

b) 4

c) 8

d) .5

Answer: d

Explanation: The freezing ratio  of the mould is defined as the ratio of cooling characteristics of casting to the riser:

x = \(\displaystyle\frac{

 

_{casting}}{

 

_{riser}}\)

Freezing ratio, as per the given values in the question, x = \(\displaystyle\frac{

 

_{casting}}{

 

_{riser}} = \frac{2}{4}\) = 0.5.

9. Time required to fill the mould by vertical gating system is?

a) Less to bottom gating system

b) More to bottom gating system

c) Equal to bottom gating system

d) Sometimes more and sometimes less to bottom gating system

Answer: a

Explanation: Time required to fill the mould by vertical gating system is less than bottom gating system.

10. A mould has a down sprue length of 0.2 meters. The velocity of metal in meter/second at gate will be?

a) 1.78

b) 1.98

c) 2.3

d) 2.5

Answer: b

Explanation: Velocity = \(\sqrt{}\), where h is the length of down sprue, and g is the value of earth gravity which can be taken as 9.81.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Various Casting Process”.

1. Injection moulding is not a type of?

a) Die casting

b) Centrifugal casting

c) Squeeze casting

d) Investment casting

Answer: a

Explanation: In casting processes, there are two type of mould processes: 1. expendable mould processes, 2. permanent mould processes. Casting types such as, low-pressure PM casting, vacuum PM casting, die casting, squeeze casting, centrifugal casting, semi-centrifugal casting, injection moulding and compression moulding comes under permanent mould processes. Likewise, sand casting, shell casting, plaster casting, ceramic casting and investment casting are the types of expendable mould processes.

2. Which of the following statement is not correct about die casting?

a) It has close dimensional accuracy

b) Die has good life

c) It is very economical for large scale production

d) No need for removing the entrapped gases

Answer: d

Explanation: Gas entrapment is a very serious defect in all casting processes, and die casting too can go without them.

3. Which type of casting is preferred for making hollow pipes and tubes which are axisymmetric with concentric holes?

a) Centrifuging

b) True centrifugal casting

c) Semi-centrifugal casting

d) None of the mentioned

Answer: b

Explanation: Centrifugal casting is used to make hollow pipes. In this process, molten metal is poured in a mould which is rotating. The molten metal experiences centrifugal force and it is forced radially outward. The axis of rotation could be vertical, horizontal, or even inclined.

4. Which of the following casting is a combination of casting and forging?

a) Die casting

b) Centrifugal casting

c) Squeeze casting

d) Investment casting

Answer: c

Explanation: Squeeze casting is a combination of casting and forging. It is a process in which an alloy melt solidifies under the application of external pressure, in order to prevent the formation of shrinkage porosity.

5. In plaster mould casting the mould is made from?

a) CaSO 4

b) CaSO 3

c) CaSO 2

d) Ca(SO 4 ) 2

Answer: a

Explanation: The mould is made from plaster of Paris whose chemical formula is CaSO 4 Where Ca is calcium, S is sulphur and O represents oxygen.

6. In which casting process the sand is mixed with a thermosetting resin to form a mould?

a) Die casting

b) Centrifugal casting

c) Squeeze casting

d) Shell moulding

Answer: d

Explanation: The first step in the shell mold casting process is to manufacture the shell mold. The sand we use for the shell molding process is of a much smaller grain size than the typical greensand mold. This fine-grained sand is mixed with a thermosetting resin binder.

7. Which one of the following is a resin used in shell moulding technique?

a) Diphenyl aldehyde

b) Phenol formaldehyde

c) Methyl formaldehyde

d) Dimethyl formaldehyde

Answer: b

Explanation: Phenol formaldehyde and phenol formaldehyde are the two synthetic thermosetting resins used in shell moulding process.

8. Which casting is used to make hollow casting with thin walls?

a) Die casting

b) Centrifugal casting

c) Slush casting

d) Shell moulding

Answer: c

Explanation: Slush casting creates hollow castings with thin walls. This process gives thin-walled profiles with a superior surface finish.

9. In investment casting process which of the following is used for pattern making?

a) Ceramics

b) Molten wax

c) Silica

d) Plaster of paris

Answer: b

Explanation: Investment casting refers to the material being surrounded by a refractory material which is expendable, usually a ceramic. The wax carving is “invested” in the refractory material so to speak. Lox wax refers to a wax shape being made then surrounded with the refractory material to create a mold. The molten metal is then poured in the mold which melts the wax. As the wax runs out of the mold then the molten metal assumes the shape left by the impression of the wax object.

10. Which of the following is not an example of a precision casting process?

a) Plastic mould casting

b) Ceramic mould casting

c) Slush casting

d) Investment casting

Answer: d

Explanation: Precision casting is a lox wax casting  process. The lox was method of precision casting is suitable for producing casting with complex shapes and high dimensional accuracy.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Casting Defects”.

1. Which of the following defect is not a gas defect?

a) Blow holes

b) Air inclusions

c) Run out

d) Pin hole porosity

Answer: c

Explanation: Blow holes, air inclusions and pin hole porosity are known as “gas defects” in casting. Blow holes and open blows are spherical, flattened or elongated cavities present inside the casting or on the surface of the casting. These are caused b moisture left in the mold and core. Air inclusions are due to absorption of gases by the molten metal in the furnace, they cannot escape and weaken the mold during casting. These are due to high pouring temperatures. Pinhole defects are a form of gas porosity. They are usually small, elongated holes at or immediately below the casting surface with the long axis of the pinhole perpendicular to the casting surface.

2. Which gas defect is caused by hydrogen in molten metal?

a) Blow holes

b) Air inclusions

c) Open blows

d) Pin hole porosity

Answer: d

Explanation: As hydrogen is such a small atom, it can diffuse rapidly once it is absorbed, creating pinholes. Hydrogen being absorbed by the molten metal inside the furnace and inside the cavity. This is the main reason for the evolution of pinhole porosity.

3. Cuts, washes, swell, drop etc. are the examples of which of the following casting defects?

a) Gas defect

b) Pouring material defect

c) Moulding material defect

d) Metallurgical defect

Answer: c

Explanation: Moulding material defects are caused by the characteristics of molding materials. Cuts, washes, swell, drop etc. are some known examples of this type. These are caused by poor strength of moulding sand or molten metal flowing at high velocity.

4. When the molten metal leaks out of mould which defect occurs?

a) Run out

b) Misrun

c) Fusion

d) Drop

Answer: a

Explanation: A run out occurs when molten metal leaks out of the mould during pouring. This is caused by defecting moulding boxes, faulty clamping and weighing and by casting too near the edge of the box. This defect is avoided by modifying the moulding system, providing proper line and providing proper gating system.

5. Which of the following defects is not an example of type “pouring material defects”?

a) Misrun

b) Cold shut

c) Slag inclusion

d) Hot tear

Answer: d

Explanation: Misruns, cold shut, shrinkage cavity, micro porosity, mismatch and metal penetration are the pouring metal defects. Among these, misrun is caused when the metal is unable to fill the mould cavity completely. Cold shut is caused when two metal streams while meeting in the mould cavity do not fuse together properly.

6. The lower fluidity of molten material causes _________

a) Misrun

b) Cold shut

c) Misrun & Cold shut

d) Fusion

Answer: c

Explanation: Fluidity is a very important consideration in metal casting. Cold shuts and misruns can be caused by a lack of fluidity in the metal.

7. Defects caused by the chilling of the casting are known as?

a) Hot spots

b) Hot tears

c) Shrinkage cavity

d) Swell

Answer: a

Explanation: Hot spots are the thick sections, those cool slower than other sections causing abnormal shrinkage. Defects such as voids cracks and porosity are created at these hot spots.

8. During melting process flux is added to react with impurities to form?

a) Cavity

b) Slag

c) Cold shut

d) Blow holes

Answer: b

Explanation: Slag is said to be refuse produced as a result of melting nonferrous material which have a high melting point, it is thus formed when added flux to interact with impurities. If slag is not completely removed it may cause slag inclusions.

9. Which defect is caused due to the conversion of moisture to steam because of the heat of molten metal?

a) Blow holes

b) Open blows

c) Air inclusions

d) Cold shut

Answer: a

Explanation: Blow holes are entrapped gases, which are formed as a result of gases from mould, molten metal and stream sand. Further these are caused due to the conversion of moisture to steam because of the heat of molten metal.

10. Defect which occurs due to the solidification of casting is known as?

a) Swell

b) Misrun

c) Metal penetration

d) Shrinkage cavity

Answer: d

Explanation: Shrinkage cavity is a void on the surface of the casting caused mainly due to uncontrolled and haphazard solidification of the metal. These can be of two types,

i. External shrinkage defects and

ii. Closed shrinkage defects.

The main causes are inadequate and improper gating and risering system, too much high pouring temperature, and improper chilling.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Metal Casting Defects”.

1. The major defects of casting are __________

a) gas defects

b) shrinkage cavities

c) molding material defects

d) all of the mentioned

Answer: d

Explanation: Following are the major defects, which are likely to occur in casting:

i) gas defects

ii) shrinkage cavities

iii) molding material defects

iv) pouring metal defects

v) mold shift.

2. The defects caused by trapping a gas in molten metal or by mold gases while pouring the melt is known as?

a) Gas defects

b) Shrinkage cavities

c) Molding material defects

d) Pouring defects

Answer: a

Explanation: Shrinkage cavities are caused by liquid shrinkage occurring during the solidification of the casting while gas defects are a condition existing in a casting caused by the trapping of gas in the molten metal or by mold gases evolved during the pouring of the casting.

3. The causes of gas defects are ___________

a) metal contains gas

b) mold is too hot

c) poor mold burnout

d) all of the mentioned

Answer: d

Explanation: The lower gas-passing tendency of the mold, which may be due to lower venting, lower permeability of the mold or improper design of the casting. The lower permeability is caused by finer grain size of the sand, high percentage of clay in mold mixture, and excessive moisture present in the mold.

Metal contains gas

Mold is too hot

Poor mold burnout.

4. The defects caused by liquid shrinkage during the solidification of the casting?

a) gas defects

b) shrinkage cavities

c) molding material defects

d) hot tears

Answer: b

Explanation: Shrinkage cavities are caused by liquid shrinkage occurring during the solidification of the casting while gas defects are a condition existing in a casting caused by the trapping of gas in the molten metal or by mold gases evolved during the pouring of the casting.

5. In casting, which of the following are not material defects?

a) cut and washes

b) metal penetration

c) fusion

d) hot tears

Answer: d

Explanation: The defects in this category are cuts and washes, metal penetration, fusion, and swell.

6. The defect caused when the melt is unable to fill the mold cavity completely and thus leaves cavities is termed as?

a) cold shut

b) misrun

c) hot tear

d) porosity

Answer: b

Explanation: A mis-run is caused when the metal is unable to fill the mold cavity completely and thus leaves unfilled cavities and a cold shut is caused when two streams while meeting in the mold cavity, do not fuse together properly thus forming a discontinuity in the casting.

7. The defect caused when two streams do not fuse together , thus forming discontinuity in casting is termed as?

a) cold shut

b) misrun

c) hot tear

d) porosity

Answer: a

Explanation: A mis-run is caused when the metal is unable to fill the mold cavity completely and thus leaves unfilled cavities and a cold shut is caused when two streams while meeting in the mold cavity, do not fuse together properly thus forming a discontinuity in the casting.

8. A casting defect which occurs near the ingates as rough lumps on the surface of a casting is?

a) Shift

b) Sand wash

c) Swell

d) Hot tear

Answer: b

Explanation: Swell is caused under the influence of metallostatic forces, the mold wall may move back causing a swell in the dimension of the casting whereas Sand wash is a casting defect which occurs near the ingates as rough lumps on the surface of a casting.

9. A casting defect which occurs due to improper venting of sand is known as?

a) Cold shuts

b) Blow holes

c) Shift

d) Hot tear

Answer: c

Explanation: The mold shift defect occurs when cope and drag or molding boxes have not been properly aligned and a cold shut is caused when two streams while meeting in the mold cavity.

10. Scabs are casting defects which?

a) result in a mismatch of the top and bottom parts of a casting

b) result near the ingates as rough lumps on the surface of a casting

c) occur as rough and irregular projections on the surface of the casting

d) occur as smooth and regular projections on the surface of the casting

Answer: c

Explanation: A casting defect which occurs near the ingates as rough lumps on the surface of a casting is sand wash and scabs are casting defects which occur as rough and irregular projections on the surface of the casting.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Metal Casting Processes and Equipment”.

1. Which of the following are typically made of sand, plaster, ceramics and similar materials and generally are mixed with various binders?

a) Permanent molds

b) Expendable molds

c) Composite molds

d) Ceramic molds

Answer: b

Explanation: Expendable molds, which typically are made of sand, plaster, ceramics, and similar materials and generally are mixed with various binders  for improved properties whereas permanent molds, which are made of metals that maintain their strength at high temperatures.

2. Which of the following are made of metals that maintain their strength at high temperatures?

a) Permanent molds

b) Expendable molds

c) Composite molds

d) Ceramic molds

Answer: a

Explanation: Expendable molds, which typically are made of sand, plaster, ceramics, and similar materials and generally are mixed with various binders  for improved properties whereas permanent molds, which are made of metals that maintain their strength at high temperatures.

3. Which of the following expandable molds are less heat conductors than metallic molds?

a) metallic

b) nonmetallic

c) composite

d) ceramic

Answer: b

Explanation: Metal molds are better heat conductors than expendable non-metallic molds, hence, the solidifying casting is subjected to a higher rate of cooling, which in turn affects the microstructure and grain size Within the casting.

4. Which of the following are made of two or more different materials ?

a) Permanent molds

b) Expendable molds

c) Composite molds

d) Ceramic molds

Answer: c

Explanation: Composite molds, which are made of two or more different materials  combining the advantages of each material.

5. The directional solidification in casting can be improved by using __________

a) chaplets and riser

b) chills and padding

c) chaplets and padding

d) chills and riser

Answer: d

Explanation: Directional solidification is solidification that occurs from farthest end of the casting and works its way towards the sprue. Chills and riser are used in improving directional solidification.

6. In permanent mold casting method __________

a) molten metal is poured in a metallic mold, retained in the mold long enough for the outer skin to solidify and finally mold is turned over to remove molten metal still in molten condition

b) molten metal is poured and allowed to solidify while the mold is revolving

c) Molten metal is forced into mold under high pressure

d) none of the mentioned

Answer: d

Explanation: Permanent mold castings are used repeatedly and are designed in such a way that the casting can be removed easily and the mold used for the next casting. Metal molds are better heat conductors than expendable non-metallic molds hence, the solidifying casting is subjected to a higher rate of cooling, which in turn affects the microstructure and grain size Within the casting.

