Automotive Engine Design Pune University MCQs

 This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “Internal Combustion Engine”.

1. What is an internal combustion engine?

a) An engine that absorbs power by burning air+ water in a closed chamber

b) An engine that generates power by burning air+ fuel in a closed chamber

c) An engine that generates power by burning air+ fuel in an open chamber

d) An engine that absorbs power by burning air+ water in an open chamber

Answer: b

Explanation: Internal combustion engines are the engine that generates power by burning air and fuel  in a closed chamber. Nothing can burn in the presence of water because water is a fire extinguisher.

2. What is the idling RPM of a motorcycle petrol engine?

a) 1200RPM

b) 700RPM

c) 18000RPM

d) 60RPM

Answer: a

Explanation: Idling RPM of a petrol engine is 1200 and for diesel engines, it is 700, whereas 18000 RPM is maximum RPM for superbike and 60 doesn’t exist.

3. Anything which burns in the presence of ______ is known as combustion.

a) water

b) fuel

c) air

d) salt

Answer: c

Explanation: Fuel always need oxygen to get combusted and the air is the only source for the availability of oxygen. Hence, anything which burns in the presence of air is known as combustion.

4. What was used as fuel during the early invention of IC engines?

a) Gun-powder

b) Petrol

c) Potassium

d) Kerosene

Answer: a

Explanation: In the 1600s, Gun powder was available as explosive, Huygen invented and engine that uses gunpowder as the fuel. Petrol and kerosene didn’t exist in those days and potassium is not used in the engine till today.

5. Otto cycle is used in which engine?

a) External combustion engine

b) Petrol engine

c) Diesel engine

d) Steam engine

Answer: b

Explanation: Otto cycle explains the working of a petrol engine for each stroke that takes place. The diesel engine uses a diesel cycle. The steam engine is a part of the external combustion engine and they don’t follow the Otto cycle.

6. Who invented the first car which used gasoline as fuel?

a) Rudolf Diesel

b) Nikola Tesla

c) Nikolaus Otto

d) Karl Benz

Answer: d

Explanation: Karl Benz invented the first car which used gasoline/petrol as fuel. Rudolf diesel discovered diesel and Nikolaus Otto discovered petrol engine. Nikola Tesla discovered AC.

7. How many power strokes are produced in a 4-stroke diesel engine running at 1500RPM?

a) 750

b)1500

c) 1000

d) 375

Answer: a

Explanation: In a 4-stroke engine the power stroke is produced in every two rotation of the crankshaft.

Number of power strokes=\(\frac{RPM}{number \, of \, crank \, rotation \, for \, one \, complete \, rotation \, of \, the \, flywheel}\) Hence, \(\frac{1500}{2}=750\)

8. Which of the mentioned below is not a component of the IC engine?

a) Piston

b) Cylinder

c) Wheel

d) Spark plug

Answer: c

Explanation: Piston, Cylinder, Spark plug are the components of the IC engine whereas the wheel absorbs the power from the IC engine and produces a tractive force that helps in moving the vehicle.

9. The black smoke coming out of a petrol engine is due to what particles?

a) Oxygen molecules

b) Magnesium particles

c) Nitrox

d) Carbon particles

Answer: d

Explanation: The black smoke is due to the presence of carbon particles which is formed because of incomplete combustion caused by less amount of air to the supplied fuel.

10. Which is the first company to use assembly line mode for the production of cars?

a) Fiat

b) Mercedes Benz

c) Ford

d) Volvo

Answer: c

Explanation: Henry ford in the year 1908 started the first mass production of car Model T using assembly line mode of production. Benz invented the first car. Fiat and Volvo emerged later on in the automotive industry.

11. Which of the mentioned below is the external combustion engine?

a) Wankel engine

b) Steam engine

c) Petrol engine

d) VTEC engine

Answer: b

Explanation: The Steam engine is an example of an external combustion engine that uses steam as the working fluid to produce energy. The steam is produced externally by burning coal.

12. Who invented the Compression ignition engine?

a) Issac Newton

b) Rudolf Diesel

c) Nikolaus August Otto

d) Albert Einstein

Answer: b

Explanation: The compression ignition engine is also known as the Diesel engine and it was invented by Rudolf diesel in the 1890s. Nikolaus August Otto invented the SI engine. Issac Newton defined forces and Albert Einstein worked in the field of space and light.

13. What is the compression ratio of the Diesel engine?

a) 15:1 to 23:1

b) 9:1 to 14:1

c) 1:15 to 1:23

d) 1:9 to 1:14

Answer: a

Explanation: The compression ignition has no spark plug to ignite the fuel. So, the charge is compressed to high pressure to self-ignite and the compression ratio ranges from 15:1 to 23:1.

14. The Wankel engine is also called a Rotary engine.

a) True

b) False

Answer: a

Explanation: The Wankel engine uses an eccentric rotary design to convert power to Rotary motion. Hence, the Wankel engine is also called a rotary engine.

15. What is the stoichiometric ratio of the Air + Gasoline mixture?

a) 14.5:1

b) 1:14.5

c) 14.7:1

d) 14.3:1

Answer: c

Explanation: The stoichiometric ratio of Air + Gasoline mixture is 14.7:1 which means 14.7 parts of air are required to burn 1 part of the fuel.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Cylinder and Cylinder Liner”.

1. What is the primary function of the cylinder in the engine?

a) To hold the crankshaft

b) To guide the camshaft

c) To guide the piston

d) To hold the valves

Answer: c

Explanation: The two primary functions of the cylinder is to act as the combustion chamber in the engine and to guide the piston movement. The crankshaft’s function is to transfer rotary motion.

2. What type of cooling system is used in an early single-cylinder engine with cooling fins around it?

a) Coolant cooled

b) Air-cooled

c) Oil cooled

d) Water-cooled

Answer: b

Explanation: The early single-cylinder engine has cooling fins around. The heat from the cylinder is passed through the surface of the fins and when it is exposed to a current of air the engine cools.

3. In modern engines, the cylinder is made of what material?

a) Cast iron

b) Tin

c) Steel

d) Aluminum

Answer: d

Explanation: Earlier Cast iron was used as the cylinder material, but due to its heavyweight, modern cars use Aluminum which resulted in better efficiency.

4. Why liners are used in the cylinder?

a) Having liner only with better-material can be more economical

b) Having liner results in low cost

c) Having liner only with better-material can be less economical

d) Having liner results in high cost

Answer: a

Explanation: By having cylinder liner only with better-material can be more economical instead of having all the material of the engine with a better grade of material.

5. Usually, Cylinder liner is made up of what material?

a) Tungsten

b) Cast iron alloy

c) Aluminum alloy

d) Mild steel

Answer: b

Explanation: Cast iron along with chromium or vanadium is used as the cylinder liner material because of its low thermal expansion and lubrication property.

6. Which of the mentioned below is a type of liner?

a) Cold liner

b) Hot liner

c) Dry liner

d) Cast iron liner

Answer: c

Explanation: There are two types of liners Dry liner and Wet liner, dry liners are the one which is not in direct contact with coolant. Wet liners are the one which has direct contact with the coolant.

7. A cylinder has clearance length is 0.3mm and cylinder diameter is 150mm, what is the clearance volume?

a) 45mm 3

b) 0.45mm 3

c) 0.55mm 3

d) 0.045mm 3

Answer: a

Explanation: Clearance volume = Clearance length × Cylinder diameter

=0.3 × 150

= 45mm 3

8. In the below-shown cross-section of the cylinder diagram, what is the portion name?

a) Coolant

b) Liner

c) Air filter

d) Water jacket

Answer: d

Explanation: The space shown in the diagram is called a Water jacket. Through water jackets, the water flows around the engine cylinder. Coolant is the anti-freezer added to stop the boiling of water. Liner is the one that is around the cylinder and the air filter is not related to the diagram.

9. Which of the following are the two types of Cylinder liners?

a) Cold and Hot liners

b) Mild and Soft liners

c) Dry and Wet liners

d) Tungsten and Titanium Liners

Answer: c

Explanation: The two types of cylinder liners are Dry and Wet liners. Dry liners are the one which is not in direct contact with that coolant and Wet liners have direct contact with the coolant

10. Which of the mentioned below is not the desired property of the cylinder and cylinder liner?

a) It should be corrosion resistant

b) It should not be wear-resistant

c) It should withstand thermal stresses

d) It should be strong enough to withstand high gas pressure

Answer: b

Explanation: Cylinder guides the piston moment, in case there is a loss in lubrication, the cylinder should not wear off. So, the cylinder and cylinder liner should be wear-resistant.

11. Why engine block has Cylinder for piston moment, why not cube or cuboidal?

a) The cylinder has good aesthetic

b) Stresses are equally distributed in the cylinder

c) Design rule

d) The cylinder doesn’t wear

Answer: b

Explanation: The joints in the cube or cuboidal tend to crack because the stresses are not equally distributed over the entire surface and also a lot of friction is produced between the piston and the guiding surface. But in the cylinder, the stresses are equally distributed.

12. In which type of cylinder liner cooling is more efficient?

a) Dry liner

b) Hot liner

c) Wet liner

d) Steel liner

Answer: c

Explanation: Wet liners have direct contact with the coolant, there is no separate material between cylinder liner and cylinder. Hence cooling is more efficient in Wet liner.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Bore and Length of Cylinder”.

1. Piston diameter can be considered as the cylinder bore diameter.

a) True

b) False

Answer: a

Explanation: Piston and Cylinder liner are held very close together such that the clearance between them can be neglected. So, the piston diameter can be considered as the cylinder bore diameter.

2. Where is Indicated power generated?

a) In the crankshaft

b) In the alternator

c) Inside the engine cylinder

d) In the Fuel pump

Answer: c

Explanation: Indicated power is obtained inside the engine cylinder, whereas brake power is obtained in the crankshaft, Alternator and fuel pump absorbs the brake power.