7. In which of the following casting method, the molten metal is poured and allowed to solidify while the mold is revolving?

a) die casting method

b) slush casting method

c) centrifugal casting method

d) investment casting method

Answer: c

Explanation: A casting process in which the molten metal is poured and allowed to solidify while the mold is revolving, is called centrifugal process. The casting produced under this centrifugal force is called centrifugal casting. This process is especially designed for a casting of symmetrical shape.

8. In a hot chamber die casting machine __________

a) melting pot is separate from the machine

b) melting pot is an integral part of the machine

c) melting pot may have any location

d) there is no melting pot in die casting machine

Answer: b

Explanation: In a hot chamber die casting machine, the melting pot is an integral part of the machine. The molten metal is forced in the die cavity at a pressure from 7 to 14 MPa.

9. Cast iron and steel pipes are produced by __________

a) slush casting

b) investment casting

c) true centrifugal casting

d) die casting

Answer: c

Explanation: The method of Cast Iron pipe production used universally today is to form pipes by spinning or centrifugal action. Compared with vertical casting in sand molds, the spun process results in faster production, longer pipes with vastly improved metal qualities, a smoother inner surface and reduced thickness and consequent light weight.

10. Which of the following statement is wrong?

a) The hot chamber die casting machine is used for casting zinc, tin, lead and other low melting alloys

b) The cold chamber die casting machine is used for casting aluminum, magnesium, copper base alloys and other high melting alloys

c) The castings produced by centrifugal casting method have open and coarse grained structure

d) The castings produced by centrifugal casting method have fine grained structure

Answer: c

Explanation: The casting produced by centrifugal casting process have dense and fine grained structure.

11. The melting temperature of non-ferrous alloys, to be casted in a cold chamber die casting machine are of?

a) low melting temperature

b) high melting temperature

c) two eutectic points

d) three eutectic points

Answer: b

Explanation: In a cold chamber die casting machine, the melting pot is usually separate from the machine and the molten metal is not transferred to injection mechanism by ladle. The pressure on the casting metal may vary from 21 to 210 MPa and in some cases may reach 700 MPa.

12. The centrifugal casting method, is used for casting articles of __________

a) symmetrical shape about horizontal axis

b) symmetrical shape about vertical axis

c) irregular shape

d) sphere shape

Answer: a

Explanation: In centrifugal casting, because gravity force is applied in same in horizontal direction axis, so the material is distributed equally in all directions.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Expendable Mold, Permanent-Pattern Processes”.

1. Applications of sand casting include __________

a) machine bases

b) large turbine impellers

c) propellers

d) automobile gears

Answer: d

Explanation: Typical applications of sand casting include machine bases, large turbine impellers, propellers, plumbing fixtures, and a wide variety of other products and components.

2. Sand casting consists of __________

a) placing a pattern in sand to make an imprint

b) incorporating a gating system

c) removing the pattern and filling the mold cavity with molten metal

d) all of the mentioned

Answer: d

Explanation: Basically, sand casting consists of

a) placing a pattern  in sand to make an imprint,

b) incorporating a gating system,

c) removing the pattern and filling the mold cavity with molten metal,

d) allowing the metal to cool until it solidifies,

e) breaking away the sand mold, and

f) removing the casting.

3. Which of the following are used to mold the sand mixture into shape of the casting and may be made of wood, plastic, metal?

a) Vents

b) Patterns

c) Cores

d) Chills

Answer: b

Explanation: Patterns are used to mold the sand mixture into the shape of the casting and may be made of wood, plastic, or metal. The selection of a pattern material depends on the size and shape of the casting, the dimensional accuracy and the quantity of castings required, and the molding process.

4. Which of the following fill the flask uniformly with sand under a high-pressure stream?

a) Sandslingers

b) Patterns

c) Cores

d) Chills

Answer: a

Explanation: A sand slinger is an automatic machine equipped with a unit that throws sand rapidly and with great force into the mould box. Sand slingers fill the flask uniformly with sand under a high-pressure stream, they are used to fill large flasks and are operated typically by machine.

5. In which of the following technique, sand is compacted by a controlled explosion or instantaneous release of compressed gases?

a) vacuum molding

b) impact molding

c) blow molding

d) rotational molding

Answer: b

Explanation: In impact molding, the sand is compacted by a controlled explosion or instantaneous release of compressed gases whine in vacuum molding the pattern is covered tightly with a thin sheet of plastic.

6. In which of the following technique, the pattern is covered tightly with a thin sheet of plastic?

a) vacuum molding

b) impact molding

c) blow molding

d) rotational molding

Answer: a

Explanation: In vacuum molding , the pattern is covered tightly with a thin sheet of plastic while in impact molding, the sand is compacted by a controlled explosion or instantaneous release of compressed gases.

7. Shell-molding applications include ____________

a) small mechanical parts requiring high precision

b) such as gear housings

c) cylinder heads

d) all of the mentioned

Answer: d

Explanation: Shell-molding applications include small mechanical parts requiring high precision, such as gear housings, cylinder heads, and connecting rods. The process also is used widely in producing high-precision molding cores.

8. Along with plaster of paris, with the addition of tale, which of the following is added in the plaster-molding process?

a) copper

b) iron

c) silica

d) calcium

Answer: c

Explanation: In the plaster-molding process, the mold is made of plaster of paris  with the addition of tale and silica flour to improve strength and to control the time required for the plaster to set.

9. Typical parts such as impellers, cutters for machining operations are made by?

a) plaster-molding process

b) ceramic-mold casting process

c) shell-molding

d) metallic-mold casting process

Answer: b

Explanation: Typical parts made are impellers, cutters for machining operations, dies for metalworking, and molds for making plastic and rubber Components. Parts weighing as much as 700 kg have been cast by this process.

10. The surface finish in a plaster-molding process is?

a) rough

b) good

c) slippery

d) bad

Answer: b

Explanation: In the plaster-molding process, castings have a good surface finish with fine details. Because plaster molds have lower thermal conductivity than other mold materials, the castings cool slowly, and thus a more uniform grain structure is obtained with less warpage.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Expendable Mold, Expendable-Pattern Processes”.

1. Which of the following casting process uses a polystyrene pattern?

a) investment casting

b) ceramic-shell casting

c) evaporative-pattern casting

d) slush casting

Answer: c

Explanation: The evaporative-pattern casting process uses a polystyrene pattern, which evaporates upon contact with molten metal to form a cavity for the casting. This process is also known as lost-foam casting and falls under the trade name full-mold process.

2. Which of the following casting process is used to make typical parts such as gears, cams, valves, etc?

a) investment casting

b) ceramic-shell casting

c) evaporative-pattern casting

d) slush casting

Answer: a

Explanation: The investment-casting process, also called the lost-wax process, was first used during the period from 4000 to 3000 B.C. Typical parts made are components for office equipment, as well as mechanical components such as gears, cams, valves, and ratchets.

3. In which of the following casting, two halves of a mold are made from materials with high resistance?

a) investment casting

b) permanent-mold casting

c) evaporative-pattern casting

d) slush casting

Answer: b

Explanation: In permanent-mold casting , two halves of a mold are made from materials with high resistance to erosion and thermal fatigue, such as cast iron, steel, bronze, graphite, or refractory metal alloys.

4. To increase the life of permanent molds, the surfaces of the mold cavity usually are coated with a ____________

a) refractory slurry

b) silver

c) aluminum

d) zinc

Answer: a

Explanation: In order to increase the life of permanent molds, the surfaces of the mold cavity usually are coated with a refractory slurry  or sprayed with graphite every few castings. These coatings also serve as parting agents and as thermal barriers, thus controlling the rate of cooling of the casting.

5. Which of the following casting technique is an alternative to investment, shell-mold, and green-sand casting?

a) Vacuum Casting

b) Permanent-mold casting

c) Evaporative-pattern casting

d) Expandable-mold casting

Answer: a

Explanation: Vacuum casting is an alternative to investment, shell-mold, and green-sand casting and is suitable particularly for thin-walled  complex shapes with uniform properties.

6. Hollow castings with thin walls can be made by permanent-mold casting using ___________

a) vacuum casting

b) slush casting

c) evaporative-pattern casting

d) investment casting

Answer: b

Explanation: Hollow castings with thin walls can be made by permanent-mold casting using this principle: a process called slush casting. This process is suitable for small production runs and generally is used for making ornamental and decorative objects  and toys from low-melting-point metals such as zinc, tin, and lead alloys.

7. In which of the following casting technique, the molten metal is forced upward by gas pressure into a graphite or metal mold?

a) vacuum casting

b) slush casting

c) pressure casting

d) investment casting

Answer: c

Explanation: In pressure casting , the molten metal is forced upward by gas pressure into a graphite or metal mold.

8. Which of the following are made of two or more different materials?

a) Composite molds

b) Centrifuging

c) Die casting

d) Investment casting

Answer: a

Explanation: Composite molds are made of two or more different materials and are used in shell molding and other casting processes. They generally are employed in casting complex shapes, such as impellers for turbines.

9. In which of the following casting technique, the metal is heated to just above its solidus temperature and poured into a vessel to cool it down to the semisolid state?

a) vacuum casting

b) rheocasting

c) pressure casting

d) investment casting

Answer: b

Explanation: In rheocasting, the metal is heated to just above its solidus temperature and poured into a vessel to cool it down to the semisolid state. The slurry is then mixed and delivered to the mold or die.

10. The advantages of semisolid metal forming over die casting are _____________

a) the structures developed are homogeneous, with uniform properties

b) casting as well as wrought alloys can be used

c) the lower superheat results in shorter cycle times

d) all of the mentioned

Answer: d

Explanation: The advantages of semisolid metal forming over die casting are

a) the structures developed are homogeneous, with uniform properties, lower porosity, and high strength

b) both thin and thick parts can be made

c) casting as well as wrought alloys can be used

d) parts subsequently can be heat treated,

e) the lower superheat results in shorter cycle times.

However, material and overall costs are higher than those for die casting.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Casting Techniques For Single Crystal Components”.

1. In which of the following casting process, the metal being poured into the mold begins to solidify at ceramic walls?

a) conventional casting

b) directional solidification

c) single crystal

d) induction melting

Answer: a

Explanation: The conventional-casting process uses a ceramic mold. The molten metal is poured into the mold and begins to solidify at the ceramic walls. The grain structure developed is poly crystalline.

2. In which of the following casting process, preheating of ceramic mold is done by radiation?

a) conventional casting

b) directional solidification

c) single crystal

d) induction melting

Answer: b

Explanation: The directional-solidification process was first developed in 1960. The ceramic mold is preheated by radiant heating, and the mold is supported by a water-cooled chill plate.

3. In which of the casting process, the mold has either corkscrew or helical shape construction?

a) conventional casting

b) directional solidification

c) single crystal

d) induction melting

Answer: c

Explanation: In crystal growing, developed in 1967, the mold has a constriction in the shape of a corkscrew or helix. The cross section is so small that it allows only one crystal to fit through.

4. Which of the following casting technique has a greater impact in semiconductor industry?

a) conventional casting

b) directional solidification

c) single crystal

d) induction melting

Answer: c

Explanation: Single-crystal growing is a major activity in the semiconductor industry in the manufacture of the silicon wafers in microelectronic devices.

5. Which of the following parameter is used to determine the nature of cast components by sealing the opening in casting?

a) Surface defects

b) Pressure tightness

c) Ductility

d) Brittleness

Answer: b

Explanation: Pressure tightness of cast components  usually is determined by sealing the openings in the casting and pressurizing it with Water, oil, or air.

6. Which of the following test allows us to remove specimens form various casting sections?

a) surface defects

b) pressure tightness

c) destructive

d) non-destructive

Answer: b

Explanation: In destructive testing, specimens are removed from various sections of a casting and tested for strength, ductility, and other mechanical properties and to determine the presence, location, and distribution of porosity and any other defects.

7. In which of the following casting method, alloy is melted by induction in a ceramic crucible?

a) conventional casting

b) melt spinning

c) pressure die casting

d) vacuum arc melting

Answer: b

Explanation: In a common method called melt spinning, the alloy is melted by induction in a ceramic crucible. It is then propelled under high gas pressure against a rotating copper disk , which chills the alloy rapidly.

8. Which of the following casting technique, a seed crystal is dipped into the molten metal and then pulled out slowly?

a) crystal pulling method

b) melt spinning

c) single crystal

d) Sankaranarayanan Ramasamy method

Answer: a

Explanation: In the crystal-pulling method, a seed crystal is dipped into the molten metal and then pulled out slowly  while being rotated.

9. The zone at which a rod of polycrystalline silicon rests on a single crystal and an induction coil heats these two pieces is called as?

a) crystal pulling method

b) melt spinning

c) floating zone

d) vacuum arc melting

Answer: c

Explanation: The second technique for crystal growing is the floating-zone method. Starting with a rod of polycrystalline silicon resting on a single crystal, an induction coil heats these two pieces while the coil moves slowly upward. The single crystal grows upward while maintaining its orientation.

10. In which of the following method, dopants are added?

a) crystal pulling method

b) melt spinning

c) floating zone

d) vacuum arc melting

Answer: a

Explanation: In the crystal-pulling method, dopants may be added to the liquid metal to impart special electrical properties. Single crystals of silicon, germanium, and various other elements are grown with this process.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Forming”.

1. Depending upon the temperature the forming process can be classified as?

a) Hot working

b) Cold working

c) Warm working

d) All of the mentioned

Answer: d

Explanation: Depending upon the temperature the forming process can be classified as hot working, cold working, and warm working.

2. If T m is the melting temperature, then in hot working the value for that material is?

a) 0.5 T m

b) 0.6 T m

c) 0.4 T m

d) 0.7 T m

Answer: b

Explanation: If T m is the melting temperature then in hot working the value of T m is .6 T m . Hot working is done above recrystallization temperature.

3. In which of the following process no strain hardening is produced?

a) Hot working

b) Cold working

c) Warm working

d) Cannot say

Answer: a

Explanation: In hot working , no strain hardening is produced, this is because, when hot working is done, there is simultaneous recrystallization and grain growth due to elevated temperature. So, the material regains its ductility and there is no residual stress in the material.

4. During hot working, the grain growth can take place in which part of the material?

a) Exterior

b) Interior

c) Along the edges

d) Side faces

Answer: b

Explanation: During hot working, the grain growth can take place in the interior part of the material because the interior part cools slowly the remaining parts.

5. Which of the following defect is eliminated by hot working process?

a) Cold shut

b) Misrun

c) Blow holes

d) Fusion

Answer: c

Explanation: Blow holes and porosities can be eliminated at high temperature, thus in hot working process.

6. The working temperature of cold working is below a certain temperature. That temperature is known as?

a) Critical temperature

b) Recrystallization temperature

c) Transition temperature

d) Curie temperature

Answer: b

Explanation: Recrystallization temperature is generally defined as temeprature at which complete recrystallization occurs within approximately one hour, in other sense, recrystallization temperature of a given metal is about one-half its melting point  as measured on an absolute temperature scale.