3. The tachometer is used to measure the Indicated power.

a) True

b) False

Answer: b

Explanation: First and foremost, indicated power can’t be measured practically using any device. Hence, Tachometer can’t be used to measure the indicated power.

4. In an engine running at 2200RPM has BP=35KW and FP=3KW, what is the value of IP?

a) 38KW

b) 38MW

c) 32KW

d) 32MW

Answer: a

Explanation: IP=BP+FP

IP=35KW+3KW

=38KW

5. An engine has a mechanical efficiency of 80% with an IP of 35KW, calculate BP.

a) 28MW

b) 2.8W

c) 2.8GW

d) 28KW

Answer: d

Explanation: η mechanical =\

 

=28KW

6. In the formula IP=\

 

 RPM of the engine

b) Number of working strokes

c) Area of cylinder

d) Pressure

Answer: b

Explanation: ‘n’ represents the number of working strokes, RPM is denoted by ‘N’, Area is denoted by ‘A’ and pressure is denoted by ‘P m ’.

7. What is the Standard unit of P m ?

a) N/m 3

b) N/mm 2

c) KN/mm 2

d) KN/m 3

Answer: b

Explanation: P m is called as mean effective pressure, the pressure is a force upon the unit area(N/mm 2 ). K is not a unit; it is a multiplier.

8. A 2-stroke engine has following specifications A=9852.3mm 2 , IP=4600, Pm=0.35Mpa, N=500RPM. Calculate the value of length.

a) 80mm

b) 80m

c) 0.8mm

d) 8m

Answer: a

Explanation: IP=\

 

/60

l=80mm

9. What is the standard unit of BP?

a) KW

b) W

c) MW

d) N/mm 2

Answer: b

Explanation: BP is called Brake Power and the standard unit of power is Watt represented by ‘W’. K and M are just Multipliers and N/mm 2 is the unit for pressure.

10. In the formula IP=\

 

 has to be considered?

a) mm

b) Km

c) m

d) µm

Answer: c

Explanation: Here length is always considered in meters as a standard, whereas diameter is taken in mm, during the early age of engines the stroke length was more when compared to bore diameter, µm gives value in 1000s and Km gives value in 0.0001, so the conventional unit meters.

11. Which of the below-mentioned test is used to find FP?

a) Calorimeter test

b) FIP test

c) Compression test

d) Morse test

Answer: d

Explanation: FP cannot be measured practically, by performing more test i.e., short-circuiting the spark plug or the fuel supply and by calculation, FP can be calculated theoretically.

12. What is Frictional Power?

a) It is the power loss due to friction

b) It is the power generated by friction

c) It is the power generated by crankshaft bearings

d) It is the friction generated due to power

Answer: a

Explanation: Engine is not 100% efficient, there is a power loss due to friction between the piston and the cylinder. Therefore, Frictional Power is the power loss due to friction.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “ IC Engine – Thickness of Cylinder Wall”.

1. Engine cylinder is considered to be ______

a) conical

b) thick cylinder

c) thin cylinder

d) rectangular

Answer: c

Explanation: Engine cylinder is considered to be a thin cylinder because the wall thickness is 1/20 times the internal diameter. Conical and Rectangular sections are not used because the stresses are not equally distributed.

2. What is a Reboring allowance?

a) It is the clearance between piston and cylinder

b) It is the additional metal thickness

c) It is the standard number to rebore

d) It is the allowance for the moment of the piston

Answer: b

Explanation: Reboring allowance is the additional metal thickness that is required to withstand maximum gas pressure. Also, when the cylinder wears out based on the availability of piston size the cylinder can be rebored.

3. Hoop stress is also known as ____________

a) circumferential stress

b) shear stress

c) shear strain

d) longitudinal stress

Answer: a

Explanation: Hoop stress is also known as Circumferential stress and it acts about the circumference of the cylinder. Hoop stress can also be called as tensile stress.

4. Find the allowable circumferential stress for the material having S ut =190 and the Factor of safety is 4.

a) 47.5 N/mm 2

b) 47.5N/m 2

c) 760N/mm 2

d) 760N/m 2

Answer: a

Explanation: σ t =\(\frac{S_{ut}}{F_s}\) = 190/4

=47.5N/mm 2

5. What is the thickness of the cylinder wall when the bore diameter is 150mm?

a) 8.35mm

b) 7.1mm

c) 8.8mm

d) 7.6mm

Answer: a

Explanation: t=0.045D+1.6

= 0.045×150+1.6

= 8.35mm

6. What is the range of thickness of the dry liner, when the bore diameter is 150mm?

a) 3.5 to 4.5mm

b) 4.5 to 5.25mm

c) 5.5 to 6mm

d) 6 to 7.2mm

Answer: b

Explanation: Thickness of dry liner ranges from 0.03D to 0.035D

=0.03×150 to 0.035×150

=4.5 to 5.25mm

7. What is the range of water jacket when the thickness is 8mm?

a) 2.6 to 6mm

b) 3.5 to 4mm

c) 4 to 5mm

d) 2.8 to 7mm

Answer: a

Explanation: Thickness of water jacket ranges from when the thickness is given is

=\(\frac{1}{3}t\) to \(\frac{3}{4}\)t

= 2.6 to 6mm

8. Calculate the range of thickness of the water jacket when D=160mm?

a) 4.1 to 5.1mm

b) 6.3 to 8mm

c) 5.12 to 1.6mm

d) 3.4 to 6mm

Answer: c

Explanation: Thickness of water jacket ranges from when bore diameter is given is

= 0.032D to 1.6

= 5.12 to 1.6mm

9. Calculate the water space between the outer cylinder wall and the inner jacket, bore is 160mm?

a) 18.4mm

b) 19.3mm

c) 20.2mm

d) 21.1mm

Answer: b

Explanation: Water space between the outer cylinder wall and the inner jacket is

=0.08D+6.5

=19.3mm

10. Find the range of thickness of cylinder flange when the thickness is 8mm.

a) 6.5 to 7.2mm

b) 7.5 to 8.8mm

c) 8.3 to 10.5mm

d) 9.6 to 11.2mm

Answer: d

Explanation: The range of thickness of the cylinder flange is

= 1.2t to 1.4t

= 9.6 to 11.2mm

11. Find the range of thickness of the cylinder flange when bolt diameter is 8mm.

a) 8 to 9.5mm

b) 9 to 10.6mm

c) 10 to 12mm

d) 11 to 13mm

Answer: c

Explanation: The range of Thickness of the cylinder flange is

=1.25d to 1.5d

=10 to 12mm

12. Find the range of radial distance between the outer diameter of the flange and pitch circle diameter of studs, when d is 8mm.

a) 14 to 12mm

b) 9 to 11mm

c) 10 to 14mm

d) 11 to 13mm

Answer: a

Explanation: The range of radial distance between the outer diameter of the flange and pitch circle diameter of studs is

= d+6 to 1.5d

= 14 to 12

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Stresses in Cylinder Wall”.

1. Longitudinal stress doesn’t act on the cylinder.

a) True

b) False

Answer: b

Explanation: Circumferential hoop stress and the longitudinal stress are the two principal stresses that act on the engine cylinder. So, longitudinal stress act on the cylinder.

2. Calculate the net circumferential stress when σ c =20N/mm 2 , σ I =11N/mm 2 and μ=0.2.

a) 17.8N/mm 2

b) 16.5N/mm 2

c) 16.5N/m 2

d) 16.3N/mm 3

Answer: a

Explanation: (σ c ) net =σ c -μσ I

=20-0.2×11

=17.8N/mm 2

3. Calculate the net longitudinal stress σ c =20N/mm 2 , σ I =11N/mm 2 and μ=0.2

a) 6N/mm 2

b) 7N/mm 2

c) 8N/mm 2

d) 9N/mm 2

Answer: a

Explanation: (σ I ) net =σ I -μσ c

=11-0.2×20

=7N/mm 2

4. Calculate the net minimum outer diameter of the cylinder, when the inner diameter of the cylinder is 140mm and thickness is 11mm.

a) 153mm

b) 170mm

c) 160mm

d) 162mm

Answer: d

Explanation: D 0 =D+2t

=140+2

=162mm

5. Calculate the thickness of the cylinder when P max =3MPa, D=150mm, C=4and σ c =45N/mm 2 .

a) 9mm

b) 6mm

c) 7mm

d) 8mm

Answer: a

Explanation: t=\(\frac{P_{max}\times D}{2\sigma}\)+C

=\(\frac{3×150}{2×45}+4\)

=5+4

=9mm

6. Calculate the apparent circumferential stress, when P max =3.5MPa, D=140mm, and t=8mm?

a) 12.3N/mm 2

b) 14.4N/mm 2

c) 15.3N/mm 2

d) 16.1N/mm 2

Answer: c

Explanation: σ c=\(\frac{P_{max}D}{2t}\)

=\(\frac{3.5×140}{2×16}\)

=15.3N/mm 2

7. Calculate the apparent longitudinal stress when Do=162mm, D=140mm, Pmax=3MPa.

a) 8.85N/mm 2

b) 9.32N/mm 2

c) 6.66N/mm 2

d) 7.65N/mm 2

Answer: a

Explanation: σ I =\(\frac{P_{max}D^2}{Do^2-D^2}\)

=\(\frac{3×140^2}{

}\)

=8.85N/mm 2

8. In the formula (σ I ) net =σ I -μσ c , what is µ?

a) Yield point

b) Hoop constant

c) Stress constant

d) Poisson’s ratio

Answer: d

Explanation: μ is Poisson’s ratio, it is the ratio of transverse contraction strain to the longitudinal extension strain. σ I is the longitudinal stress and σ c is the circumferential stress.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Cylinder Head”.

1. Find the Thickness of the cylinder head when D=140mm, K=0.162, P max =3.5Mpa, σ c =30N/mm 2 .

a) 17.56mm 2

b) 19.34mm

c) 18.52mm 2

d) 19.24mm

Answer: d

Explanation:t h =140×\(\sqrt\frac{0.162×3.5}{30}\)

= 140×0.1374

= 19.24mm

2. It is mandatory to have cams in the cylinder head.

a) True

b) False

Answer: b

Explanation: No, it is not mandatory to have a camshaft in the cylinder head. There are instances where the camshaft is placed near the crankshaft and the valve actuation is controlled by pushrod and tappets.

3. Which of the mentioned below is not a part of the Cylinder head?

a) Valves

b) Spark plug

c) Cams

d) Crankshaft

Answer: d

Explanation: Valves, Spark plug, Cams are all housed in the cylinder head whereas the crankshaft is housed in the crankcase and drives the camshaft.

4. What is porting?

a) Drilling extra ports in the cylinder

b) Resizing and reshaping of the intake port

c) Resizing and reshaping for spark plug

d) Drilling additional port for spark plug

Answer: b

Explanation: Porting is the application of resizing and reshaping of intake ports so that the charge doesn’t strike the wall and ensuring the flow of charge is smooth.

5. Which material is suitable for manufacturing Cylinder head?

a) Malleable

b) Cast iron

c) Mild steel

d) Carbon fiber

Answer: b

Explanation: Cast iron is a brittle material and it is used in the manufacturing of Cylinder head and also aluminum can be used since it is lightweight.

6. The charge is compressed directly against which part of the engine?

a) Crankcase

b) Cylinder

c) Camshaft

d) Cylinder head

Answer: d

Explanation: After the suction stroke, during the moment of the piston for BDC to TDC the charge is compressed against the cylinder head and then it gets ignited.

7. Which of the mentioned below is not a type of cylinder head?

a) Under head camshaft cylinder head

b) Overhead camshaft cylinder head

c) Flathead cylinder head

d) Overhead valve cylinder head

Answer: a

Explanation: Overhead camshaft cylinder head, Flathead cylinder head, Overhead valve cylinder head are the three types of cylinder heads and they are made of cast-iron or aluminum.

This set of Automotive Engine Components Design Interview Questions and Answers focuses on “IC Engine – Design of Studs for Cylinder Head”.

1. An engine has a bore diameter of 160mm, what is the maximum number of studs in the engine?

a) 6

b) 7

c) 8

d) 9

Answer: c

Explanation: Maximum number of studs = 0.02D+4

= 0.02×160+4

= 7.2

7.2 studs can’t be taken so it is approximated to 8.

2. An engine has a bore diameter of 150mm, what is the minimum number of studs in the engine?

a) 6

b) 7

c) 8

d) 9

Answer: a

Explanation: Maximum number of studs = 0.01D+4

= 0.01×150+4

= 5.5

5.5 studs can’t be taken so it is approximated to 6.

3. Why studs are used?

a) To ensure the proper fixture of the crankshaft

b) To ensure the proper fixture of connecting rod

c) To ensure the proper fixture of the camshaft

d) To ensure the proper fixture of the cylinder assembly

Answer: d

Explanation: Studs act as the guide ways to the cylinder assembly to reduce the distortion of the planned geometry. The crankshaft is placed below the cylinder. Camshaft placed in the cylinder head and Connecting rod is fixed between piston and crankshaft.

4. ‘Y’ is the notation used usually to denote the number of studs.

a) True

b) False

Answer: b

Explanation: ‘Z’ is the notation used usually to denote the number of studs. These are the circular rods threaded over both sides and connect various engine components.

5. Which of the mentioned below is not the parameter in the design of studs?

a) Nominal diameter of Gudgeon pin

b) Nominal diameter of the cylinder

c) Number of studs

d) Pitch of studs

Answer: a

Explanation: Nominal diameter of the cylinder, Number of studs, Pitch of studs are all the required parameters for the design of studs whereas the Nominal diameter of the Gudgeon pin is used in the design of piston.

6. Which of the following material is used in the manufacturing of studs?

a) Iron

b) Nickel

c) Steel

d) Titanium

Answer: c

Explanation: Ductile is the type of material used in the manufacturing of studs since it has good thermal conductivity, yield strength, and tensile strength. Steel is one of the ductile materials.

7. What is the nominal diameter of studs when the core diameter of studs is 1.5mm?

a) 1.8m

b) 2.5mm

c) 1.8mm

d) 2.5m

Answer: c

Explanation: The nominal diameter of studs when the core diameter of studs is given,

d=\(\frac{d_c}{0.8}\)

d=\(\frac{1.5}{0.8}\)

d=1.87mm

8. What is the pitch of studs, when the diameter of studs is 6mm and the number of studs is 8?

a) 2.35mm

b) 1.80mm

c) 7.00mm

d) 4.95mm

Answer: a

Explanation: Pitch of stud s=\(\frac{\pi \times D_p}{Z}\)

=\(\frac{\pi\times 6}{8}\)

=2.35mm

9. Find the pitch circle diameter of studs, given D=6 and d=4?

a) 16mm

b) 17mm

c) 18mm

d) 19mm

Answer: c

Explanation: Pitch circle diameter of studs is given by,

D p =D+3d

=6+3×4

=18mm

10. Find the minimum pitch value of studs when d=1.5mm?

a) 23.27mm

b) 0.23mm

c) 2.32mm

d) 4.43mm

Answer: a

Explanation: Minimum pitch=\(19\sqrt{d}\) =23.27mm

11. Find the maximum pitch value of studs when d=1.5mm?

a) 15.78mm

b) 43.9mm

c) 14.87mm

d) 34.90mm

Answer: d

Explanation: Maximum pitch=28.5\(\sqrt{d}\) =28.5\(\sqrt{1.5}\)

=34.90mm

12. Studs experience fluctuating load.

a) True

b) False

Answer: a

Explanation: Due to the combustion of fuel, the variation in gas pressure inside the engine cylinder changes from 0 to P max . Hence, studs experience fluctuating load.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston”.

1. Piston is a______ part of IC engine.

a) Rotating

b) Revolting

c) Reciprocating

d) Oscillating

Answer: c

Explanation: The piston is a reciprocating part of the IC engine that performs several functions. It seals the inside portion of the cylinder from the crankcase using a piston ring.

2. Which force is the reason for the downward moment of the piston during power stroke?

a) Fuel pressure

b) Gas pressure

c) Solid pressure

d) Liquid pressure

Answer: b

Explanation: Pistons transmit the force due to gas pressure inside the cylinder to the crankshaft through the connecting rod. The gas pressure is created by the combustion inside the engine.

3. Gas is compressed during which the stroke of the engine?

a) Suction stroke

b) Compression stroke

c) Power stroke

d) Exhaust stroke

Answer: b

Explanation: The Piston compresses the gas during the compression Stroke. It takes the side thrust resulting from the obliquity of the connecting rod. Due to compression, the temperature of the charge increases.

4. Why the length of piston in the 2-stroke engine is more when compared to the 4-stroke engine?

a) Absence of valve mechanism

b) Missing of Power stroke

c) It is not 4-stroke

d) Air resistance

Answer: a

Explanation: Due to the absence of a valve mechanism, the intake and exhaust of the 2-stroke engine have to be controlled by the piston itself. Hence, the length of the piston in a 2-stroke engine is more when compared to the 4-stroke engine.

5. What is that convex part on the piston on a 2-stroke engine is known as?

a) Kingpin

b) Deflector

c) Concave

d) Vector

Answer: b

Explanation: The convex part on the piston on a 2-stroke engine is known as a deflector. This deflector helps in scavenging, this diverts the exhaust gas to move towards the exhaust port.

6. Which of the mentioned below is not a part of the piston?

a) Shim

b) Circlip

c) Gudgeon pin

d) Oil ring

Answer: a

Explanation: Circlip, Gudgeon pin, and oil ring are all the part of the piston. Whereas, Shim is a component related to the valve mechanism, using this Valve lift can be altered.

7. Using which component Piston and connecting rod are connected?

a) Circlip

b) Gudgeon pin

c) Cotter

d) Key

Answer: b

Explanation: The piston and connecting rod are connected through the Gudgeon pin. It is also called a piston pin and wrist pin. The end movement of the gudgeon pin is stopped by a circlip.

8. Which part of the piston experience High thermal stress?

a) Head

b) Skirt

c) Top land

d) Rib

Answer: a

Explanation: Head is the topmost part of the piston. It is the first part to experience the heat due to combustion and experience high thermal stresses. It is also called a piston crown.

9. Piston should result in noiseless operation.

a) True

b) False

Answer: a

Explanation: Piston should always result in noiseless operation. If there is a noise, it indicates that there is a friction created due to an error in the design. The drops the efficiency of the engine.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston Materials”.

1. Which of the following material is not used in the manufacturing of pistons?

a) Steel

b) Aluminum alloy

c) Cast iron

d) Mild steel

Answer: d

Explanation: Steel, Aluminum alloy and Cast iron are the materials used in the pistons based on there thermal capacity, density factor, and lubrication property. Whereas mild steel is a ductile material and it is not used in pistons.

2. Which property of the aluminum alloy is preferred in pistons?

a) Color

b) Density factor

c) Thermal property

d) Aesthetics

Answer: b

Explanation: The Density factor of aluminum alloy is \(\frac{1}{3}\)rd to that of cast iron, this results in lightweight construction and reduces inertia force, make piston moment easier.

3. Which is the preferred process used in the manufacturing of pistons?

a) Forging

b) Casting

c) Forming

d) Machining

Answer: a

Explanation: Pistons manufactured using the Forging process because this process is more reliable and stronger than casting and can withstand high thermal stresses.

4. Earlier, which material was used in pistons?

a) Aluminum alloy

b) Cast iron

c) Steel

d) Brass

Answer: b

Explanation: Earlier, cast iron was widely used as it has higher strength compared to aluminum alloy. This helps to provide thin and small sections for the parts of cast iron piston.