7. In which of the following process the ductility of material decreases?

a) Hot working

b) Cold working

c) Warm working

d) Cannot say

Answer: b

Explanation: Cold working is the work done below recrystallization temperature. As cold work is increased, yield strength and tensile strength increases, percentage of ductility decreases.

8. Which of the following statement is true about cold working?

a) Strain hardening is relieved

b) No oxidation occurs

c) Only limited amount of reduction can be done

d) Cost of machining is high

Answer: a

Explanation: A comparison of hot and cold working are tabulated below:

S.No. Hot Working Cold Working

1. Working above recrystallization temperature Working below recrystallization temperature

2. Formation of new crystals No crystal formation

3. Surface finish is not good Surface finish is good

4. No stress formation Internal stress developed

5. Improved mechanical property due to grain formation Leads to distortion of metal grains

6. Closed dimensional tolerances cannot be maintained Superior dimensions can be obtained

7. Improves some mechanical properties like, impact strength and elongation During process, strength and elongation decreases

9. In which of the following process plastic deformation takes place?

a) Cold working

b) Hot working

c) Both cold working and hot working

d) Cannot say

Answer: c

Explanation: Operations that induce shape changes on the workpiece by plastic deformation under forces applied by various tools and dies are termed as plastic deformation processes. Plastic deformation of metals below the recrystallization temperature is known as cold working and the plastic deformation carried above recrystallization temperature is termed as hot working.

10. In metal forming process the hardness of the material?

a) Decreases

b) Remains same

c) Initially increases and then decreases

d) Increases

Answer: d

Explanation: When metal is formed in cold stat, there is no recrystallization of grains and thus recovery of grains and thus recovery from grain distortion or fragmentation does not take place. As grain deformation proceeds, greater resistance to this action results in increased hardness and strength. The metal is said to be strain hardened.

11. The work involved with the internal shearing process due to non-uniform deformation is?

a) Ideal work

b) Frictional work

c) Redundant work

d) Slip work

Answer: c

Explanation: Redundant work is the energy expended on deformation the body which is not involved in a pure change in shape, in other sense, the redundant work is the work involved in internal shearing processes due to non-uniform deformation that does not contribute directly to change in shape of the body.

12. Which of the following method is used for analyzing metal forming processes?

a) Slab method

b) Upper bound method

c) Slip line method

d) All of the mentioned

Answer: d

Explanation: There are two kinds of mode of analyses i. analytical numerical methods, ii. empirical methods. The methods such as elementary theory , slip line field theory, finite element method , finite difference method  and upper & lower bound method are the types of analytical numerical methods. Similarity theory and visco-plastic method are of empirical methods.

13. Which of the following method is commonly used for analyzing metal forming processes?

a) Slab method

b) Upper bound method

c) Slip line method

d) Empirical method

Answer: a

Explanation: Out of all analysing methods, perhaps, slab method  is commonly used and is a simple analytical procedure based on principles of mechanism.

14. Warm working is done at a temperature?

a) Above re crystallization temperature

b) Below re crystallization temperature

c) Equal to re crystallization temperature

d) Below re crystallization temperature and above room temperature

Answer: d

Explanation: Warm working is done at a temperature below recrystallization temperature and above room temperature. In warm working some strain hardening or precipitation hardening may occur. Usual warm working temperature is of 0.3T m to 0.5 T m .

15. Which process got a better dimensional accuracy?

a) Hot working

b) Cold working

c) Warm working

d) Both Hot working and Cold working

Answer: a

Explanation: In cold working metal is shaped by the application of pressure at temperature below recrystallization temperature of the metal. In most cases it is done at room temperature. This is done to achieve close dimensions and accuracies and to improve mechanical properties. It is often done after hot working to obtain better dimensional control.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Introduction To Forging”.

1. Shaping of metal by squeezing them in between two or more dies in order to obtain desire shape is done by?

a) Forming

b) Forging

c) Welding

d) Grinding

Answer: b

Explanation: Forging is the term applied to a family of processes where deformation is induced by localized compressive forces. The forging material may be drawn out to increase its length and decrease its cross section upset to decrease the length and increase the cross section squeezed in closed impression dies to produce multidirectional flow.

2. Forging is carried out at which temperature?

a) Below recrystallization temperature

b) Above recrystallization temperature

c) Below or above recrystallization temperature

d) Above melting point

Answer: c

Explanation: Forging is the process of forming. It is of two types, hot and cold forging. Hot forging is done by heating a metal to about 60-65% of its melting temperature, thus above recrystallization temperature. Cold forging is generally used with soft metals, usually done at room temperature, thus below recrystallization temperature.

3. Which of the following is a type of forging?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: d

Explanation: There are basically three methods  to make a forged part, i. Impression die forging, ii. Closed die fording, iii. Open die forging. Some people call impression die forging too as closed die forging, and it is acceptable to call the same sometimes. Impression die forging pounds or presses metal between two dies  that contain a pre-cut profile of the desired part. In closed die forging the work piece is deformed between two die halves which carry the impression of the desired final shape. The open die forging is carried out between two flat dies or simple shapes.

4. In which of the following forging metal is kept in the lower die?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: a

Explanation: When shaping a solid piece of metal by closed die forging, the die is initially open. The work piece is placed in the lower die half, and the top die is then brought down to engage with the work piece The application of pressure between the slowly closing die halves causes the solid to flow plastically within the constrains of the die, being displaced to fill the outer sections of the die cavity.

5. In which of the forging process metal is kept in between a pair of dies and a gutter is provided in the lower die?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: b

Explanation: In closed die forging process metal is kept in between a pair of dies and a gutter is provided in the lower die. In impression die forging process metal is kept in between a pair of dies and no gutter is provided in the lower die.

6. In which of the forging process metal is kept in between a pair of dies and no gutter is provided in the lower die?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: c

Explanation: Sometimes, the closed die forging is also termed as impression die forging. In this impression are made in a pair of dies. These impressions are transferred to the work piece during deformation. A small gap between the dies called flash gutter is provided, so that, the excess metal can flow into the gutter and form a flash.

7. The extra metal which settles down in the gutter is known as?

a) Flash

b) Slag

c) Flux

d) Barrelling

Answer: a

Explanation: In impression die forging, the die surfaces contain a shape that is given to the work piece during compression, thus restricting the metal flow significantly. There is some extra deformed material outside the die impression which is called as flash. This will be trimmed off later.

8. In which of the following forging process no flash is formed?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: b

Explanation: In flashless forging, the work piece is fully restricted within the die and no flash is produced. The amount of initial work piece used must be controlled accurately so that it matches the volume of the die cavity.

9. In which of the following forging process poor material utilization occurs?

a) Open die

b) Closed die

c) Impression dies

d) Hold dies

Answer: a

Explanation: In the case of open die forging, lower material utilization, machining of the final shape is necessary, slow production rate, low lead times, commonly used for one-offs and high usage of skilled labour.

10. Cogging, which is also called as drawing out, is basically?

a) Open die forging operation

b) Closed die forging operation

c) Impression dies forging operation

d) Hold die forging operation

Answer: a

Explanation: Cogging is an open die forging process in which flat or slightly contoured die are employed to compress a work piece, reducing its thickness and increasing its length.

11. In rolling operation, the roll rotates with surface velocity?

a) exceeding the speed of incoming metal

b) lower than the speed of incoming metal

c) equal to speed of the incoming metal

d) Very higher than the speed of incoming metal

Answer: c

Explanation: The rolls rotate with a surface velocity exceeding the speed of the incoming metal, friction along the contact interface acts to propel the metal forward. The metal is squeezed and elongated and usually changed in cross section.

12. A round billet made of 70-30 brass is extruded at a temperature of 675°C. The billet diameter is 125 mm, and the diameter of the extrusion is 50 mm. Calculate the extrusion force required.

a) 4 MN

b) 5 MN

c) 5.6 MN

d) none of the mentioned

Answer: c

Explanation: The extrusion force is calculated using

Eq. F = A 0 k ln(A 0 /A f )

in which the extrusion constant, k, is obtained.

For 70-30 brass, k = 250 MPa at the given extrusion temperature. Thus,

F =  2 )/4 x  ln [ 2 )/ 2 )] = 4

= 5.6 MN.

13. In which type of extrusion, a billet is placed in a chamber?

a) forward

b) indirect

c) hydrostatic

d) impact

Answer: a

Explanation: In forward extrusion, a billet is placed in a chamber and forced through a die opening by a hydraulically driven ram. The die opening may be round, or it may have various shapes, depending on the desired profile.

14. In which type of extrusion, the die moves toward the unextruded billet?

a) forward

b) indirect

c) hydrostatic

d) impact

Answer: b

Explanation: In indirect extrusion, , the die moves toward the unextruded billet. Indirect extrusion has the advantage of having no billet-container friction, since there is no relative motion.

15. In which type of extrusion, the billet is smaller in diameter than the chamber?

a) forward

b) indirect

c) hydrostatic

d) impact

Answer: c

Explanation: In hydrostatic extrusion, the billet is smaller in diameter than the chamber , and the pressure is transmitted to the fluid by a ram.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Forging Operations-1”.

1. In which of the following forging operation no special die is used?

a) Drop forging

b) Smith forging

c) Coining

d) Press forging

Answer: b

Explanation: Smith forging is also called flat die and open die forging. It includes the broad field of forging work produced between flat faced dies and possibly supplemented by stock tooling. The final shape of the forging depends on the skill of the smith for size and shape. Smith forging produces work pieces of lesser accuracy as compared to impression or closed die forging. Tooling is simple, inexpensive and allows the production on large variety of shapes.

2. In which of the following forging operation repeated hammering and closed die is used?

a) Drop forging

b) Smith forging

c) Coining

d) Press forging

Answer: a

Explanation: Hammer forging is also called as drop forging where a hammer hits the work piece repeatedly to deform it. There are different types of hammers like gravity drop, counter blow and powder hammers.

3. In which of the following forging operation instead of repeated hammering gradual force is applied?

a) Drop forging

b) Smith forging

c) Coining

d) Press forging

Answer: d

Explanation: Press forging is variation of drop-hammer forging. Unlike drop-hammer forging, press forges work slowly by applying continuous pressure or force. The amount of time the dies are in contact with the workpiece is measured in seconds . The press forging operation can be done either cold or hot. The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece.

4. Coining and forming are two special kinds of which forging operation?

a) Upset

b) Press

c) Hubbing

d) Swaging

Answer: b

Explanation: Coining is a severe metal squeezing operation in which the flow of metal occurs at the top layers of the material and not throughout the values The operation is carried out in closed dies mainly for the purpose of producing fine details such as needed in minting coins, and metal or jewellery making. The blank is kept in the die cavity and pressure as high as five to six times the strength of material is applied. Depending upon the details required to be coined on the part, ore than one coining operation may be used.

5. Which of the following forging operation is used for parts having uniform cross section?

a) Upset

b) Press

c) Hubbing

d) Swaging

Answer: a

Explanation: In upset forging, a bar of uniform cross section usually round, is held between grooved dies, pressure is applied on the end in the direction of the axis of the bar by using a heading tool which spreads the end by metal displacement.

6. In which of the following technique shaping of a cross section of tubes or rods is done by means of repeated impacts or blows?

a) Upset

b) Press

c) Hubbing

d) Swaging

Answer: d

Explanation: Swaging is a mechanical deformation technique of reducing or shaping the cross section of rods or tubes by means of repeated impacts or blows.

7. Heading is a kind of which forging operation?

a) Piercing

b) Embossing

c) Upsetting

d) Coining

Answer: c

Explanation: A heading tool or ram is positioned perpendicular to the cross sectioned end face of a rod or bar gripped in a die. On application of pressure, the length of the rod is reduced, and the diameter is increased . This manufacturing process used extensively in the production of fasteners, to form bolt heads, screw heads etc.

8. In heading to avoid buckling the length to diameter ratio should be?

a) 1:3

b) 2:3

c) 3:1

d) 2:1

Answer: c

Explanation: Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding. In upset forging, the aspect ratio  should be 3:1.

9. Which operation is used in making raised figures on sheets with its corresponding relief on the other side?

a) Roll forging

b) Embossing

c) Coining

d) Heading

Answer: b

Explanation: Embossing is an operation in which sheet metal is drawn to shallow depths with male and female matching dies. The operation is carried out mostly for the purpose of stiffening flat panels. The operation is also sometimes used for making decoration items like number plates or name plates, jewellery, etc. Embossing operation with two dies, letters, numbers and designs on sheet-metal parts can be produced by the is operation.

10. Which of the following operation is used to make ball bearing?

a) Skew rolling

b) Roll forging

c) Press forging

d) Upsetting

Answer: a

Explanation: A special type, skew rolling is used to manufacture milling steel ball, bearing ball blanks.

This set of Manufacturing Science Problems focuses on “Forging Operations-2”.

1. In which forging process cross section of a bar is reduced or shaped by passing it through a pair of rolls with shaped grooves?

a) Skew rolling

b) Roll forging

c) Press forging

d) Upsetting

Answer: b

Explanation: Roll forging is a process where round or flat bar stock is reduced in thickness and increased in length. It is performed using two cylindrical or semi-cylindrical rolls each containing one or more shaped grooves.

2. In which of the following process a hardened punch is pressed into the surface of a block metal?

a) Upset

b) Press

c) Hubbing

d) Swaging

Answer: c

Explanation: Hubbing is a process consists of pressing a hardened punch with a tip geometry into the surface of a block of metal.

3. Which of the following statement is not correct about coining process?

a) It is a closed die forging process

b) It is used in minting of coin, jewellery etc

c) Lubrication is not used

d) All of the mentioned

Answer: d

Explanation: Coining is a forging process which is used for the minting of coins, jewellery etc.

4. In which of the following process radial movement of shaped died occur?

a) Upset

b) Press

c) Hubbing

d) Swaging

Answer: d

Explanation: The swaging dies perform high frequency radial movements with short strokes. The stroke frequencies are ranging from 1,500 to 10,000 per minute depending on the machine size, with total stroke lengths of 0.2 to 5 mm. The radial movements of the dies are for most applications simultaneous.

5. In which process surface is intended with a punch in order to produce a cavity or an impression?

a) Heading

b) Hubbing

c) Piercing

d) Swaging

Answer: c

Explanation: Piercing is a process of indenting the surface of a workpiece with a punch in order to produce a cavity or an impression. The piercing force depends on the x-sectional area and the tip geometry of punch, strength of material, and magnitude of friction at the sliding interfaces.

6. Which defect occurs in drop forging due to incorrectly aligned dies?

a) Miss match

b) Misrun

c) Swell

d) Cold shut

Answer: a

Explanation: Mismatch is caused by the misalignment of the die halves. Using mistake proofing for proper alignment for e.g. Providing half notch on upper and lower die so that at the time of alignment notch will match each other.