5. Why aluminum alloy pistons are used in highly rated engine?

a) Due to its thermal factor

b) Due to its alloying element

c) Due to the piston speed

d) Due to circular

Answer: c

Explanation: Highly rated engines are mostly used in race cars and high-end cars; these cars require speed. Aluminum pistons can achieve piston speed above 6m/s. Hence, aluminum alloy pistons are used in a highly rated engine.

6. Cast iron pistons were used in low-speed cars, why?

a) Due to inertia force

b) Due to low-speed piston

c) Due to momentum

d) Due to centrifugal force

Answer: b

Explanation: Cast iron pistons were used in low-speed cars because its piston speed is always less than 6 m/s, this speed was due to the density of piston.

7. Why aluminum alloy pistons need more clearance?

a) Free moment

b) Good fixture

c) Thermal expansion

d) Cold start

Answer: c

Explanation: The coefficient of thermal expansion of the aluminum piston is approximately twice that of cast iron piston. Hence, Aluminum alloy pistons need more clearance.

8. Why cast iron was used in pistons earlier?

a) Availability

b) Cost

c) Luster property

d) Design feature

Answer: a

Explanation: Availability of cast iron was more when compared to steel, aluminum alloy, etc…, People found the manufacturing process using cast iron was easy until density came into the picture.

This set of Automotive Engine Components Design Objective Questions & Answers focuses on “IC Engine – Thickness of Piston Head”.

1. Which are the two types of piston head?

a) Cup and flat type

b) Cup and cone type

c) Cone and bowl type

d) Flat and bowl type

Answer: a

Explanation: There are two types of piston heads- Flat and Cup type, Cup type is concave in cross-section and flat type has a straight surface in cross-section.

2. Piston thickness depends on what criteria?

a) Volume for combustion

b) Gas pressure

c) Aesthetic

d) Products of combustion

Answer: a

Explanation: The selection of the type of piston head depends on two criteria Volume of combustion and the arrangement of valves. Therefore, Volume for combustion is the right answer.

3. Which are the two criteria for calculating the thickness of the piston head?

a) Heat and Strain

b) Strain and stress

c) Fracture and Strength

d) Strength and Heat dissipation

Answer: d

Explanation: A lot of stresses are induced during combustion and it should be able to withstand the heat. Hence, Piston thickness can be calculated based on Strength and Heat dissipation.

4. Which of the mentioned below is the Grashoff’s formula?

a) t h =D\

 

 

 t h =D\

 

 

 t h =D\

 

 

 t h =D\(\sqrt{\frac{3}{16}\frac{P_{max}}{IP}}\)

Answer: b

Explanation: According to Grashoff’s law formula, the thickness of the piston head is given by, t h =D\(\sqrt{\frac{3}{16}\frac{P_{max}}{\sigma_b}}\) Where D is the bore diameter, P max is maximum gas pressure and σ b is the stress on the cylinder head.

5. Which of the mentioned below is the Held and favary for the thickness of the piston head?

a) t h =0.032D+1.5

b) t h =0.032D+1.5d

c) t h =0.032D+1.5h

d) t h =0.032V+1.5D

Answer: a

Explanation: Held and Favary suggested an empirical formula for finding the thickness of the piston head and it is given by t h =0.032D+1.5, where D is bore diameter.

6. Which of the mentioned below is used to calculate the thickness of the piston head based on heat dissipation?

a) t h =\(\frac{T}{12.56K

}\) × 10 3

b) H=\(\frac{H}{12.56K

}\) × 10 3

c) t h =\(\frac{H}{12.56K

}\) × 10 3

d) t h =\(\frac{m}{12.56K

}\) × 10 3

Answer: c

Explanation: t h is the thickness of the piston head, H is the Heat conducted, K is thermal conductivity factor, T c -T e is the temperature from the center to edge of the piston. When all these are summed, we get t h =\(\frac{H}{12.56K

}\times 10^3\).

7. Bore diameter is 150mm, calculate the thickness based on Held and favary formula?

a) 6.3mm

b) 5.7mm

c) 6.3mm 2

d) 5.7mm 2

Answer: a

Explanation: t h =0.032D+1.5

=0.032+1.5

=6.3mm

8. Calculate the amount of heat conducted through piston head, when C=0.05, HCV=47×10 3 KJ/Kg, m=0.25 Kg/Kw/s, BP=8W?

a) 4500KJ

b) 450KJ

c) 470KJ

d) 4700KJ

Answer: d

Explanation: H=[C×HCV×m×BP] ×10 3

=[0.05×47×10 3 ×0.25×8] ×10 3

= 4700KJ

9. Calculate the thickness of the piston head based on head dissipation, given H=5398.82, k=46.8, (T c -T e )=200?

a) 45.92mm

b) 30.85mm

c) 43.3mm

d) 35.98mm

Answer: a

Explanation: t h =\(\frac{H}{12.56K

}\) × 10 3

=\(\frac{5398.82}{12.56×46.8}\) × 10 3

= 45.92mm

10. Calculate the thickness of the piston head by strength criteria, given D=250mm, P max =3MPa, σ b = 43N/mm 2 .

a) 23.92mm

b) 32.85mm

c) 43.3mm

d) 28.593mm

Answer: d

Explanation: t h =D\(\sqrt{\frac{3}{16}\frac{P_{max}}{\sigma_b}}\)

=250\(\sqrt{\frac{3}{16}\frac{3}{43}}\)

= 28.593mm

Answer: c

Explanation: Here D is the bore diameter, P max is the maximum gas pressure and σ b is the stress on the piston. Stress is always forced upon unit area hence N/mm 2 .

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston Ribs and Cups”.

1. Why piston ribs are provided in the piston?

a) To strengthen cylinder

b) To strengthen piston head

c) To strengthen cams

d) To strengthen crankshaft

Answer: b

Explanation: Ribs strengthen the piston head against the gas pressure. They increase the rigidity and prevent the distortion of the piston head.

2. Ribs transmit heat from ______ to piston rings.

a) piston head

b) skirt portion

c) rings

d) piston pin

Answer: a

Explanation: Ribs transmit a large portion of combustion heat from the piston head to the piston rings. This reduces the temperature difference between the center and side of the piston head.

3. The side thrust is created by which component of the engine?

a) Camshaft

b) Crankshaft

c) Connecting rod

d) Wrist pin

Answer: c

Explanation: The side thrust is created by the obliquity of the connecting rod and it is transmitted to the piston at piston pin. Hence, connecting rod is the right answer.

4. The side thrust is transmitted to the cylinder wall through which portion of the piston?

a) piston head

b) skirt portion

c) rings

d) piston pin

Answer: b

Explanation: The side thrust is due to the ovality of the piston, due to the gas pressure on the piston head side thrust is created and it is transmitted to the cylinder wall through the skirt portion.

5. Find the range of thickness of the ribs when the thickness of the piston head is 8mm?

a) 2 to 4mm

b) 3.5 to 4.5mm

c) 2.6 to 4mm

d) 3.6 to 4mm

Answer: c

Explanation: Thickness of ribs is given by t r =\(\frac{t_h}{3}to\frac{t_h}{2}\)

=\(\frac{8}{3}to\frac{8}{3}\)

= 2.6 to 4mm

6. Find the radius of the cup, when the bore diameter is 150mm?

a) 100mm

b) 110mm

c) 115mm

d) 105mm

Answer: d

Explanation: Radius of cup= 0.7D

= 0.7×150

= 105mm

7. The additional space provided on the piston head is also known as______

a) cup

b) cone

c) cube

d) sphere

Answer: a

Explanation: The additional space provided on the piston head is known as a cup. The space for the cup on the piston head is decided based on the volume of combustion.

8. When the thickness of the piston head is 5mm, the thickness of the ribs is 1.6 to 2.5mm.

a) True

b) False

Answer: b

Explanation: When the thickness of the piston head is less than 6mm, ribs are not required hence the answer, thickness of ribs 1.6 to 2.5mm is wrong.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Engine Components – Piston Rings”.

1. Which among the following is not a function of the piston rings?

a) To seal the high-pressure gases

b) Easy passage for the heat to flow from crown to cylinder

c) Maintain sufficient lubrication

d) Helps in detonation

Answer: b

Explanation: The piston ring should seal for the high-pressure gases from the combustion chamber, should provide easy passage for heat flow from the piston to the crown,should maintain sufficient lubricating oil on cylinder walls throughout and should not help is detonation.

2. Which of the following is provided to make up for the cylinder wear?

a) Ring expander

b) Temperature sensor

c) Pressure relief valve

d) Crankcase ventilation

Answer: a

Explanation: The primary purpose of a ring expander it to make up for the cylinder wear which happens after some time. This cylinder wear has to avoided or else it may lead to many wear like scuffing, rapid wear, and ring breakage as well.

3. Which among the following is defined as percentage gap collapse when the ring closed to nominal cylinder diameter for 6 hrs at 350 degrees centigrade?

a) Thermal set

b) Pulse width

c) Base pulse width

d) Enthalpy

Answer: a

Explanation: The thermal set is defined ad the percentage gap collapses when the ring closed to nominal cylinder diameter for 6 hours at 350 degrees centigrade. The value thermal set for U1 is 12.5 it depends on the material used and the method used for casting.

4. Which of the following is not a factor for scuffing?

a) Proper protecting lubrication film

b) Overheated engine

c) Insufficient clearance

d) Lack of lubrication

Answer: a

Explanation: The main cause for scuffing is overheatedengine, lack of lubrication, insufficient clearance. An overheated engine wherein there is no proper cooling system and leakage of coolant. When a protective lubricating oil film is provided no scuffing takes place.

5. Which among the following type of piston ring is used for worn-out cylinders?

a) Delay action scraper ring

b) Composite rail scraper ring

c) Multi-piece oil control ring

d) Carbo glide ring

Answer: b

Explanation: The composite rail scraper ring is highly useful for worn-out cylinders having ovality or taper in the bores. Several steel rails are chrome plated and have rounded ends provide a smooth scraping action reducing wear of cylinder wall.

6. Which of the is caused due to excess of end gap?

a) Blow by and rapid wear

b) Scuffing and rapid wear

c) only rapid wear

d) Both blow bye and scuffing

Answer: d

Explanation: The amount of end gap has to be determined cautiously. Excessive end gap would result in blow-by and scuffing of the ring. On the other hand,the lesser the clearance would cause the ring ends to butt at high temperature resulting in non-uniform pressure.

7. Which of the following is not an advantage of reducing the ring width?

a) Machining the narrow grooves

b) Better resistance to ring scuffing

c) better resistance to ring flutter

d) Ring inertia are reduced

Answer: a

Explanation: The advantages of having a reduced ring width are better resistance to scuffing, better resistance to ring flutter, problems on ring inertia are reduced, lower piston height, and consequently lower engine height and the disadvantage is machining the narrow grooves I’m the piston accurately is quite difficult.

8. What is the range in millimeter of the end gap for the top compression ring per 25mm of bore size?

a) 0.01-0.04

b) 0.04-0.07

c) 0.07-0.12

d) 0.12-0.15

Answer: c

Explanation: The end gap for the top compression ring is controlled from 0.07 to 0.12 millimeters per 25 mm of bore size. The second end gap should be 0.12-0.25mm wider than the top ring gap to prevent the gas buildup.

9. Which of the following type of piston ring end gap is shown below?

a) Seal cut

b) Butt

c) Tapered

d) Gapless

Answer: b

Explanation: The ring end gaps may be either straight butt type or tapered or seal cut type. The above figure is a tapered type of piston ring. Whereas the tapered and the seal-cut type are more effective in preventing leakage, but are more costly.

10. What is the reduction of gas leakage in a gapless type ring?

a) 40-50

b) 10-20

c) 50-60

d) Has no effect

Answer: b

Explanation: Total seal of USA manufactures a gapless rings which though costlier, is claimed to reduce gas leakage by 10 to 20 percent when compared to a conventional ring. The ring gaps are different types depending on their cheapness.

11. Which are the other materials added to cast iron in the manufacturing of piston ring?

a) Aluminum and phosphorus

b) Silicon and aluminum

c) Silicon and manganese

d) Cadmium and phosphorus

Answer: c

Explanation: The material that is generally used for the piston ring is fine-grained alloy cast iron containing silicon and manganese. It has good heat and wear-resisting qualities. There are two types of iron alloy in use they are gray cast iron and ductile iron.

12. What is the minimum number of compression rings required in an engine?

a) 5

b) 1

c) 2

d) 3

Answer: c

Explanation: A minimum of two compression rings are required because of the high-pressure difference between the combustion chamber and the crankcase at the beginning of the power stroke. This difference may be as high as 70 atmospheres.

13. Which of the following is not a factor for ring selection?

a) Scavenging ratio

b) Dimensions of engine block

c) Piston design

d) Piston displacement

Answer: a

Explanation: The various factors necessary to select a ring for an engine are dimensions of the engine block, piston design, piston displacement, piston speed, bore to stroke ratio, cooling capacity, crankcase pressure whereas scavenging ratio has no main role in piston ring selection.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston Barrel”.

1. Where can we see the piston barrel in the piston?

a) Above the piston head

b) Below piston ring

c) Below the wrist pin

d) Below the piston head

Answer: d

Explanation: Piston barrel is the cylindrical portion of the piston below the piston head. It is the inner cavity below the piston head to the open end of the piston.

2. Which of the mentioned below is the formula for calculating the thickness of the piston barrel at the top end?

a) t 4 =

b) t 4 =0.03D+b+6.9)

c) t 3 =

d) t 3 =0.03D+t 4 +4.9)

Answer: c

Explanation: The thickness of the piston barrel at the top end is given by t 3 = where D is the piston diameter and b is the radial width of the ring.

3. In the formula t 3 = what is the unit of b?

a) m

b) μm

c) mm

d) mm 2

Answer: c

Explanation: This is the formula of the thickness of the piston barrel at the top end, where D is the piston diameter and b is the radial width of the ring. Since it is width so the standard is mm.

4. Calculate the thickness of the piston barrel at the top end, when D=80mm and b=7.5mm?

a) 14.8mm

b) 15.6mm

c) 13.7mm

d) 16.6mm

Answer: a

Explanation: t 3 =

= 

= 14.8mm

5. Calculate the thickness of the piston barrel at the lower end when t 3 =13mm?

a) 4.5 to 5mm

b) 3.25 to 4.55mm

c) 5.6 to 7mm

d) 2.25 to 4.6mm

Answer: b

Explanation: t 4 = (0.25t 3 to 0.35t 3 )

=  to 

= 3.25 to 4.55mm

6. Which type of piston rings are preferred in an engine?

a) Oversized rings

b) Undersized rings

c) Thin rings

d) Thick rings

Answer: c

Explanation: Thin rings reduce the frictional losses and wear of the surface. Several thin rings have better sealing action than a few thick rings.

7. What is the gap between the free ends of the ring before assembly when b=6mm?

a) 21 to 24mm

b) 20 to 23mm

c) 22 to 23mm

d) 21 to 25mm

Answer: a

Explanation: G=3.5b to 4b

= 3.5×6 to 4×6

= 21 to 24mm

8. What is the gap between the free ends of the ring after assembly when D=80mm?

a) 0.7 to 0.43mm

b) 0.11 to 0.25mm

c) 0.1 to 1.9mm

d) 0.16 to 0.32mm

Answer: d

Explanation: G=0.002D to 0.004D

= 0.002×80 to 0.004×80

= 0.16 to 0.32mm

9. Calculate the distance from the top of the piston to the first ring grove when t h =7mm?

a) 8.5 to 10mm

b) 7.5 to 9mm

c) 7 to 8.4mm

d) 8 to 9.4mm

Answer: c

Explanation: h 1 =t h to 1.2t h

= 7 to 1.2×7

= 7 to 8.4mm

10. Calculate the width of the ring groove when h=5mm?

a) 3 to 5.8mm

b) 3.75 to 5mm

c) 4 to 5.9mm

d) 4.7 to 5.2mm

Answer: b

Explanation: h 2 =0.75h to h

=0.75×5 to 5

= 3.75 to 5mm

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston Skirt”.

1. Which portion of the piston is known as a skirt?

a) The portion above compression rings

b) The portion between compression and oil rings

c) The portion above the oil rings

d) The portion below oil rings

Answer: d

Explanation: Skirt is the cylindrical portion in the piston between the last oil scraper ring and the open end of the piston. Hence, Portion below oil rings is the correct answer.

2. Maximum side thrust is experienced during which stroke?

a) Intake stroke

b) Exhaust stroke

c) Expansion stroke

d) Suction stroke

Answer: c

Explanation: Side thrust is due to the sudden load on the piston and this is experienced during the downward moment of the piston i.e., during the expansion stroke.

3. Which of the mentioned below is the formula for calculating side thrust considering coefficient of friction?

a) Side thrust=P b D

b) Side thrust=P b DL s

c) Side thrust=μ\

 

\)P max

d) Side thrust=\

 

\)P max

Answer: c

Explanation: In the formula, we should concentrate on the Co-efficient of friction and it is present in the formula of Side thrust=μ\

 

P\)P max .

4. Which of the mentioned below is the formula for calculating side thrust considering stroke length?

a) Side thrust=P b DL s

b) Side thrust=P b D

c) Side thrust=μ\

 

\)P max

d) Side thrust=μ\

 

\)

Answer: a

Explanation: In the formula, we should concentrate on stroke length l s and the stroke length is present in the formula of Side thrust= P b DL s .

5. In the formula Side thrust=μ\

 

\)P max what is the unit of P max ?

a) N

b) N/mm 2

c) N/m

d) N/mm

Answer: b

Explanation: In this formula of side thrust, µ is the coefficient of friction, D is the bore diameter and P max is the maximum bearing pressure and unit of pressure is always N/mm 2 .

6. In the formula Side thrust=P b DL s what is the unit of l s ?

a) Cm

b) Km

c) mm

d) m

Answer: c

Explanation: In this formula for side thrust P b is the allowable bearing pressure, D is the diameter whereas l s is the stroke length and it is always taken in mm.

7. Calculate the side thrust when μ=0.1, D=85mm and P max =4N/mm 2 ?

a) 2269.8N/mm 2

b) 100N/mm 2

c) 3264N/mm 2

d) 4563.4N/mm 2

Answer: a

Explanation: Side thrust=μ\

 

P_{max}\)

=0.1×\

 

\times 4\)

= 2269.8N/mm 2

8. Calculate the stroke length when side thrust is 19634.95N/mm 2 , P b =0.4N/mm 2 and D=250mm?

a) 180.4mm

b) 143.4mm

c) 180.9mm

d) 196.3mm

Answer: d

Explanation: Side thrust= P b DL s

19634=0.4×250×L s

L s =196.3mm

9. Calculate the empirical relationship for the length of the skirt when D=80mm?

a) 20 to 40mm

b) 35 to 70mm

c) 52 to 64mm

d) 43 to 57mm

Answer: c

Explanation: l s =  to 

=0.65×80 to 0.8×80

= 52 to 64mm

10. Calculate the empirical relationship for the length of the piston when D=80mm?

a) 60 t0 90mm

b) 80 to 120mm

c) 70 to 100mm

d) 90 to 110mm

Answer: b

Explanation: L= D to 1.5D

= 80 to 1.5×80

= 80 to 120mm

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Piston Pin”.

1. What is the function of the piston pin?

a) To connect the piston to the crankshaft

b) To connect the piston to the piston head

c) To connect cam to the piston

d) To connect the piston to the connecting rod

Answer: d

Explanation: The major function of the piston pin is to connect the piston to the connecting rod. The piston pin is also called a gudgeon pin or wrist pin.