7. If scales are not removed from dies, then which of the following defects occur?

a) Miss match

b) Scale pits

c) Swell

d) Cold shut

Answer: b

Explanation: The forging defects, scale pits are due to improper cleaning of forged surface. This defect generally associates with forging in open environment. It is irregular deputations on the surface of forging.

8. Which of the following defects results due to improper forging?

a) Seams

b) Cracks

c) Laps

d) All of the Mentioned

Answer: d

Explanation: Seams, cracks and laps are the defect, which arises due to improper forging method.

9. To remove the scales after forging operation which of the following cleaning operation is done?

a) Pickling in acid

b) Shot peening

c) Pickling in acid & Shot peening

d) Smith forging

Answer: c

Explanation: Scales generated after forging operations are removed by using pickling in acid method and shot peeing method.

10. Edging and fullering operations are not used in which of the following operation?

a) Drop forging

b) Smith forging

c) Coining

d) Press forging

Answer: d

Explanation: Edging and fullering operations are not used in press forging operation.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Shearing Operations”.

1. Punching a number of holes in a sheet is known as?

a) Perforating

b) Parting

c) Notching

d) Lancing

Answer: a

Explanation: Punching a number of holes in a sheet is known as perforating. Removing the pieces from the edge in shearing operation is known as notching.

2. Shearing the sheet into two or more pieces is known as?

a) Perforating

b) Parting

c) Notching

d) Lancing

Answer: b

Explanation: Parting involves cutting a sheet metal strip by a punch with two cutting edges that match the opposite sides of the blank.

3. Removing the pieces from the edge in shearing operation is known as?

a) Perforating

b) Parting

c) Notching

d) Lancing

Answer: c

Explanation: Notching is a shearing process during which a metal scrap piece is removed from the outside edge of a metal workpiece. Notching is typically a manually operated, low-production process.

4. Leaving a tab without removing any material is known as?

a) Perforating

b) Parting

c) Notching

d) Lancing

Answer: d

Explanation: The process of creating a partial cut in the sheet, so that no material is removed. The material is left attached to be sent and form a shape, such as a tab, vent, or louver is termed as lancing.

5. Moving a small straight punch up and down rapidly into a die is done by a process known as?

a) Perforating

b) Parting

c) Nibbling

d) Lancing

Answer: c

Explanation: Moving a small straight punch up and down rapidly into a die is done by a process known as nibbling. Leaving a tab without removing any material is known as lancing.

6. As the thickness of sheet is increased the clearance needed will also?

a) Increase

b) Decrease

c) No effect

d) First decreases and then increase

Answer: a

Explanation: As the thickness of sheet is increased the clearance needed will also increase. Clearance needed is directly proportional to thickness of sheet.

7. Bevelling is particularly suitable for shearing of?

a) Thin blanks

b) Thick blanks

c) Very thin blanks

d) Medium thin blanks

Answer: b

Explanation: Beveling is particularly suitable for shearing of thick blanks.

8. Which of the following is a type of die?

a) Simple dies

b) Progressive dies

c) Compound die

d) All of the Mentioned

Answer: d

Explanation: All the above options are correct. In investment casting process molten wax is used for pattern making. It is a costly process but have a very good dimensional accuracy.

9. Which of the following die can perform multiple operations such as blanking, punching, notching etc.?

a) Simple dies

b) Progressive dies

c) Compound die

d) Impact dies

Answer: b

Explanation: Progressive die can perform multiple operations such as blanking, punching, notching etc. In investment casting process molten wax is used for pattern making. It is a costly process but have a very good dimensional accuracy.

10. As the clearance increases, the punch force required?

a) Decreases

b) Increases

c) Remains same

d) First increases and then decreases

Answer: a

Explanation: As the clearance increases, the punch force required decreases. As the thickness of sheet is increased the clearance needed will also increase. Clearance needed is directly proportional to thickness of sheet.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Extrusion”.

1. In which process the cross section of the metal is reduced by forcing it to flow through a die under high pressure?

a) Forging

b) Forming

c) Extrusion

d) Welding

Answer: c

Explanation: Extrusion is a process that uses a die in order to get a material with a constant cross-sectional cut. The die is what the material is pushed through in order to get the desired shape. Each product has a specific die that will create that shape and characteristic. Extrusion is used with materials such as plastic, aluminum, and dough. These products are either too brittle or too soft to be formed using bending or hammering, so in order to form the desired shapes extrusion is necessary.

2. Which of the following is a type of extrusion process?

a) Direct

b) Indirect

c) Impact

d) All of the mentioned

Answer: d

Explanation: Classification of extrusion processes are shown below.

3. Which of the following is true about the extrusion process?

a) Structure is homogeneous

b) No time is lost in changing the shape

c) Service life of extrusion tool is too high

d) Its leading end is in good shape as compared to rolling

Answer: b

Explanation: No time is lost in changing the shape as the dies may be readily removed in the process of extrusion.

4. In which extrusion process the direction of flow of metal is in same direction as that of ram?

a) Direct

b) Indirect

c) Impact

d) Hydrostatic

Answer: a

Explanation: Direction extrusion is a process in which the metal billet, placed in a container is forced by a ram to pass through a die. In this type, the direction of flow of metals is, in same as that of movement of ram. The punch closely fits the die cavity to prevent the backward flow of the material.

5. In direct extrusion process at higher temperature which of the following is used to avoid friction?

a) Oil

b) Lubricants

c) Molten glasses

d) Wax

Answer: c

Explanation: For steels, stainless steel, and high temperature materials, glass is a good excellent lubrication. The reasons for this are as follows. i. Glass contains its viscosity at elevated temperatures, ii. Has good wetting characteristics, and 3. Glass acts as a thermal barrier between the billet, the container and the die, thus minimizing cooling.

6. Which of the following is not used because of the problem of handling extruded metal coming out through moving ram?

a) Direct

b) Indirect

c) Impact

d) Hydrostatic

Answer: b

Explanation: Indirect extrusion method is not used because of the problem of handling extruded metal coming out through moving ram.

7. Which of the following is not a cold extrusion process?

a) Cold extrusion forging

b) Impact extrusion

c) Hydrostatic extrusion

d) Cold rolling

Answer: c

Explanation: Cold extrusion is done at room temperature or near room temeprature. The processes, impact extrusion, hydrostatic extrusion and cold extrusion forging are the types of cold forging. The advantages of this over hot extrusion are the lack of oxidation, higher strength due to cold working, closer tolerances, and good surface finish.

8. In which of the following process frictional loss is eliminated at the billet container interface?

a) Direct

b) Indirect

c) Impact

d) Hydrostatic

Answer: d

Explanation: In hydrostatic extrusion process frictional loss is eliminated at the billet container interface. This elimination increases the quality of the product.

9. In which of the following process fluid medium is used to apply the load on the billet?

a) Direct

b) Indirect

c) Impact

d) Hydrostatic

Answer: d

Explanation: In hydrostatic extrusion process fluid medium is used to apply the load on the billet. As hydro stands for fluid and static for rest.

10. Extrusion is similar to?

a) Rolling

b) Forming

c) Welding

d) Casting

Answer: a

Explanation: Extrusion is similar rolling in producing constant cross-sectional shape.

11. Which defect arises due to high friction or high speed?

a) Tearing

b) Surface cracking

c) Tearing & Surface cracking

d) Flaking

Answer: c

Explanation: The defects such as, surface cracking and tearing, occurs with high friction or speed. These can also occur with stickling of billet material on die land. Material sticks, pressure increases, product stops and starts to move again. This produces circumferential cracks on surface like a bamboo stem.

12. Which of the following defect is also known as bamboo defect?

a) Blow hole

b) Cold shut

c) Surface cracking

d) Pipe defect

Answer: c

Explanation: Bamboo defects are periodic surface cracks that develop due to the extruded product sticking to the die land.

13. Which of the following defect tends to draw surface oxides and impurities towards the centre of billet?

a) Blow hole

b) Cold shut

c) Surface cracking

d) Pipe defect

Answer: d

Explanation: Pipe defect is the formation of sin hole at the end of the billet. It is associated with direct extrusion. The use of dummy blocks whose diameter is slightly less than that of the billet helps to avoid piping.

14. Which of the following defect is also known as fish tailing?

a) Surface cracking

b) Pipe defect

c) Tearing

d) Internal cracking

Answer: b

Explanation: In extrusion, the pipe defect is also termed as “tail pipe”, and “fish tailing”. It occurs during hot extrusion due to the presence of impurities and oxides.

15. The centre of the extruded product can develop cracks called as?

a) Centre cracking

b) Centre burst

c) Arrow headed fracture

d) All of the mentioned

Answer: d

Explanation: Cracks that are developed in the centre of extruded material is known as internal cracking. These are termed as “centre cracking”, “centre burst”, “chevron cracking”, and as “arrow head cracking”.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Deep Drawing”.

1. In which of the following process the work piece is pulled through a die resulting in reduction of area?

a) Forging

b) Drawing

c) Forming

d) Extrusion

Answer: b

Explanation: Large quantities of wires, rods, tubes and other sections are produced by drawing process which is basically a cold working process. In this process, the material is pulled through a die in order to reduce it to the desired shape and size. In a typical wire drawing operation, one end of the wire is reduced and passed through the opening of the die, gripped and pulled to reduce its diameter.

2. In drawing which angle allows the introduction of lubricant into the working zone?

a) Entrance angle

b) Die angle

c) Semi-die angle

d) Relief angle

Answer: a

Explanation: The entrance angle provides the entry zone to allow the introduction of lubricant into the working zone and to protect the work material against scoring by die edges. The angle is usually about 40°.

3. Degree of drawing is measured in terms of?

a) Reduction in stress

b) Reduction in force

c) Reduction in area

d) Reduction in strain

Answer: c

Explanation: The degree of drawing is measured in terms of “reduction of area” which is defined as the ratio of the difference cross-sectional area before and after drawing to the initial cross-sectional area.

4. The maximum reduction in cross sectional area per pass is?

a) 45%

b) 63%

c) 55%

d) 67%

Answer: b

Explanation: For perfectly plastic material, the ideal maximum reduction per pass is 63%. For a strain hardening material, the ideal maximum reduction per pass depends on the strain hardening coefficient. For example, for n = 0.19, then the maximum reduction per pass is 69.5%.

5. Which of the following die is used in drawing flat strips?

a) Square shaped

b) Rectangular shaped

c) Circular shaped

d) Wedge shaped

Answer: d

Explanation: Wedge shaped die is used in drawing flat strips.

6. As the reduction increases, drawing force must be?

a) Decreases

b) Increases

c) Does not change

d) First increases and then decreases

Answer: b

Explanation: With the increase in reduction the drawing force increases.

7. Which of the following angle influence the drawing force and the quality of drawn products?

a) Entrance angle

b) Die angle

c) Relief angle

d) Flake angle

Answer: b

Explanation: Die angle influence the drawing force and the quality of drawn products. Die angle should be kept appropriate for better surface finish.

8. Degree of drawing is given by the expression?

a) (d i -d f )

b) (A i -A f )

c) (A i -A f )/A i

d) 1-((d f -d i ))

Answer: c

Explanation: Degree of drawing is given by the expression(A i -A f )/A i . Where d is the diameter of tube.

9. If the initial diameter is 50mm2 and the final diameter after drawing is 40mm 2 , then the degree of drawing is?

a) .64

b) .20

c) .80

d) .36

Answer: d

Explanation: Degree of drawing is given by [1- (d f /d i ) 2 ]. Where d is the diameter of tube.

10. If the degree of drawing is 0.5 and the initial area is 100mm 2 then the final area in mm 2 is equal to?

a) 50

b) 60

c) 40

d) 30

Answer: a

Explanation: Degree of drawing= (A i -A f )/A i . Where d is the diameter of tube, A is area.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Fundamentals Of Metal Casting”.

1. ‘V’ or ‘f’ marked surfaces on a casting indicates?

a) Camber allowance

b) Machining allowance

c) Draft allowance

d) Shrinkage allowance

Answer: b

Explanation: Surfaces of castings required to be machined, are made to dimensions more than that indicated on the working drawings. The extra amount of material provided on the surfaces is called machine finish allowance and V or f is indicated on these surfaces.

2. Considering the shrinkage allowance, the amount of pattern, when compared to casting is?

a) larger than casting

b) smaller than casting

c) same as casting

d) equal to casting

Answer: a

Explanation: Shrinkage allowance is a correction for solidification shrinkage of metal and its contraction during cooling. It is larger than the casting to provide space for total contraction.

3. The process of removing unwanted material from the casting is called?

a) fettling

b) cleaning

c) finishing

d) blowing

Answer: a

Explanation: Fettling is the complete process of the cleaning of the casting. It involves removal o the cores, gates, risers, cleaning of the as surface and chipping of any of the unnecessary projection on the surfaces. Core can be removed simply by knocking of it with an iron bar or by means of a cone vibrator. Gates and risers can be removed by hammering, chipping, hack sawing, or by flame or arc cutting.

4. In the following type of foundry, melting unit, as well as balance equipment, are installed to the casting of the particular metal is?

a) jobbing foundry

b) ferrous foundry

c) mass production foundry

d) non-ferrous foundry

Answer: b

Explanation: A jobbing foundry is one that produces a casting or a small number of castings of a given kind as per order. Mass production foundries have automatic molding, pouring and finishing lines with a little or no manual handling. The melting unit, as well as balance equipment in the foundry, is installed in ferrous foundry to suit the casting of particular metal.

5. Which of the following is used for making the hollow cavities in the casting?

a) chaplet

b) vent rod

c) core

d) chill

Answer: c

Explanation: For producing a casting with internal cavities or passages, cores which are made of sand are utilized. Cores are placed in the mold cavity to form the interior surface of the casting and are removed from the finished part during fettling process.

6. What is the limitation of oil as a binder?

a) at lower temperature, bond between sand mix and oil becomes strong

b) at higher temperature, bond between sand mix and oil becomes strong

c) should be added in high volumes

d) quickly hardens

Answer: b

Explanation: At higher temperatures the bond between sand mix and oil becomes hard and brittle there by weakening the sand mix. So, care should be taken about the rate and temperature of baking of oil sands.

7. Cereals are added to the molding sand to improve which of the following?

a) hot strength

b) porosity

c) green strength

d) edge hardness

Answer: c

Explanation: The role of cereals on imparting an amount of green strength in oil sands has been mentioned. Cereals are used because they are less harmful than clays form the point of view of baked strength in oil sand cores. Starch is capable of imparting a higher green strength than dextrin for the same amount of moisture.

8. To improve the surface finish of castings, which of the following additive is used in the molding sand?

a) resins

b) sea coal

c) oils

d) wood flour

Answer: b

Explanation: Resins produces good bonding strength between the sand grains, oils are used as binders, wood flour is cellulose material used to overcome sand expansion defects and seal coal is finely ground soft coal used for surface finish of castings.