2. Piston pin is having which cross-section?

a) Hollow rectangular

b) Solid circular

c) Hollow circular

d) Solid rectangular

Answer: c

Explanation: Piston pin is made of the hollow circular cross-section to reduce its weight. However, the strength of solid circular-section is equal to a hollow circular cross-section.

3. Piston pin passes through which part of the piston?

a) Oil ring

b) Riffle hole

c) Piston bosses

d) Compression ring

Answer: c

Explanation: Piston pin passes through the piston bosses provided on the inner side of the piston skirt and a bearing bush inside the small end of a connecting rod.

4. The end movement of the piston pin is restricted by which component?

a) Circlip

b) Welding

c) Bolting

d) Riveting

Answer: a

Explanation: The end movement of the piston pin is restricted by the means of the circlip, circlip is a thin circular wire that is connected on both the side of the piston pin.

5. Calculate the resisting force when (P b ) l =5N/mm 2 , d 0 =110mm, l 1 =67?

a) 73426N

b) 36850N

c) 238746N

d) 28642N

Answer: b

Explanation: Resisting force=(P b ) l d 0 l 1

= 5×110×67

= 36850N

6. What is the formula to calculate resisting force?

a) Resisting force=(P max ) l d 0 l 1

b) Resisting force=(P b ) l d i l 1

c) Resisting force=(P b ) l d 0 l 1

d) Resisting force=(P b ) l d 0 l s

Answer: c

Explanation: The formula to calculate Resisting force is (P b ) l d 0 l 1 where (P b ) l is the bearing pressure at the bush, d 0 is the outer diameter and l 1 is the length of the piston pin.

7. Calculate the inner diameter of the piston when the outer diameter is 50mm?

a) 30mm

b) 25mm

c) 40mm

d) 35mm

Answer: a

Explanation: Inner diameter d i =0.6×d 0

= 0.6×50

= 30mm

8. Calculate the mean diameter of the piston boss for grey cast iron piston, when d o =50mm?

a) 30mm

b) 50mm

c) 60mm

d) 70mm

Answer: d

Explanation: Mean diameter of piston bosses d i =1.4×d 0

= 1.4×50

= 70mm

9. Calculate the mean diameter of the piston boss for aluminum alloy piston, when d o =50mm?

a) 60mm

b) 70mm

c) 80mm

d) 90mm

Answer: c

Explanation: Mean diameter of piston bosses d i =1.6×d 0

= 1.6×50

= 80mm

10. The small gap between the cylinder liner and piston is known as _____

a) piston rib

b) piston clearance

c) piston head

d) wrist clearance

Answer: b

Explanation: Piston clearance is the clearance between the cylinder liner and piston that is provided to take care of thermal expansion and distortion under load.

This set of Advanced Automotive Engine Auxiliary Systems Questions and Answers focuses on “Engine Components – Connecting Rod”.

1. Based on which forging technique is the connecting rod forged?

a) Closed die forging

b) Press forging

c) Drop forging

d) Open die forging

Answer: c

Explanation: A connecting rod is drop forged component wherein a heavy hammer is dropped from a height of 1-1.5 meters, on to a hot workpiece kept on an anvil. The force of the blow varies from 10-3000 Newtons.

2. Which of the following is the proper measurement of the connecting rod length?

a) Length of shank

b) Length between the small end and big end axis

c) Length between the small end and the length of the shank

d) Length between the big end and the length of the shank

Answer: b

Explanation: The length of the connecting rod is the length from the small end axis and the big end cap axis of the connecting rod. This length also contains the shank length in it thus the length of the connecting rod is calculated.

3. Buckling is found in which part of the engine?

a) Intake manifold

b) Piston

c) Connecting rod

d) Glow plug

Answer: c

Explanation: Buckling can be experienced in a connecting rod and not in other components. The buckling is the deflection of the connecting rod therefore the buckling stress is found out for each material that is being used for the connecting rod.

4. Which are the combination of stresses acting on the connecting rod?

a) Shear and torsion

b) Torsion and tensile

c) Tensile and

d) Axial and bending stresses

Answer: d

Explanation: A combination of axial and bending stresses acting on the connecting rod in operation. The axial stresses are produced due to cylinder gas pressure and the inertia force arising on account of reciprocating motion, whereas bending stress caused due to centrifugal.

5. Identify the following part of the connecting rod shown below?

a) Shank

b) Bush

c) Float

d) Plunger

Answer: a

Explanation: The shank is the part that connects both the small end and the big end of the connecting rod. The cross-section of the shank portion of the connecting rod is an I-section. This I-section is made to blend smoothly into the two rod-ends.

6. Which of the following does the connecting rod connect?

a) Piston and crankshaft

b) Accelerator pedal and venturi

c) Cam and crankshaft

d) Sleeve and cotter

Answer: a

Explanation: The connecting rod converts the linear motion of the piston into rotary motion of the crankshaft. The connecting rod connects the piston and the crankshaft. The tensile strength of the connecting rod is in the range if 1034MPa.

7. For which to which part is the hole drilled for lubrication in a connecting rod?

a) Piston to crankshaft

b) Piston to connecting rod

c) Small end to big end of the connecting rod

d) Only in piston

Answer: c

Explanation: For lubrication, a rifle hole is drilled from the small end of the connecting rod to the big end of the connecting rod. The oil is lifted from the crankcase with higher pressure and lubricates cylinder through oil rings.

8. Which of the following material is used in the manufacturing of the connecting rod?

a) Magnesium

b) Copper

c) Bronze

d) Steel

Answer: d

Explanation: The connecting rod is generally made up of drop forging of steel or duralumin. However, with the technology these days cast from malleable or spheroidal graphite cast iron. Forged connecting rods are comparatively cheaper and have less strength.

9. Which of the following is defined as whipping stress?

a) Bending stress due to compression

b) Bending stress due to inertia

c) Bending stress due to

d) Bending stress due to torsion

Answer: b

Explanation: The small end of the connecting rod is subjected to translation motion and the big end is subjected to pure rotary motion. The intermediate point moves in an elliptical orbit. The lateral oscillation induces inertia that acts all along the length. This type of action is called whipping. The bending stress due to the inertia force is called whipping stress.

10. Which of the following formula is used to find the force acting on the connecting rod neglecting the cos theta angle and position of the connecting rod?

a) Force=Maximum gas pressure ×

b) Force=

c) Force=(π×D 2/4 )×maximum gas pressure

d) Force=(D 2/4 )× Stroke length

Answer: c

Explanation: The correct relationship the force acting on the piston is found using Force =(π×D 2/4 )×maximum gas pressure where D is the cylinder bore, maximum gas pressure is in the range of MPa or N/mm 2 .

11. Which of the following shows the correct relationship between critical buckling and force acting on the connecting rod?

a) Critical buckling load = factor of safety ×force on connecting rod

b) Critical buckling load = Factor of safety

c) Critical buckling load = force on the connecting rod

d) Critical buckling load = force on the connecting rod /factor of safety

Answer: a

Explanation: The correct relationship between the Critical buckling load and the force acting on the connecting rod is Critical buckling load = factor of safety ×force on connecting rod where critical buckling load is in terms of Newton and factor of safety is usually 5 to 6.

12. What is the percentage of carbon present in a medium carbon steel type connecting rod?

a) 0-0.1

b) 0.1-0.2

c) 0.25-0.35

d) 0.35-0.45

Answer: d

Explanation: The material used for the connecting rod is either medium carbon steel or alloy steel. The medium carbon steels contain 0.35-0.45 percentage carbon. The alloy steel includes nickel-chromium or chromium-molybdenum steels.

13. In splash lubrication, the spout is attached to with part of the connecting rod?

a) Piston

b) Shank

c) Big end

d) Small end

Answer: c

Explanation: In splash type lubrication a split is attached to the big end of the connecting rod and set at an angle to the axis of the rod. The spout dip into the sump of lubricating oil during the downward motion of the connecting rod and splashes the oil as the connecting rod moves up.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Buckling of Connecting Rod”.

1. Connecting rod is subjected to which type of force during buckling?

a) Axial strain

b) Shear stress

c) Tensile force

d) Compressive force

Answer: d

Explanation: The Connecting rod is subjected to axial compressive force equal to maximum gas load on the piston. The compressive stress is of significant magnitude.

2. Connecting rod experiences load from which part of the engine?

a) Cylinder

b) Cylinder head

c) Piston

d) Crankshaft

Answer: c

Explanation: Connecting rod top part i.e., small end is connected to the piston, and the piston experience maximum gas pressure during. Hence, connecting rod experiences load from the piston.

3. The connecting rod is designed as a _____

a) square

b) guideways

c) strut

d) cylinder

Answer: c

Explanation: The connecting rod should be very stiff and have good strength to withstand the load. Therefore, the connecting rod is designed as a column or strut.

4. The buckling of the connecting rod has how many planes?

a) 2 planes

b) 1 plane

c) 3 planes

d) 6 planes

Answer: a

Explanation: The buckling is the Bending of the connecting rod. The buckling of the connecting rod is in two different planes- the plane of motion and a plane perpendicular to the plane of motion.

5. The planes of the connecting rod are parallel to each other.

a) True

b) False

Answer: b

Explanation:The buckling of the connecting rod is in two different planes- the plane of motion and a plane perpendicular to the plane of motion. Therefore, the statement is false.

6. The ends of the connecting rod are _____ to the piston pin.

a) beam

b) fixed support

c) hinged

d) roller support

Answer: c

Explanation: In the plane of motion, the ends of the connecting rod are hinged to crankpin and piston pin.Hinge is one kind of support used to obtain eccentric motion. Therefore, the hinge is the right answer.

7. Buckling of the connecting rod is along which axis?

a) XX- axis

b) YY-axis

c) ZZ-axis

d) XY-axis

Answer: a

Explanation: In the plane of motion, the buckling of the connecting rod is along XX-axis and the end fixity coefficient is one. Hence, XX-axis is the right answer.

8. The ends of the connecting rod are fixed due to which effect?

a) Parallel effect

b) Perpendicular effect

c) Non-constraining effect

d) Constraining effect

Answer: d

Explanation: In the plane perpendicular to the plane of motion, the ends of the connecting rod are fixed due to the constraining effect of the bearing at the crankpin and the piston pin.

9. What is the coefficient of fixity along the YY-axis in buckling of connecting rod?

a) 1

b) 3

c) 4

d) 2

Answer: c

Explanation: In the plane perpendicular to the plane of motion, for the buckling about the YY-axis, the end fixity coefficient is 4. For a hinge support coefficient of fixity is zero.

10. What is buckling of connecting rod?

a) Straightening

b) Bending

c) Widening

d) Elongation

Answer: b

Explanation: Due to the compressive load from the piston and crankshaft, the connecting rod tends to bend. This bending of the connecting rod is known as the buckling of the connecting rod.

This set of Automotive Engine Design Interview Questions and Answers for Experienced people focuses on “IC Engine – Cross-Section for Connecting Rod”.

1. In the formula P=P c cos∅, what is P c ?

a) The pressure acting on the camshaft

b) Force acting on the camshaft

c) The pressure acting on connecting rod

d) Force acting on connecting rod

Answer: d

Explanation: In the formula P=P c cos∅, P is the force acting on the piston, P c is the force acting on connecting rod and ∅ is the angle of inclination of connecting rod with the line of stroke.

2. Find the force acting on the piston when the force acting on connecting rod is 40N and the angle of inclination is 20°?

a) 35N

b) 30KN

c) 37.5N

d) 40KN

Answer: c

Explanation: Force acting on piston is P e =P c cos∅

= 40×cos20

= 37.5N

3. Find the cross-sectional area of the connecting rod when the thickness of the web is 15mm?

a) 2651mm 2

b) 1265mm 2

c) 2475mm 2

d) 2561mm 2

Answer: c

Explanation: A=11t 2

=11×15 2

=2475mm 2

4. Find the radius of gyration when the thickness of the web is 15mm?

a) 26.7mm

b) 17.6mm

c) 19.7mm

d) 28.6mm

Answer: a

Explanation: Radius of gyration K xx =1.78t

= 1.78×15

= 26.7mm

5. Which of the mentioned below is the Rankine’s formula?

a) P cr =\

 

 

 P cr =\

 

 

 P cr =\

 

 

 P cr =\(\frac{\sigma_cA^2}{1+a

 

}\)

Answer: b

Explanation: The Rankine’s formula is given by P cr =\(\frac{\sigma_cA}{1+a

 

}\) where p c is the force on connecting rod, A is the cross-sectional area, L is the length of connecting rod, a is end fixity coefficient, σ c is stress and K xx is the radius of gyration.

6. In the formula P cr =\(\frac{\sigma_c A}{1+a

 

}\) what is K xx ?

a) Radius of cylinder

b) Constant

c) Radius of gyration

d) The radius of the big end

Answer: c

Explanation: Here p c is the force on connecting rod, A is the cross-sectional area, L is the length of connecting rod, a is end fixity coefficient, σ c is stress and K xx is the radius of gyration.

7. What is the height of the connecting rod at the middle section when t=25mm?

a) 125mm

b) 225mm

c) 95mm

d) 150mm

Answer: a

Explanation: Height of the connecting rod at the middle section is H=5t

= 5×25 = 125mm

8. What is the Height of connecting rod at the small end when H=125mm?

a) 50.85 to 90.60mm

b) 100.5 to 130.89mm

c) 105 to 122.6mm

d) 93.75 to 112.5mm

Answer: d

Explanation: Height of connecting rod at the small end is H 1 =0.75H to 0.9H

= 0.75×125 to 0.9×125

= 93.75 to 112.5mm

9. What is the Height of connecting rod at the big end when H=125mm?

a) 135 to 180.25mm

b) 124.56 to 160mm

c) 135.5 to 156.25mm

d) 110.89 to 111.90mm

Answer: c

Explanation: Height of connecting rod at the big end is H 2 = 1.1H to 1.25H

= 1.1×125 to 1.25×125

= 135.5 to 156.25mm

10. In which lubrication system oil is fed under high pressure?

a) Splash system

b) Pressure feed system

c) Lift system

d) Feed system

Answer: b

Explanation: In the Pressure feed lubrication system the oil is pumped under high pressure using a pump connected to crankshaft and oil lines.This system is used mainly in car engines for better cooling.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “ IC Engine – Big and Small End Bearings”.

1. Which material is used in piston pin bearing?

a) Nickel-chromium

b) Silver

c) Iron

d) Phosphor bronze

Answer: d

Explanation: The piston pin bearing is usually a phosphor bronze of 3 mm thickness and it is an alloy of copper; it has good strength and corrosion resistance.

2. Using which process piston pin bearing is manufactured?

a) Forming

b) Forging

c) Casting

d) Machining

Answer: c

Explanation: It is a solid one-piece bush, made by casting and then finished by grinding and reaming operations. Grinding is done to reduce the friction and gives a shiny surface. Hence, casting is the right answer.

3. What is the l/d ratio for the crank pin?

a) 1 to 2.5

b) 1.5 to 1.9

c) 1.25 to 1.5

d) 1.67 to 1.9

Answer: c

Explanation: The allowable bearing pressure for the crankpin bush is usually taken from 5 to 10MPa, for this value the l/d ratio of crankpin is from 1.25 to 1.5.

4. In the formula P c =d p l p (p b ) p what is d p ?

a) Inner Diameter of the bush

b) Outer Diameter of the bush

c) Inner Diameter of the bore

d) Outer Diameter of the bore

Answer: a

Explanation: In the formula, P c is the force acting on the piston pin, d p is the diameter of the piston pin, l p is the length of piston pin, (p b ) p is the allowable bearing pressure.

5. Calculate the diameter of the piston pin when P c =42951.46, l p =1.8dp, and (p b ) p =14?

a) 35.88mm

b) 41.28mm

c) 45.89mm

d) 39.33mm

Answer: b

Explanation: By the formula P c =d p l p (p b ) p

42951.46=d p ×1.8d p ×14

d p =41.28mm

6. In the formula P c =d c l c (p b ) c , what is the unit of l c ?

a) m

b) km

c) mm

d) N-mm

Answer: c

Explanation: In the formula, d c is the diameter of the piston pin, (p b )c is the allowable bearing pressure, l c is the length of piston pin, and is taken in mm.

7. Calculate the diameter of crankpin when P c =42951.46, l c =1.1dp and (p b ) c =8.5?

a) 67.78mm

b) 77.65mm

c) 57.23mm

d) 47.54mm

Answer: a

Explanation: By the formulaP c =d c l c (p b ) c

42951.46=d c ×1.1d p ×8.5

d c =67.78mm

8. In low-speed engines, L/r ratio varies from?

a) 2

b) 5 to 7

c) 3

d) 4 to 5

Answer: d

Explanation: In low-speed engines, connecting rods havea circular cross-section, this section can withstand the force when L/r ratio is 4 to 5.

9. Most connecting rods in high-speed engines have which cross-section?

a) T-section

b) Square

c) I-section

d) C- section

Answer: c

Explanation: I-sections are efficient in terms of material usage, it can bear high loads and can reduce the deflections. High-speed engines are with V-configuration and more than 4 cylinders. Hence, I-section is used.

10. Low-speed engines have which cross-section?

a) Rectangular-section

b) Circular-section

c) Square-section

d) Triangular-section

Answer: b

Explanation: Low-speed engines have L/r of 4 to 5, to bear this load circular section is very good. Low-speed engines are with 4 or less than 4 cylinder engines. Hence, low-speed engines have a circular section.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Big End Cap and Bolts”.

1. Which force is experienced by the connecting rod cap?

a) Gravity force

b) Magnetic force

c) Axial force

d) Inertia force

Answer: d

Explanation: The maximum force experienced by the connecting rod cap and bolts consists only of inertia force at the top dead Centre on the exhaust stroke. Hence, the inertia force is experienced by the connecting rod cap.

2. At which position of the piston, connecting rod cap experience inertia force?

a) Center

b) Side dead center

c) Top dead center

d) Bottom dead center

Answer: c

Explanation: The maximum force experienced by the connecting rod cap and bolts consists only of inertia force at the top dead center on the exhaust stroke. Hence, connecting rod cap experience inertia force at the top dead center.

3. Inertia force acting on the connecting rod cap is given by?

a) P i =m r ω 2 r

 

\)

b) P i =m r ω 2 r

 

\)

c) P i =m r ω 2 r

 

\)

d) P i =m r ω 2 r

 

\)

Answer: c

Explanation: P i =m r ω 2 r

 

\)is the right answer where Pi is the inertia force, m r is the mass of reciprocating parts, ω is the angular velocity of the crank, r is the crank radius, n1 is the ratio of L/r and θ is the angle of inclination.

4. Calculate the mass of reciprocating parts when the mass of piston assembly is 0.6Kg and mass of the connecting rod is 0.4Kg?

a) 0.73Kg

b) 0.85Kg

c) 0.6Kg

d) 0.43Kg

Answer: a

Explanation: m r = mass of piston assembly+ \

 

 

= 0.73Kg

5. Find the crank radius when the length of the stroke is 80mm?

a) 10mm

b) 40mm

c) 30mm

d) 50mm

Answer: b

Explanation: Crank radius r=\(\frac{l}{2}\) =\(\frac{80}{2}\) =40mm

6. Find the angular velocity of the crank rotating at 1200RPM?

a) 100.86rad/sec

b) 112.54rad/sec

c) 125.65rad/sec

d) 134.89rad/sec

Answer: c

Explanation: ω=\(\frac{2\times \pi\times N}{60}\)

=\(\frac{2\times \pi\times 1200}{60}\)

= 125.66 rad/sec

7. In the formula (P i ) max =m r ω 2 r

 

\) what is m r ?

a) Mass of reciprocating parts

b) Mass of all parts

c) Mass of cylinder

d) Mass of crankshaft

Answer: a

Explanation: In this formula, (P i ) max is the maximum inertia force, m r is the mass of reciprocating parts, ω is the angular velocity of the crank, r is the crank radius, n 1 is the ratio of L/r.