9. To permit the escape of gases generated in the mold, which of the following are provided?

a) vent holes

b) chills

c) chaplets

d) core print

Answer: a

Explanation: Chaplets are used to support the cores inside the mold cavity to take care of its own weight and overcome the metallostatic force, core print is used to create openings and various shaped cavities in the castings, and vent hole, a small opening in the mold to facilitate the escape of air and gases.

10. Which of the following is used for making the hollow cavities in the casting?

a) chaplet

b) vent rod

c) core

d) chill

Answer: c

Explanation: Chaplets are used to support the cores inside the mold cavity to take care of its own weight and overcome the metallostatic force, core is a separate part of the mold, made of sand and generally baked, which is used to create openings and various shaped cavities in the castings.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Metal Solidification and Fluid Flow”.

1. Grains created when a metal solidifies rather slowly in the presence of a steep temperature gradient fall in the category of?

a) equiaxed grains

b) columnar grains

c) elongated grains

d) planer grains

Answer: b

Explanation: Columnar grains are long, thin, coarse grains created when a metal solidifies rather slowly in the presence of a steep temperature gradient. Relatively few nuclei are available when columnar grains are produced.

2. Vacancies are _____________

a) planer defects

b) line defects

c) point defects

d) volume defects

Answer: c

Explanation: Vacancy defect is the simplest point defect. In this system, an atom is missing from its regular atomic site, vacancies are formed during solidification due to vibration of atoms.

3. Scanning tunneling microscope is a tool usually used to analyze an image at ____________

a) sub-atomic level

b) atomic level

c) micro level

d) macro level

Answer: b

Explanation: Scanning tunneling microscope  is a technique that has been used for the surface study of nanostructures using the chemical composition of atoms and molecules in NPs to image surfaces at the atomic level. High-resolution material contrast has been successfully demonstrated in STM photon emission maps that correlate closely with the topographi image.

4. What are the examples of line defect?

a) vacancies

b) dislocations

c) twins

d) stacking faults

Answer: b

Explanation: Line imperfections, or dislocations, in crystalline solids are defects that cause lattice distortion centered around a line.

5. A mixture of a metal and a non-metal is called?

a) composite

b) alloy

c) dislocation

d) cermet

Answer: b

Explanation: A mixture of metal and non-metal is termed as an alloy, whereas a combination of two different materials  is called as composite.

6. If there are 930 grains per mm 2 on a photomicrograph of a metal at 2X, what is the ASTM grain size number of the metal?

a) 6

b) 7

c) 7.92

d) 8.91

Answer: d

Explanation: If there are 930 grains per mm 2 at 2X, then at 1X we will have

N ‘ =  2 (930 grains/mm 2 ) = 3720

therefore, N = N ‘ /15.5 = 3720/15.5 = 240

240 = 2 n-2

log 240 = 

2.380 = 

n = 8.91.

7. An ASTM grain size determination is being made from a photomicrograph of a metal at a magnification of 1X. What is the ASTM grain size number of the metal if there are 992 grains per square mm?

a) 6

b) 7

c) 7.92

d) 8.91

Answer: b

Explanation: N = 2 n-1

where, N = no of grains per square inch at 100X

n = ASTM grain size number

and N is obtained using the following expression:

N = N ‘ /15.5 where N ‘ = no. of grains per square mm at 1X

Thus, N = 992/15.5 = 64

or, 64 = 2 n-1

log 64 = 

n = 7.

8. Risers are also called __________

a) spure

b) runners

c) feeders

d) risers

Answer: c

Explanation: Risers also called feeders serve as reservoirs of molten metal to supply any molten metal necessary to prevent porosity due to shrinkage during solidification.

9. In a free-falling liquid, the cross-sectional area of the stream?

a) increases

b) decreases

c) remains constant

d) first increases and then decreases

Answer: b

Explanation: In a free falling liquid, the cross sectional area of the stream decreases as the liquid gains velocity downward.

10. If the pouring basin has a much larger cross-sectional area than the sprue bottom, then the velocity of the molten metal is?

a) low

b) high

c) normal

d) either high or low

Answer: a

Explanation: The molten metal flows through a sprue to a runner and a gate and fills the mold cavity. If the pouring basin has a much larger cross sectional area than the sprue bottom, then the velocity of the molten metal at the top of the pouring basin is very low and can be taken to be zero.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Foundries and Foundry Automation”.

1. Which of the following furnaces, are used extensively in foundries and have such advantages as a high rate of melting?

a) Induction

b) Electric arc

c) Crucible

d) Vacuum arc

Answer: b

Explanation: Electric-arc furnaces, are used extensively in foundries and have such advantages as a high rate of melting , much less pollution than other types of furnaces, and the ability to hold the molten metal for alloying purposes.

2. Which of the following furnaces, are especially useful in smaller foundries?

a) Induction

b) Electric arc

c) Crucible

d) Vacuum arc

Answer: a

Explanation: Induction furnaces, are especially useful in smaller foundries and produce smaller Composition-controlled melts.

3. Which of the following furnace consists of a crucible completely surrounded with a water-cooled copper coil?

a) coreless induction

b) electric arc

c) channel

d) vacuum arc

Answer: a

Explanation: The coreless induction furnace consists of a crucible surrounded with a water-Cooled copper coil through which a high-frequency current pass. Because there is a strong electromagnetic stirring action during induction heating, this type of furnace has excellent mixing characteristics for alloying and adding a new charge of metal.

4. Which of the following furnaces uses a low-frequency current?

a) coreless induction

b) electric arc

c) channel

d) vacuum arc

Answer: c

Explanation: The channel furnace, uses a low-frequency Current  and has a coil that surrounds only a small portion of the unit.

5. Channel furnaces are used in?

a) superheating

b) holding

c) duplexing

d) all of the mentioned

Answer: d

Explanation: Channel furnace are used in nonferrous foundries and are particularly suitable for  superheating ,  holding , and  duplexing .

6. Which of the following furnaces are heated with various fuels, such as commercial gases, fuel oil, and fossil fuel, as well as electricity?

a) Induction

b) Electric arc

c) Crucible

d) Vacuum arc

Answer: c

Explanation: Crucible furnaces, which have been used extensively throughout history, are heated with various fuels, such as commercial gases, fuel oil, and fossil fuel, as well as electricity. Crucible furnaces may be stationary, tilting, or movable.

7. Which of the following furnaces are basically vertical, refractory-lined steel vessels charged with alternating layers of metal, coke, and flux?

a) Cupolas

b) Electric arc

c) Crucible

d) Vacuum arc

Answer: a

Explanation: Cupolas are basically vertical, refractory-lined steel vessels charged with alternating layers of metal, coke, and flux. Although they require major investments and increasingly are being replaced by induction furnaces, cupolas operate continuously, have high melting rates, and produce large amounts of molten metal.

8. Which of the following technique involves magnetic suspension of the molten metal?

a) Cupolas

b) Levitation melting

c) Crucible

d) Induction melting

Answer: b

Explanation: Levitation melting involves magnetic suspension of the molten metal. An induction coil simultaneously heats a solid billet and stirs and confines the melt, thus eliminating the need for a crucible.

9. Which of the following is correct regarding “automation” in industry?

a) reduces the possibility of human error

b) minimizes labour cost

c) increases the production rate

d) all of the mentioned

Answer: d

Explanation: Automation minimizes labor, reduces the possibility of human error, increases the production rate, and attains higher quality levels.

10. Industrial robots are used in foundry operations for ___________

a) cleaning

b) riser cutting

c) mold venting

d) all of the mentioned

Answer: d

Explanation: Industrial robots are now used extensively in foundry operations, such as cleaning, riser cutting, mold venting, mold spraying, pouring, sorting, and inspection.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Heat Transfer-1”.

1. Rate of heat flow in conduction.

a) Is directly proportional to temperature gradient

b) Is inversely proportional to temperature gradient

c) Does not depend on temperature gradient

d) Does not depend on temperature gradient & inversely proportional to temperature gradient

Answer: a

Explanation: In conduction, heat transfer rate per unit area is proportional to a temperature gradient. Fourier’s law of conduction describes it as: q = -kA \(\frac{∂T}{∂x}\), where q = heat transfer rate, \(\frac{∂T}{∂x}\) = temperature gradient, k = thermal conductivity and the negative sign indicates heat flows downhill in temperature scale.

2. Thermal conductivity of silver in W/m-K is near about ___________

a) 210

b) 310

c) 410

d) 510

Answer: c

Explanation: Thermal conductivity of silver is nearly about 430 W/m-K at room temperature, for other materials, thermal conductivity values are tabulated below.

S.No. Material K, W/m-K

1. Diamond 2300

2. Silver 430

3. Copper 400

4. Gold 320

5. Aluminium 240

6. Iron 80

7. Glass 0.8

8. Brick 0.7

9. Water 0.61

10. Wood 0.17

11. Helium 0.15

12. Air 0.026

3. Thermal conductivity of copper in W/m-K is near about ___________

a) 210

b) 385

c) 485

d) 510

Answer: b

Explanation: Thermal conductivity of silver is nearly about 400 W/m-K at room temperature.

4. Thermal conductivity of aluminum in W/m-K is near about ___________

a) 202

b) 302

c) 410

d) 502

Answer: a

Explanation: Thermal conductivity of silver is nearly about 240 W/m-K at room temperature.

5. Which of the following is also known as transport property?

a) Pressure

b) Thermal conductivity

c) Resistance

d) Electrical conductivity

Answer: b

Explanation: Thermal conductivity of material is also known as transport property. It is an intrinsic property of a material which relates its ability to conduct heat. Heat transfer by conduction involves the transfer of energy within a material without any motion of the material as a whole.

6. With the use of thermal grease contact resistance will?

a) Increase

b) Decrease

c) Remains constant

d) First increases and then decreases

Answer: d

Explanation: Thermal grease reduces contact resistance. Silicon oil is thermal grease which decreases contact resistance.

7. Silicon oil applied between two contact surfaces will?

a) Increase contact resistance

b) Decrease contact resistance

c) Increase gap void

d) Does not depend upon contact resistance

Answer: b

Explanation: Silicone oil can act as a highly effective lubricant for sliding microelectromechanical system  surfaces, increasing operational lifetime for devices with interacting surfaces, thus degrading electrical contact resistance.

8. When temperature of mercury liquid increases, its thermal conductivity?

a) Decreases

b) Increase

c) Remains constant

d) First increases and then decreases

Answer: a

Explanation: Thermal conductivity of liquid is inversely proportional to temperature. When temperature of mercury liquid increases, its thermal conductivity decreases.

9. When molecular weight of mercury liquid increases, its thermal conductivity?

a) Decreases

b) Increase

c) Remains constant

d) First increases and then decreases

Answer: a

Explanation: Molecular weight of liquid is inversely proportional to temperature. Thermal conductivity of liquid is inversely proportional to temperature.

10. Thermal conductivity of diamond is more than that of glass. It is because ___________

a) diamond has crystalline structure

b) glass has non crystalline structure

c) diamond and glass both have crystalline structure

d) diamond has amorphous structure

Answer: a

Explanation: Crystalline structures have more thermal conductivity due to lattice vibration. Thermal conductivity of liquid is inversely proportional to temperature.

This set of Manufacturing Science Puzzles focuses on “Heat Transfer-2”.

1. Ratio of rate of heat conduction to the rate of internal energy storage is in solid is known as?

a) Biot number

b) Drag coefficient

c) Eckert number

d) Fourier number

Answer: d

Explanation: Fourier number is the ratio of heat conduction to the rate of heat storage. The significance of Fourier number is 1. It signifies the degree of penetration of heating or cooling effect, 2. It is a measure of heat conducted through a body relative to heat stored.

2. Ratio of pressure drop for internal flow through ducts is known as?

a) Friction factor

b) Grashof number

c) Colburn factor

d) Nusselt number

Answer: a

Explanation: Friction factor µ is defined as the ratio between the force required to move a section of pipe and the vertical contact force applied by the pipe on the seabed, in simpler terms, it is the ratio of pressure drop for internal flow though ducts.

3. Ratio of buoyancy to viscous forces is known as?

a) Prandtl number

b) Grashof number

c) Colburn factor

d) Nusselt number

Answer: b

Explanation: Grashof number in natural convection is analogous to the Reynolds number is forced convection. Grashof number indicates the ratio of the buoyancy force to the viscous force. Higher Gr number means increased natural convection flow.

4. Which of the following is known as the dimensionless heat transfer coefficient?

a) Friction factor

b) Grashof number

c) Colburn factor

d) Weber number

Answer: c

Explanation: Colburn factor obtained from the Reynold-Colburn analogy relates to the local skin friction coefficient  to the local convective heat transfer coefficient.

5. Which of the following is known as the dimensionless heat transfer coefficient?

a) Friction factor

b) Grashof number

c) Nusselt number

d) Prandtl number

Answer: c

Explanation: Nusselt number is a dimensionless number and it is defined as the ratio of convective heat flux to the conductive heat flux . Convection in fluid = conduction in fluid + advection in fluid . So, practically we can understand it as a comparison of heat taken by fluid due to moving fluid and heat taken by a static fluid when flowing over a heated plate .

6. Ratio of convection heat transfer to conduction is known as?

a) Friction factor

b) Grashof number

c) Colburn factor

d) Nusselt number

Answer: a

Explanation: The Nusselt number is the ratio of convective to conductive heat transfer across a boundary.

Nu = \(\frac{hl}{k}\), where, h = heat transfer coefficient, l = characteristic length and k = thermal conductivity.

7. Product of Prandtl number and Reynolds number is also known as?

a) Peclet number

b) Prandtl number

c) Rayleigh number

d) Biot number

Answer: a

Explanation: Peclet number is the product of Prandtl number and Reynolds number, in other sense, it is the ratio of the heat transfer by convection to the heat transferred by conduction. So, you can consider a pipe with some wall thickness. The wall conducts heat to the fluid. While the heat can also be carried away by the fluid in motion which is called as advection. If the advection term is dominant, then the Peclet number is going to large and thus the hat transfer from the wall is of less importance. Conversely, the heat transfer form the wall to the fluid can be of higher importance in the case of a smaller Peclet number.

8. Ratio of molecular diffusivity to thermal diffusivity is also known as?

a) Biot number

b) Prandtl number

c) Rayleigh number

d) Biot number

Answer: b

Explanation: Prandtl number as explained by others here, is a dimensionless number, which is the ratio of molecular diffusivity of momentum to molecular diffusivity of heat. It shows the relative thickness of the velocity boundary layer to the thermal boundary layer.

9. Product of Grashof and Prandtl is known as?

a) Peclet number

b) Biot number

c) Rayleigh number

d) Reynolds number

Answer: c

Explanation: Rayleigh number is the product of Grashof and Prandtl number.

10. Ratio of inertia to viscous forces is known as?

a) Stanton number

b) Prandtl number

c) Rayleigh number

d) Reynolds number

Answer: d

Explanation: The Reynolds number is the ratio of inertial forces to viscous forces. The Reynolds number is a dimensionless number used to categorize the fluids systems in which the effect of viscosity is important in controlling the velocities or the flow pattern of a fluid.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Fluid Flow and Heat Transfer”.

1. The flow of fluid which is highly chaotic is called as?

a) Laminar

b) Turbulence

c) Reynolds

d) Irrotational flow

Answer: b

Explanation: Turbulent flow is chaotic. However, not all chaotic flows are turbulent. Turbulent flow is characterized by the irregular movement of particles of the fluid. In contrast to laminar the fluid does not flow in parallel layers, the lateral mixing is very high, and there is a disruption between the layers. Turbulence is also characterized by recirculation, eddies, and apparent randomness, in other sense, in turbulent flow-the speed of the fluid at a point is continuously undergoing changes in both magnitude and direction.

2. The capability of molten metal to fill mold cavities is called ____________

a) viscosity

b) fluidity

c) turbulence

d) velocity

Answer: b

Explanation: Fluidity is the property of a fluid which allows fluid to flow. In general understanding, one can say, the fluidity is inversely proportional to viscosity. Factors affecting fluidity in casting are as follows.

i. Modulus: fluidity length increases as the modulus  of the casting increases

ii. Section thickness: larger thickness of section results in higher fluidity

iii. Heat transfer coefficient: a reduction in the rate of heat transfer will increase fluidity

iv. Superheating: the temperature increment above the melting point increases fluidity

v. Mould temperature: higher mould temperature increases fluidity

vi. Pouring rate: lower pouring rates decrease fluidity because of larger cooling.

3. The liquid metal reduces its fluidity mainly due to?

a) high viscosity

b) high friction factor

c) high surface tension

d) high turbulence

Answer: c

Explanation: A high surface tension of the liquid metal reduces fluidity. Because of this, oxide films on the surface of the molten metal have a significant adverse effect on fluidity.

4. The slower the rate of pouring molten metal into the mold, the nature of fluidity will be?

a) lower

b) higher

c) constant

d) either higher or lower

Answer: a

Explanation: The slower the rate of pouring molten metal into the mold, the lower is the fluidity because of the higher rate of cooling when poured slowly.

5. With an increase in the thickness of insulation around a circular pipe, heat loss to surrounding due to ____________

a) convection increase, while that the due to conduction decreases

b) convection decrease, while that due to conduction increases

c) convection and conduction decreases

d) convection and conduction increases

Answer: b

Explanation: By increasing the thickness of insulation, the convection heat transfer co-efficient decreases and heat loss by the convection also decreases. These both cases are limited for the critical thickness of insulation.

6. For a given heat flow and for the same thickness, the temperature drop across the material will be maximum for ____________

a) copper

b) steel

c) glass-wool

d) refractory brick

Answer: c

Explanation: Q = -kA 

Qdx/A = -kdT

therefore, kdT = constant or dT ∞ 1/k.

7. In descending order of magnitude, the thermal conductivity of:

i. Pure iron,

ii. Liquid water,

iii. Saturated water vapour, and

iv. Pure aluminium

can be arranged as?

a) , ,  and 

b) , ,  and 

c) , ,  and 

d) , ,  and 

Answer: c

Explanation: Thermal conductivity of values at room temperature are tabulated below:

S.No. Material Thermal Conductivity 

1 Iron 79.5

2 Water 0.6

3 Water vapour 0.025

4 Aluminium 150

8. A copper block and an air mass block having similar dimensions are subjected to symmetrical heat transfer from one face of each block. The other face of the block will be reaching the same temperature at a rate is?

a) Faster in air block

b) Faster in copper block

c) Equal in air as well as copper block

d) Cannot be predicted with the given information

Answer: b

Explanation: Copper has a thermal conductivity of 400 W/m-K and air has an value of 0.026 W/m-K.

9. Consider the following statements:

The Fourier heat conduction equation Q = -kA presumes

i. Steady-state conditions

ii. Constant value of thermal conductivity.

iii. Uniform temperatures at the wall surfaces

iv. One-dimensional heat flow.

Which of the above statements are correct?

a) ,  and  are correct

b) ,  and  are correct

c) ,  and  are correct

d) ,  and  are correct

Answer: d

Explanation: Thermal conductivity may constant or variable.

10. The outer surface of a long cylinder is maintained at constant temperature. The cylinder does not have any heat source. The temperature in the cylinder will?

a) Increase linearly with radius

b) Decrease linearly with radius

c) Be independent of radius

d) Vary logarithmically with radius

Answer: d

Explanation: In case of cylinder, in Q = -kA , thus indicating the logarithmic change.

11. For conduction through a spherical wall with constant thermal conductivity and with inner side temperature greater than outer wall temperature, , what is the type of temperature distribution?

a) Linear

b) Parabolic

c) Hyperbolic

d) Logarithmic

Answer: c

Explanation: Temp distribution would be t – t 1 .

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Jigs and Fixtures”.

1. With the use of Jigs and fixture total cost of production

a) Increases

b) Decreases

c) Remains same

d) Jigs are not used in any production process

Answer: b

Explanation: Total cost of production decreases with the use of jigs and fixture. Jigs are holding device and fixture are generally used for the bigger work piece.

2. With the use of Jigs and fixture rate of production will

a) Increase

b) Decrease

c) Remains same

d) Jigs are not used in any production process

Answer: a

Explanation: Total production increase with the use of jigs and fixture. Jigs are holding device and fixture are generally used for the bigger work piece.

3. Jigs and fixture increases the accuracy of the parts.

a) True

b) False

Answer: a

Explanation: Accuracy of parts increases by use of jigs and fixture. Jigs are holding device and fixture are generally used for the bigger work piece.

4. Jigs And fixture are used to provide interchangeability.

a) True

b) False

Answer: a

Explanation: Interchangeability of parts increases by use of jigs and fixture. Jigs are holding device and fixture are generally used for the bigger work piece.

5. With the use of Jigs and fixture quality control expenses will

a) Reduce

b) Increases

c) Jigs and fixture are not used in any production process

d) None of the mentioned

Answer: a

Explanation: Jigs and fixture increase accuracy. Jigs are holding device and fixture are generally used for bigger work piece. Interchangeability of parts increases by use of jigs and fixture.

6. With the use of Jigs and fixture

a) Labour cost decreases

b) Labour cost increases

c) Labour cost decreases

d) None of the mentioned

Answer: a

Explanation: Less skilled labour required. Interchangeability of parts increases by use of jigs and fixture. Jigs and fixture increases accuracy. Jigs are holding device and fixture are generally used for bigger work piece.

7. Which of the following is not correct about fixture?

a) It is used to hold the work

b) It is used to position the work the work

c) It assures high accuracy of parts

d) It is used to guide the cutting tool

Answer: d

Explanation: Fixture do not guide cutting tool. jigs and fixture increases accuracy. Jigs are holding device and fixture are generally used for bigger work piece.

8. Which of the following is not correct about jig?

a) It is used to hold the work

b) It is used to position the work the work

c) It is used to guide the cutting tool

d) None of the mentioned

Answer: d

Explanation: All of the mentioned are correct about jigs. Jigs and fixture increases accuracy. Jigs are holding device and fixture are generally used for bigger work piece.

9. In which of the following operation jigs are preferred over fixture?

a) Drilling

b) Turning

c) Milling

d) Grinding

Answer: a

Explanation: Jigs and fixture increases accuracy. Jigs are holding device and fixture are generally used for bigger work piece. Jigs are preferred over fixture in drilling because they also help in guidance of tool.

10. Number of degree of freedom of a workpiece in space is equal to

a) 10

b) 12

c) 14

d) 16

Answer: b

Explanation: Work piece has 16 degree of freedom. It can have 16 different movements.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Engineering Metrology And Instrumentations”.

1. Methods of mechanical surface treatments are

a) shot peening

b) laser shot peening

c) water jet peening

d) all of the mentioned

Answer: d

Explanation: The various methods of mechanical surface treatments includes

a) shot peening

b) laser shot peening

c) water jet peening

d) ultrasonic peening

e) roller burnishing

f) explosive hardening.

2. Mechanical plating is also called

a) clad bonding

b) peen plating

c) laser cladding

d) none of the mentioned

Answer: b

Explanation: In mechanical plating , fine metal particles are compacted over the workpiece surfaces by glass, ceramic, or porcelain beads that are propelled by rotary means .

3. Thermal spraying includes coatings of

a) carbides

b) ceramics

c) polymers

d) all of the mentioned

Answer: d

Explanation: Thermal spraying is a series of processes in which coatings of various metals, alloys, carbides, ceramics, and polymers are applied to metal surfaces by a spray gun with a stream heated by an oxyfuel flame, an electric arc, or a plasma arc.

4. In ________________ oxyfuel flame melts the wire and deposits it on the surface.

a) thermal wire spraying

b) thermal metal powder spraying

c) detonation gun

d) none of the mentioned

Answer: a

Explanation: The oxyfuel flame melts the wire and deposits it on the surface. The bond is of medium strength, and the process is relatively inexpensive.

5. Conversion coating is also called

a) anodizing

b) chemical reaction priming

c) coloring

d) none of the mentioned

Answer: b

Explanation: Conversion coating, also called chemical-reaction priming, is the process of producing a coating that forms on metal surfaces as a result of chemical or electrochemical reactions. Various metals  can be conversion coated. Oxides that naturally form on their surfaces represent a form of conversion coating.

6. Classification of paints are

a) enamels

b) lacquers

c) water based paints

d) all of the mentioned

Answer: d

Explanation: Paints generally are classified as

a) Enamels: Produce a smooth coat with a glossy or semi-glossy appearance.

b) Lacquers: Form a film by evaporation of a solvent.

c)Water-based paints: Applied easily, but have a porous surface and absorb water, making them more difficult to clean than the first two types.

7. The methods of metal cleaning are

a) mechanical cleaning

b) electrolytic cleaning

c) chemical cleaning

d) all of the mentioned

Answer: d

Explanation: None

8. Processes of chemical cleaning are

a) solution

b) saponification

c) emulsification

d) all of the mentioned

Answer: d

Explanation: Chemical cleaning usually involves the removal of oil and grease from surfaces. The operation consists of one or more of the following processes:

a) Solution: The soil dissolves in the cleaning solution.

b) Saponification: A chemical reaction converts animal or vegetable oils into a soap that is soluble in water.

c) Emulsification: The cleaning solution reacts with the soil or lubricant deposits and forms an emulsion; the soil and the emulsifier then become suspended in the emulsion.

d) Dispersion: The concentration of soil on the surface is decreased by surface active elements in the cleaning solution.

e) Aggregation: Lubricants are removed from the surface by various agents in the cleanser and are collected as large dirt particles.

9. Which of these are cleaning fluids?

a) alkaline solutions

b) emulsions

c) solvents

d) all of the mentioned

Answer: d

Explanation: Common cleaning fluids used in conjunction with electrochemical processes for more effective cleaning include the following:

a) Alkaline solutions: A complex combination of water-soluble chemicals, alkaline solutions are the least expensive and most widely used cleaning fluids in manufacturing operations. Small parts may be cleaned in rotating drums or barrels. Most parts are cleaned on continuous conveyors by spraying them with the solution and rinsing them with water.

b) Emulsions: Emulsions generally consist of kerosene and oil-in-water and various types of emulsifiers.

c) Solvents: Typically petroleum solvents, chlorinated hydrocarbons, and mineral spirits, solvents generally are used for short runs. Fire and toxicity are major hazards.

d) Hot vapors: Chlorinated solvents can be used to remove oil, grease, and wax. The solvent is boiled in a container and then condensed. This hot-vapor process is simple, and the cleaned parts are dry.

e) Acids, salts, and mixtures of organic compounds: These are effective in cleaning parts covered with heavy paste or oily deposits and rust.

10. Type of laser surface treatments are

a) heating

b) melting

c) vaporization

d) all of the mentioned

Answer: d

Explanation: Type of laser surface treatments are

a) heating

b) melting

c) vaporization

d) peening.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Quality Assurance”.

1. The basic difference between MRP and MRP-II is:

a) inventory

b) bom

c) finance

d) capacity planning

Answer: c

Explanation: MRP-II is related to finance.

2. Inventory record file gives the following information

a) lot size

b) machine details

c) customer name

d) none of the mentioned

Answer: a

Explanation: Only lot size is considered in inventory record file.

3. Bill of material structure is used to

a) calculate net requirements

b) calculate due dates

c) calculate man power requirements

d) all of the mentioned

Answer: a

Explanation: None.

4. Just in time manufacturing philosophy emphasizes on

a) man power

b) manufacturing

c) profit

d) inventory

Answer: d

Explanation: None.

5. Forecasting is used for

a) dependent demand items

b) independent demand items

c) all of the mentioned

d) none of the mentioned

Answer: b

Explanation: None.

6. CRP takes material requirements from MRP and converts to

a) standard hours of man power

b) standard hours of machine

c) standard hours of load

d) all of the mentioned

Answer: d

Explanation: None.

7. Capacity planning is concerned with

a) how many machines required

b) how much labour required

c) all of the mentioned

d) none of the mentioned

Answer: c

Explanation: None.

8. MRP-II system is called a closed loop system because it considers

a) inventory

b) finance

c) man power

d) none of the mentioned

Answer: b

Explanation: Only MRP-II system contains finance.

9. P.M.T.S include

a) M.T.M 

b) W.F.S 

c) B.M.T.S 

d) All of the mentioned

Answer: d

Explanation: None.

10. M.T.M is used to

a) improve existing methods

b) establish time standards

c) develop effective methods in advance of the beginning of production

d) all of the mentioned

Answer: d

Explanation: None.

11. For a small scale industry, the fixed cost per month is Rs. 5000. The variable cost per product is Rs. 20 and sales price is Rs. 30 per piece. The break even production per month will be

a) 300

b) 40

c) 500

d) 1000

Answer: c

Explanation: If x is the break even production per month, then

5000 + 20x = 30x

or, x = 500.

12. Two alternatives can produce a product. First has a fixed cost of Rs. 2000 and a variable cost of Rs. 20 per piece. The second method has a fixed cost of Rs. 1500 and a variable cost of Rs.30. The break even quantity between the two alternatives is

a) 25

b) 50

c) 75

d) 100

Answer: b

Explanation: If x is the break even quantity, then

2000 + 20x = 1500 + 30x

or, x = 50.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Automation Of Manufacturing Process”.

1. Wrist motion of y involves

a) right to left rotation of the object

b) up and down rotation of the object

c) twisting of the object about the arm axis

d) none of the mentioned

Answer: a

Explanation: Wrist motion always follows right hand rule.

2. Robots are specified by

a) pay load

b) dimension of work envelope

c) degree of freedom

d) all of the mentioned

Answer: d

Explanation: None.

3. Hydraulic drives are used for a robot when

a) high torque is required

b) high power is required

c) rapid motion of robot arm

d) all of the mentioned

Answer: d

Explanation: None.

4. The following type of robot is most suitable for pick and place operations

a) rectangular

b) cylindrical

c) spherical

d) jointed arm type

Answer: a

Explanation: The fixed-sequence robot, also called a pick-and-place robot, is programmed for a specific sequence of operations. Its movements are from point to point, and the cycle is repeated continuously.

5. A computer program that contains expertise in a particular domain is called an

a) automatic processor

b) intelligent planner

c) expert system processor

d) operations symbolizer

Answer: c

Explanation: None.

6. The knowledge base of an expert system includes both facts and

a) theories

b) heuristics

c) algorithms

d) analysis

Answer: b

Explanation: Heuristics is any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals.

7. A robot’s arm is also known as its

a) actuator

b) end effector

c) manipulator

d) servomechanism

Answer: c

Explanation: The manipulator is a mechanical unit that provides motions  similar to those of a human arm and hand.

8. Which type of actuator generates a good deal of power but tends to be messy?

a) electric

b) hydraulic

c) pneumatic

d) none of the mentioned

Answer: b

Explanation: None.

9. If a robot can alter its own trajectory in response to external conditions, it is considered to be

a) intelligent

b) mobile

c) non servo

d) open loop

Answer: a

Explanation: The intelligent robot, also called a sensory robot, is capable of performing some of the functions and tasks carried out by humans. It is equipped with a variety of sensors with visual  and tactile capabilities.

10. Programming a robot by physically moving it through the trajectory you want it to follow is called

a) contact sensing control

b) continuous path control

c) pick and place control

d) robot vision control

Answer: b

Explanation: None.

11. Reasoning from a goal state towards an initial state is called

a) backward chaining

b) bidirectional

c) breadth first

d) heuristic

Answer: a

Explanation: Heuristics is any approach to problem solving, learning, or discovery that employs a practical methodology not guaranteed to be optimal or perfect, but sufficient for the immediate goals.

12. Which device is mostly associated with automation?

a) flexible manufacturing

b) robots

c) computer graphics workstation

d) NC machine

Answer: b

Explanation: Only robots are associated with automation.

13. Choose the basic element for an automated machine tool

a) logic

b) NC tape programming

c) software

d) workstation

Answer: a

Explanation: None.

14. Choose the robot component from the following

a) micro computer

b) coaxial cable

c) arm

d) software

Answer: c

Explanation: Arm is the major component of a robot.

15. A configuration for a robot is

a) octagonal

b) oblong

c) square

d) spherical

Answer: d

Explanation: None.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Computer Aided Manufacturing”.

1. CAD/CAM is the relationship between

a) science and engineering

b) manufacturing and marketing

c) design and manufacturing

d) design and marketing

Answer: c

Explanation: None

2. The process in which the detailed specifications materials, dimensions, tolerances and surface rough is made is known as

a) decision process

b) analysis process

c) implementation process

d) refinement process

Answer: c

Explanation: Decision process is the cognitive process resulting in the selection of a belief or a course of action among several alternative possibilities while implementation process is the detailed specifications materials, dimensions, tolerances and surface rough is made.

3. Which two disciplines are tied by a common database?

a) documentation and geometric modeling

b) CAD and CAM

c) drafting and documentation

d) none of the mentioned

Answer: b

Explanation: Because of their joint benefits, computer- aided design and computer-aided manufacturing are often combined into CAD/ CAM systems. This combination allows the transfer of information from the design stage to the stage of planning for manufacture, without the need to reenter the data on part geometry manually.

4. The term that is used for geometric modelling like solid modelling, wire frame modelling and drafting is known as

a) software package

b) operating system

c) application software

d) none of the mentioned

Answer: a

Explanation: Software package is used for geometric modelling like solid modelling, wire frame modelling and drafting while operating system is is software that manages computer hardware and software resources and provides common services for computer programs.

5. The system environment in a mainframe computer consists of

a) central processing

b) storage devices

c) printers and plotters

d) both central processing and storage devices

Answer: d

Explanation: None

6. The nerve center or brain of any computer system is known as

a) CPU

b) Storage device

c) ALU

d) Monitor

Answer: a

Explanation: None

7. Locating devices are classified as

a) text input device

b) graphic device

c) all of the mentioned

d) none of the mentioned

Answer: b

Explanation: GDI is responsible for tasks such as drawing lines and curves, rendering fonts and handling palettes.

8. A potentiometric device that contains sets of variable registers which feed signals that indicate the device position to the computer is known as

a) track ball

b) mouse

c) joystick

d) all of the mentioned

Answer: c

Explanation: None

9. Which of the following devices do not produce a hard copy?

a) impact printers

b) plotters

c) CRT terminals

d) non-impact printers

Answer: c

Explanation: CRT terminals always plot graphics or images.

10. The software that is used to control the computer’s work flow, organize its data and perform house keeping functions is known as

a) operating software

b) graphics software

c) application software

d) programming software

Answer: a

Explanation: Operating software is used to control the computer’s work flow, organize its data and perform house keeping functions.

Graphics software is used to provide users with various functions to perform geometric modelling and construction.

Application software performs the data entry, design, analysis, drafting and manufacturing functions.

Programming software enables the to implement custom application or modify the system for specialized needs.

11. The software that is used to provide the users with various functions to perform geometric modelling and construction is known as

a) operating software

b) graphics software

c) application software

d) programming software

Answer: b

Explanation: Operating software is used to control the computer’s work flow, organize its data and perform house keeping functions.

Graphics software is used to provide users with various functions to perform geometric modelling and construction.

Application software performs the data entry, design, analysis, drafting and manufacturing functions.

Programming software enables the to implement custom application or modify the system for specialized needs.

12. The software that performs the data entry, design, analysis, drafting and manufacturing functions is known as

a) operating software

b) graphics software

c) application software

d) programming software

Answer: c

Explanation: Operating software is used to control the computer’s work flow, organize its data and perform house keeping functions.

Graphics software is used to provide users with various functions to perform geometric modelling and construction.

Application software performs the data entry, design, analysis, drafting and manufacturing functions.

Programming software enables the to implement custom application or modify the system for specialized needs.

13. The software that enables the to implement custom application or modify the system for specialized needs is known as

a) operating software

b) graphics software

c) application software

d) programming software

Answer: d

Explanation: Operating software is used to control the computer’s work flow, organize its data and perform house keeping functions.

Graphics software is used to provide users with various functions to perform geometric modelling and construction.

Application software performs the data entry, design, analysis, drafting and manufacturing functions.

Programming software enables the to implement custom application or modify the system for specialized needs.

14. Following is not an operating system software

a) Windows

b) UNIX

c) VAX/VMS

d) IDEAS

Answer: d

Explanation: Except IDEAS all are the operating systems.

15. The basic geometric building blocks provided in a CAD/CAM package are

a) points

b) lines

c) circles

d) all of the mentioned

Answer: d

Explanation: None

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Computer Integrated Manufacturing”.

1. During the execution of a CNC part program block NO20 GO2 X45.0 Y25.0 R5.0 the type of tool motion will be

a) circular Interpolation – clockwise

b) circular Interpolation – counterclockwise

c) linear Interpolation

d) rapid feed

Answer: a

Explanation: Given:-NO20 GO2 X45.0 Y25.0 R5.0

Here term X45.0 Y25.0 R5.0 will produce circular motion because radius is consider in this term and GO2 will produce clockwise motion of the tool.

2. In an NC machining operation, the tool has to be moved from point  to point  along a circular path with centre at . Before starting the operation, the tool is at . The correct G and N codes for this motion are

a) N010GO3X7.0Y2.0I5.0J2.0

b) N010GO2X7.0Y2.0I5.0J2.0

c) N010GO1X7.0Y2.0I5.0J2.0

d) N010GOOX7.0Y2.0I5.0J2.0

Answer: b

Explanation: Given : Initial point , Final point , Centre 

So, the G, N codes for this motion are N010GO2X7.0Y2.0 15.0J2.0

where, GO2 ” Clockwise circular interpolation

X7.0Y2.0 ” Final point

I5.0J2.0 ” Centre point.

3. The tool of an NC machine has to move along a circular arc from  to  while performing an operation. The centre of the arc is at . Which one of the following NC tool path command performs the above mentioned operation?

a) N010 GO2 X10 Y10 X5 Y5 R5

b) N010 GO3 X10 Y10 X5 Y5 R5

c) N010 GO1 X5 Y5 X10 Y10 R5

d) N010 GO2 X5 Y5 X10 Y10 R5

Answer: a

Explanation: N010 “represent start the operation

GO2 “represent circular  interpolation

X10Y10 “represent final coordinates

X5Y5 “represent starting coordinate

R5 “represent radius of the arc

So, NC tool path command is, N010 GO2 X10 Y10 X5 Y5 R5.

4. NC contouring is an example of

a) continuous path positioning

b) point-to-point positioning

c) absolute positioning

d) incremental positioning

Answer: a

Explanation: NC contouring is a continuous path positioning system. Its function is to synchronize the axes of motion to generate a predetermined path, generally a line or a circular arc.

5. Match the following:

NC code      Definition

P. M05     1. Absolute coordinate system

Q. G01     2. Dwell

R. G04     3. Spindle stop

S. G09     4. Linear interpolation

a) P-2, Q-3, R-4, S-1

b) P-3, Q-4, R-1, S-2

c) P-3, Q-4, R-2, S-1

d) P-4, Q-3, R-2, S-1

Answer: c

Explanation: NC code Definition

P. M05 3. Spindle stop

Q. G01 4. Linear interpolation

R. G04 2. Dwell

S. G09 1. Absolute coordinate system

So, correct pairs are, P-3, Q-4, R-2, S-1.

6. In a CNC program block, N002 GO2 G91 X40 Z40……,GO2 and G91 refer to

a) circular interpolation in counterclockwise direction and incremental dimension

b) circular interpolation in counterclockwise direction and absolute dimension

c) circular interpolation in clockwise direction and incremental dimension

d) circular interpolation in clockwise direction and absolute dimension

Answer: c

Explanation: GO2 represent circular interpolation in clockwise direction.

G91 represent incremental dimension.

7. Numerical control ___________

a) applies only to milling machines

b) is a method for producing exact number of parts per hour

c) is a method for controlling by means of set of instructions

d) none of the mentioned

Answer: c

Explanation: NC is a method for controlling by means of set of instructions.

CNC performs the data processing functions.

8. Computer will perform the data processing functions in

a) NC

b) CNC

c) DNC

d) None of the mentioned

Answer: b

Explanation: NC is a method for controlling by means of set of instructions.

CNC performs the data processing functions.

9. Control loop unit of M.C.U is always

a) a hardware unit

b) a software unit

c) a control unit

d) none of the mentioned

Answer: a

Explanation: None.

10. The repeatability of NC machine depends on

a) control loop errors

b) mechanical errors

c) electrical errors

d) none of the mentioned

Answer: b

Explanation: None.

11. Rotation about Z-axis is called

a) a-axis

b) b-axis

c) c-axis

d) none of the mentioned

Answer: c

Explanation: Rotation about X-axis is called a-axis.

Rotation about Y-axis is called b-axis.

Rotation about Z-axis is called c-axis.

12. Rotation of spindle is designated by one of the following axis:

a) a-axis

b) b-axis

c) c-axis

d) none of the mentioned

Answer: d

Explanation: None.

13. The linking of computer with a communication system is called

a) networking

b) pairing

c) interlocking

d) assembling

Answer: a

Explanation: Networking is the practice of linking two or more computing devices together for the purpose of sharing data.

Pairing is the linking of computer with a communication system.

Interlocking is to fit into each other, as parts of machinery, so that all action is synchronized.

14. The process of putting data into a storage location is called

a) reading

b) writing

c) controlling

d) hand shaking

Answer: b

Explanation: Reading is the process of copying data from a memory location.

Writing is the process of putting data into a storage location.

15. The process of copying data from a memory location is called

a) reading

b) writing

c) controlling

d) hand shaking

Answer: a

Explanation: Reading is the process of copying data from a memory location.

Writing is the process of putting data into a storage location.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Product Design And Process Selection”.

1. Designs are periodically modified to

a) improve product performance

b) strive for zero-based rejection and waste

c) make products easier and faster to manufacture

d) all of the mentioned

Answer: d

Explanation: Designs are periodically modified to

a) Improve product performance

b) Strive for zero-based rejection and waste

c) Make products easier and faster to manufacture

d) Consider new materials and processes that are continually being developed.

2. The expected qualities of a product are

a) it satisfies the needs and expectations of the customer

b) it has a pleasing appearance and handles well

c) it has high reliability and functions safely over its intended life

d) all of the mentioned

Answer: d

Explanation: Generally, however, a high-quality product is considered to have at least the following characteristics:

a) it satisfies the needs and expectations of the customer

b) it has a pleasing appearance and handles well

c) it has high reliability and functions safely over its intended life

d) it is compatible with and responsive to the customer’s capabilities and working environment

e) installation, maintenance, and future improvements are easy to perform and at low cost.

3. The life cycle of a product includes

a) extraction of natural resources

b) processing of raw materials

c) manufacturing of products

d) all of the mentioned

Answer: d

Explanation: The life cycle involves consecutive and interlinked stages of a product or a service, from the very beginning to its disposal or recycling, and includes the following:

a) extraction of natural resources

b) processing of raw materials

c) manufacturing of products

d) transportation and distribution of the product to the customer

e) use, maintenance, and reuse of the product

f) recovery, recycling, and reuse of the components of the product.

4. Life-cycle engineering is also called

a) green design

b) expensive design

c) easy design

d) none of the mentioned

Answer: a

Explanation: The major aim of life-cycle engineering  is to consider reusing and recycling the components of a product, beginning with the earliest stage: product design. Life-cycle engineering is also called green design or green engineering.

5. Sustainable manufacturing is required for

a) conserving resources

b) proper maintenance

c) reuse

d) all of the mentioned

Answer: d

Explanation: The concept of sustainable manufacturing emphasizes the need for conserving resources, particularly through proper maintenance and reuse.

6. The mechanical properties of good product material are

a) strength

b) toughness

c) ductility

d) all of the mentioned

Answer: d

Explanation: Mechanical properties include strength, toughness, ductility, stiffness, hardness, and resistance to fatigue, creep, and impact.

7. The physical properties of good product material are

a) density

b) melting point

c) specific heat

d) all of the mentioned

Answer: d

Explanation: Physical properties include density, melting point, specific heat, thermal and electrical conductivity, thermal expansion, and magnetic properties.

8. The chemical properties of good product material are

a) oxidation

b) corrosion

c) surface treatment

d) all of the mentioned

Answer: d

Explanation: Chemical properties of primary concern in manufacturing are susceptibility to oxidation and corrosion and to the various surface-treatment processes.

9. Properties of workpiece materials are

a) geometric features of the part

b) production rate and quantity

c) process selection consideration

d) all of the mentioned

Answer: d

Explanation: None.

10. Considerations of costing systems are

a) life cycle costs

b) machine usage

c) cost of purchasing machinery

d) all of the mentioned

Answer: d

Explanation: Costing Systems, also called cost justification, typically include the following considerations:  intangible benefits of quality improvements and inventory reduction,  life-cycle costs,  machine usage,  cost of purchasing machinery compared with that of leasing it,  financial risks involved in implementing highly automated systems, and  new technologies and their impact on products.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Gear Basics-1”.

1. Thickness of tooth measured along the pitch circle is known as

a) Tooth thickness

b) Backlash

c) Face width

d) Top land

Answer: a

Explanation: Tooth thickness is the thickness of tooth measured along the pitch circle.

2. Difference between space width and to thickness of tooth along the pitch circle is known as

a) Tooth thickness

b) Backlash

c) Face width

d) Top land

Answer: b

Explanation: Backlash is the Difference between space width and to thickness of tooth along the pitch circle.

3. Length of tooth parallel to gear axis is known as

a) Tooth thickness

b) Backlash

c) Face width

d) Top land

Answer: c

Explanation: Face width is the length of tooth parallel to gear axis.

4. Top surface of tooth is known as

a) Tooth thickness

b) Backlash

c) Face width

d) Top land

Answer: d

Explanation: Top land is the top surface of tooth.

5. Bottom surface of the tooth between two adjacent fillets is known as

a) Flank

b) Face

c) Bottom Land

d) Fillet

Answer: c

Explanation: Bottom surface of the tooth between two adjacent fillets is known as bottom land.

6. Surface of tooth between pitch circle and top land is known as

a) Flank

b) Face

c) Bottom Land

d) Fillet

Answer: b

Explanation: Surface of tooth between pitch circle and top land is known as face.

7. Tooth surface between pitch circle and the bottom land including fillet is known as

a) Flank

b) Face

c) Bottom Land

d) Fillet

Answer: a

Explanation: Tooth surface between pitch circle and the bottom land including fillet is known as flan.

8. Curved portion of the tooth flank at the root circle is known as

a) Flank

b) Face

c) Bottom Land

d) Fillet

Answer: d

Explanation: Curved portion is called fillet.

9. Force exerted by driving tooth on the driven tooth along the line of pitch point to the point of contact of two teeth is known as

a) Line of Action

b) Path of contact

c) Arc of contact

d) Angle of action

Answer: a

Explanation: Force exerted by driving tooth on the driven tooth along the line of pitch point to the point of contact of two teeth is known as the line of action.

10. Angle between the pressure line and the common tangent to the pitch circle is known as

a) Pressure angle

b) Path of contact angle

c) Arc of contact angle

d) Angle of action

Answer: a

Explanation: Angle between the pressure line and the common tangent to the pitch circle is known as pressure angle.

11. Backlash of gear is given by

a) Space width – Tooth Thickness*2

b) Space width / Tooth Thickness

c) Space width – Tooth Thickness

d) Space width * Tooth Thickness

Answer: c

Explanation: Backlash = Space width – Tooth Thickness.

12. Ratio of speed of the follower to the speed of driving gear is known as

a) Gear ratio

b) Module

c) Velocity ratio

d) None of the mentioned

Answer: c

Explanation: Velocity ratio is the Ratio of speed of the follower to the speed of driving gear.

13. Ratio of diameter of driving gear to the diameter of follower is known as

a) Gear ratio

b) Module

c) Velocity ratio

d) None of the mentioned

Answer: c

Explanation: Velocity ratio is the ratio of diameter of driving gear to the diameter of follower.

14. Ratio of number of teeth on driving gear to the number of teeth on follower is known as

a) Gear ratio

b) Module

c) Velocity ratio

d) None of the mentioned

Answer: c

Explanation: Velocity ratio is the ratio of number of teeth on driving gear to the number of teeth on follower.

15. Angle subtended by circular pitch at the centre of pitch circle is known as

a) Pitch angle

b) Addendum angle

c) Module angle

d) None of the mentioned

Answer: a

Explanation: Pitch angle is the angle subtended by circular pitch at the centre of pitch circle.

This set of Manufacturing Science Question Bank focuses on “Gear Basics-2”

1. Which of the following is not a standard pressure angle in degree?

a) 20

b) 25

c) 14.5

d) 19

Answer: d

Explanation: 19 degree is not a standard pressure angle.

2. Distance between the points of contact of two mating teeth from the beginning of engagement to the end of engagement is known as

a) Arc of contact

b) Path of contact

c) Path of approach

d) Path of recess

Answer: b

Explanation: Path of contact is the distance between the points of contact of two mating teeth from the beginning of engagement to the end of engagement.

3. Path of contact from the beginning of engagement to the pitch point is known as

a) Arc of contact

b) Path of contact

c) Path of approach

d) Path of recess

Answer: c

Explanation: Path of approach is equal to path of contact from the beginning of the engagement to the pitch point.

4. Portion of path of contact from the pitch point to end of engagement is known as

a) Arc of contact

b) Path of contact

c) Path of approach

d) Path of recess

Answer: d

Explanation: Path of recess is the portion of path of contact from the pitch point to end of the engagement.

5. Circumferential distance between points from the beginning to the end of engagement of two mating gear on pitch circle is known as

a) Arc of contact

b) Path of contact

c) Path of approach

d) Path of recess

Answer: a

Explanation: Arc of contact is the circumferential distance between points from the beginning to the end of engagement of two mating gear on pitch circle.

6. Portion of arc of contact from the beginning of the engagement to the pitch point is known as

a) Contact ratio

b) Angle of friction

c) Arc of recess

d) Arc of approach

Answer: d

Explanation: Arc of approach is the portion of arc of contact from the beginning of the engagement to the pitch point.

7. Portion of arc of contact from the pitch point to the end of engagement is known as

a) Contact ratio

b) Angle of friction

c) Arc of recess

d) Arc of approach

Answer: c

Explanation: Arc of recess is the portion of arc of contact from the pitch point to the end of the engagement.

8. Angle subtended by arc of contact at the centre of pitch circle is known as

a) Contact ratio

b) Angle of action

c) Arc of recess

d) Arc of approach

Answer: b

Explanation: Angle of action is the angle subtended by arc of contact at the centre of pitch circle.

9. Number of teeth in contact is given by

a) Arc of contact

b) Path of contact

c) Contact ratio

d) Path of recess

Answer: c

Explanation: Contact ratio is the number of teeth in contact of two mating gear.

10. Contact ratio is given by

a) Angle of action/pitch angle

b) Angle of action*pitch angle

c) Angle of action-pitch angle

d) Angle of action +pitch angle

Answer: a

Explanation: Contact ratio = Angle of action/pitch angle.

11. Which of the following is a standard pressure angle in degree?

a) 20

b) 21

c) 13.5

d) 19

Answer: a

Explanation: 20 degree is a standard pressure angle.

12. Which of the following is a standard pressure angle in degree?

a) 24

b) 21

c) 14.5

d) 19

Answer: c

Explanation: 14.5 degree is a standard pressure angle.

13. Which of the following is a standard pressure angle in degree?

a) 25

b) 21

c) 13.5

d) 19

Answer: a

Explanation: 25 degree is a standard pressure angle.

14. Distance between the points of contact of two mating teeth from the beginning of engagement to the end of engagement is known as

a) Arc of contact

b) Contact length

c) Path of approach

d) Path of recess

Answer: b

Explanation: Path of contact is the distance between the points of contact of two mating teeth from the beginning of engagement to the end of an engagement. Path of contact is also known as contact length.

15. For a given pair of mating gear, angle of action is 19 degree and pitch angle is 4 degree. Contact ratio is equal to

a) 3.20

b) 2.13

c) 4.75

d) 6.32

Answer: c

Explanation: Contact ratio = Angle of action/pitch angle.

This set of Manufacturing Engineering Multiple Choice Questions & Answers  focuses on “Gear Terminology-1”.

1. Imaginary friction cylinders which by pure rolling together transmit the same motion as pair of gears is known as

a) Pitch cylinders

b) Pitch diameter

c) Pitch circle

d) Pitch point

Answer: a

Explanation: Imaginary friction cylinders which by pure rolling together transmit the same motion as pair of gears is known as pitch cylinders.

2. Circle which corresponds to section of equivalents cylinder by a plane normal to wheel axis is known as

a) Pitch cylinders

b) Pitch diameter

c) Pitch circle

d) Pitch point

Answer: c

Explanation: Pitch circle is the circle which corresponds to section of equivalents cylinder by a plane normal to wheel axis.

3. Diameter of pitch cylinder is known as

a) Pitch cylinders

b) Pitch diameter

c) Pitch circle

d) Pitch point

Answer: b

Explanation: Pitch diameter is the diameter of a pitch cylinder.

4. Two different pitch circles generally meet at

a) Pitch cylinders

b) Pitch diameter

c) Pitch circle

d) Pitch point

Answer: d

Explanation: At pitch point two different pitch circles generally meets.

5. Line passing through center of rotation of two meeting gear is known as

a) Pitch line

b) Rack

c) Pinion

d) Line of centre

Answer: d

Explanation: Line of centre is the line passing through center of rotation of two meeting gear.

6. Driving gear of two mating gear which is generally small is known as

a) Pitch line

b) Rack

c) Pinion

d) Line of centre

Answer: c

Explanation: Pinion is the driving gear of two mating gear which is generally small.

7. Gear wheel of infinite diameter is also known as

a) Pitch line

b) Rack

c) Pinion

d) Line of centre

Answer: b

Explanation: Rack have infinite diameter.

8. Part of pitch circle of rack which is a straight line is also known as

a) Pitch line

b) Rack

c) Pinion

d) Line of centre

Answer: a

Explanation: Pitch line is the part of pitch circle of rack which is a straight line.

9. Ratio of circumference of pitch circle to number of teeth is known as

a) Circular pitch

b) Diametral pitch

c) Module

d) Gear ratio

Answer: a

Explanation: Circular pitch is the ratio of a circumference of pitch circle to number of teeth.

10. Distance measured along the circumference of pitch circle from a point on tooth to the corresponding point on adjacent tooth is known as

a) Circular pitch

b) Diametral pitch

c) Module

d) Gear ratio

Answer: a

Explanation: Circular pitch is the ratio of a circumference of pitch circle to number of teeth.

11. Number of teeth divided by length of pitch circle diameter is known as

a) Circular pitch

b) Diametral pitch

c) Module

d) Gear ratio

Answer: b

Explanation: Diametral pitch is the number of teeth divided by length of pitch circle diameter.

12. Ratio of pitch diameter in mm to the number of teeth is known as

a) Circular pitch

b) Diametral pitch

c) Module

d) Gear ratio

Answer: c

Explanation: Module is the ratio of pitch diameter in mm to the number of teeth.

13. Module of two mating gears must be

a) Same

b) Different

c) Small

d) None of the mentioned

Answer: a

Explanation: Module of two mating gear must be same.

14. Ratio of number of teeth on gear to the number of teeth on pinion is known as

a) Circular pitch

b) Diametral pitch

c) Module

d) Gear ratio

Answer: d

Explanation: Gear ratio is the ratio of number of teeth on gear to the number of teeth on pinion.

15. Ratio of angular velocity of the follower to the angular velocity of driving gear is known as

a) Gear ratio

b) Module

c) Velocity ratio

d) None of the mentioned

Answer: c

Explanation: Velocity ratio is the ratio of angular velocity of the follower to the angular velocity of driving gear.

This set of Manufacturing Science Interview Questions and Answers focuses on “Gear Terminology-2”.

1. Circle passing through the top of the tips of teeth is known as

a) Addendum circle

b) Addendum

c) Dedendum

d) Dedendum circle

Answer: a

Explanation: Circle passing through the top of the tips of teeth is known as addendum circle.

2. Height of tooth above pitch circle is known as

a) Addendum circle

b) Addendum

c) Dedendum

d) Dedendum circle

Answer: b

Explanation: Addendum is the height of tooth above pitch circle.

3. Addendum of gear is generally taken equal to

a) 1 module

b) 2 module

c) 1.157 module

d) 0.157 module

Answer: a

Explanation: Addendum of gear is generally taken equal to 1 module.

4. Circle passing through root of teeth is known as

a) Addendum circle

b) Addendum

c) Dedendum

d) Dedendum circle

Answer: d

Explanation: Circle passing through the root of teeth is known as dedendum circle.

5. Circle passing through root of teeth is known as

a) Addendum circle

b) Addendum

c) Dedendum

d) Root circle

Answer: d

Explanation: Circle passing through the root of teeth is known as root circle.

6. Radial depth of tooth below pitch circle is known as

a) Addendum circle

b) Addendum

c) Dedendum

d) Dedendum circle

Answer: c

Explanation: Dedendum is the radial depth of tooth below pitch circle.

7. Standard value of dedendum is generally taken as

a) 1 module

b) 2 module

c) 1.157 module

d) 0.157 module

Answer: c

Explanation: Dedendum of gear is generally taken equal to 1.157 modules.

8. Radial difference between addendum and dedendum of tooth is known as

a) Clearance

b) Full depth of teeth

c) Working depth of teeth

d) Space width

Answer: a

Explanation: Clearance is the radial difference between addendum and dedendum of tooth.

9. Standard value of clearance is generally taken as

a) 1 module

b) 2 module

c) 1.157 module

d) 0.157 module

Answer: d

Explanation: Clearance of gear is generally taken equal to 0.157 modules.

10. Total radial depth of tooth space is known as

a) Clearance

b) Full depth of teeth

c) Working depth of teeth

d) Space width

Answer: b

Explanation: Total radial depth of tooth space is known as full depth of teeth.

11. Maximum depth to which tooth can penetrate into the tooth space of mating gear is known as

a) Clearance

b) Full depth of teeth

c) Working depth of teeth

d) Space width

Answer: c

Explanation: Maximum depth to which tooth can penetrate into the tooth space of mating gear is known as working depth of teeth.

12. Width of tooth space along the pitch circle is known as

a) Clearance

b) Full depth of teeth

c) Working depth of teeth

d) Space width

Answer: d

Explanation: Space width is the width of tooth space along the pitch circle.

13. Full depth of teeth is equal to

a) Addendum * dedendum

b) Addendum / dedendum

c) Addendum – dedendum

d) Addendum + dedendum

Answer: d

Explanation: Full depth is the sum of addendum and dedendum.

14. Working depth of two mating gear is numerically equal to

a) Sum of addendum of two gears

b) Difference of addendum of two gears

c) Difference of dedendum of two gears

d) Sum of dedendum of two gears

Answer: a

Explanation: Working depth of two mating gear is numerically equal to sum of the addendum of two gears.

15. For a given pair of mating gear, arc of contact is 6mm and a circular pitch is 4 mm. Contact ratio is equal to

a) 3.20

b) 1.50

c) 4.75

d) 6.32

Answer: b

Explanation: Contact ratio = arc of contact/circular pitch.