8. Calculate the inertia force where the diameter of bolts is 10mm and σ t =35N/mm 2 ?

a) 5555.5N

b) 6107.8N

c) 6478.6N

d) 5497.7N

Answer: d

Explanation: (P i ) max =2

 

\)σ t

=2\

 

\)× 35

=5497.7N

9. Calculate the bending moment on the cap when (P i ) max =400N and span length is 80mm.

a) 3567.9N-mm

b) 4789N-mm

c) 5333.3N-mm

d) 6893.89N-mm

Answer: c

Explanation: Mb=\(\frac{

_{max}l}{6}\)

=\(\frac{400×800}{6}\)

=5333.3N-mm

10. Calculate the thickness of cap when σ b =100N/mm 2 , M b =90853.95N-mm, y=\(\frac{t_c}{2}\) and I=6.25t c 3 ?

a) 7.65mm

b) 8.53mm

c) 9.7mm

d) 6.23mm

Answer: b

Explanation: σ b =\(\frac{M_b \times y}{I}\)

100=\(\frac{90853.95\times \frac{t}{2}}{6.25t^3}\)

t c =8.53mm

This set of Automotive Engine Components Design Questions & Answers for Exams focuses on “IC Engine – Whipping Stress”.

1. The small end of connecting rod experience which motion?

a) Rotary motion

b) Circular motion

c) Epicyclic motion

d) Translation motion

Answer: d

Explanation: The small end of the connecting rod is subjected to pure translation motion while the big end is subjected to pure rotary motion. The translation motion is by piston.

2. The big end of connecting rod experience which motion?

a) linear motion

b) Reciprocating motion

c) Rotary motion

d) Epicyclic motion

Answer: c

Explanation: The big end of the connecting rod is subjected to pure rotary motion. This rotary motion is by the crankshaft, which is connected through a big end cap with bolts.

3. The intermediate points on the connecting rod move in which orbit?

a) Rectangular orbit

b) Circular orbit

c) Elliptical orbit

d) Triangular orbit

Answer: c

Explanation: The intermediate points on the connecting rod move in elliptical orbits. It is a special case of a circular orbit, with eccentricity equal to 0.

4. The bending stress due to inertia force is known as _________

a) Whipping stress

b) Axial stress

c) Shear stress

d) Angular stress

Answer: a

Explanation: The lateral oscillations of the connecting rod induce inertia forces that act all along the length of the connecting rod causing bending. This type of action is called whipping stress.

5. What is the formula for the mass of the connecting rod when l=1?

a) A=ρm

b) m i =Aρ

c) ρ=m l A

d) σ=mρ

Answer: b

Explanation: The Mass of the connecting rod is given by m1= volume ×density

m1= area ×length ×density

m1= A

m1= Aρ

6. Calculate the area of cross-section when the thickness of the web is 5mm?

a) 190mm 2

b) 210mm

c) 275mm 2

d) 198mm

Answer: c

Explanation: A=11t 2

= 11×5 2

= 275mm 2

7. In the formula (M b ) max =mω 2 \

 

 m

b) Km

c) mm

d) Cm

Answer: a

Explanation: In this formula m is the mass of connecting rod, r is the crank radius and L is the length of connecting rod, and r is taken in meters.

8. In the formula m=m l L, what is the unit of m?

a) g

b) Ton

c) m

d) Kg

Answer: d

Explanation: Here m is the mass of connecting rod, ml is the mass of connecting rod per unit length and L is the length of connecting rod, and mass is taken in Kg.

9. Calculate the whipping stress when M b =105.14Kn-mm, y=20mm, and I=143018.66mm 4 ?

a)11.8N/mm 2

b)13.79N/mm

c)14.7N/mm 2

d)15.9N/mm

Answer: c

Explanation: \(\sigma=\frac{M_bY}{I}\)r

= \(\frac{105.14×10^3×20}{143018.66}\)

= 14.7N/mm 2

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “ IC Engine – Crankshaft”.

1. Which of the mentioned below is not a portion of the crankshaft?

a) Crankpin

b) Crank web

c) Connecting rod

d) Gudgeon pin

Answer: c

Explanation: Crankpin, crank web, gudgeon pin are all the connecting parts of the crankshaft with other components and connecting rod is a component that connects piston and crankshaft.

2. The big end of the connecting rod is connected to which portion of the crankshaft?

a) Shaft

b) Spigot

c) Crankpin

d) Spline

Answer: c

Explanation: The big end of the connecting rod is attached to the crankpin and the crank web connects the crankpin to the shaft portion. The connecting rod is bolted to the crankshaft.

3. Crank web connect the_____ to the shaft portion.

a) spline

b) spigot

c) crankpin

d) crank web

Answer: c

Explanation: The big end of the connecting rod is attached to the crankpin and the crank web connects the crankpin to the shaft portion. Based on the firing order the crank web is designed.

4. The crankshaft seat on which part and transmit power?

a) Main bearing

b) Small bearing

c) Ball-bearing

d) Minor bearing

Answer: a

Explanation: The shaft portion rotates in the main bearings and transmits power to the outside source through the belt drive, gear drive, or chain drive.

5. Which are the two types of the crankshaft?

a) Center crankshaft

b) Side and center crankshaft

c) Side shaft

d) Top and bottom crankshaft

Answer: b

Explanation: There are two types of crankshaft side crankshaft and center crankshaft. Side crankshaft is also called the overhung crankshaft.Side crankshaft is supported by two bearings.

6. The side crankshaft is also called as _____

a) convex crankshaft

b) suspended crankshaft

c) overhung crankshaft

d) concave crankshaft

Answer: c

Explanation: There are two types of crankshaft side crankshaft and center crankshaft. Side crankshaft is also called the overhung crankshaft. One end of the side crankshaft acts as a cantilever.

7. Side crankshaft has how many bearings?

a) Two bearings

b)Three bearings

c) Four bearing

d) Five bearing

Answer: a

Explanation: Side crankshaft has only one crank web and requires only two bearings for support. Hence Side crankshaft has two bearings.One end of the side crankshaft acts as a cantilever.

8. Centre crankshaft has how many bearings?

a) Six bearing

b) One bearing

c) Two bearing

d) Three bearings

Answer: d

Explanation: The center crankshaft has two webs and three bearings for support. It is used in radial aircraft engines. Hence, center crankshaft three has bearings.

9. Which are the two types of crankshaft based on many crankpins?

a) Single and double throw

b) Two and multi throw

c) Single throw and multi throw

d) Multi throw

Answer: c

Explanation: Crankshafts are also classified as single-throw and multi-throw crankshaft depending upon the number of crankpins. Hence, Single throw and multi throw is the right answer.

10. Single throw crankshaft has how many crankpins?

a) Two crankpins

b) One crankpin

c) Three crankpins

d) Five crankpins

Answer: b

Explanation: The single throw crankshaft has one crankpin and multi throw crankshaft has more than one crank pin. Single throw has a single web per Crankpin. Hence, One crankpin is the right answer.

11. A crankshaft having more than one or more crankpin is known as?

a) Double throw crankshaft

b) Multi throw crankshaft

c) Single throw crankshaft

d) Single and double throw crankshaft

Answer: b

Explanation: The single throw crankshaft has one crankpin and multi throw crankshaft has more than one crank pin. Multi throw crankshaft is used in high-performance engines.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “ IC Engine – Design of Centre Crankshaft”.

1. Which are the two forces experienced by the center crankshaft?

a) Tensile and compressive

b) Tensile and Bending

c) Compressive and torsional

d) Bending and torsional

Answer: d

Explanation: The Crankshaft is subjected to the bending and torsional moments due to force by crankpin, the weight of flywheel and belt tension.

2. Force is exerted by connecting rod on which portion of the crankshaft?

a) Gudgeon pin

b) Spigot

c) Crankpin

d) Pin

Answer: c

Explanation: Force is exerted by the connecting rod on the crankpin and this force obtained by the piston. Crankpin connects both the connecting rod and the crankshaft.

3. Weight of flywheel force, always act on which direction?

a) Horizontally leftward

b) Horizontally rightward

c) Vertically downward

d) Vertically upward

Answer: c

Explanation: Weight of flywheel acts downward in the vertical Direction and resultant belt tension acts in the horizontal direction . Flywheel balances the rotating crankshaft.

4. Resultant belt tension from the flywheel acts in which direction?

a) Horizontal

b) Right side

c) Forward

d) Vertical

Answer: a

Explanation: Weight of flywheel acts downward in the vertical Direction and resultant belt tension acts in the horizontal direction . V-belts are used very often in automobiles.

5. At what position, crankshaft experience maximum bending moment?

a) Bottom dead center

b) Top dead center

c) Middle position

d) Dead center

Answer: b

Explanation: The crank is at the top dead center position and subjected to maximum bending moment and no torsional moment. At this position Piston, the connecting rod forms a straight axis. So bending takes place.

6. What is the value of the torsional moment when the crankshaft is at the top dead center?

a) Bending moment

b) Torsional moment

c) No torsional moment

d) Stress

Answer: c

Explanation: The crank is at the top dead center position and subjected to maximum bending moment and no torsional moment. Torsional moment is a twisting force.

7. When does crankshaft experience a maximum torsional moment?

a) At angled position

b) At zero degree

c) At 180 degree

d) At 360 degree

Answer: a

Explanation: The crank is at an angle with the line of dead center positions and subjected to maximum torsional moment. Angled position is when the piston is in the middle of the cylinder.

8. The crankshaft is manufactured using which process?

a) Drop casting

b) Split casting

c) Casting

d) Drop forging process

Answer: d

Explanation: The crankshaft is subjected to fluctuating stresses and it should have sufficient endurance limit stress. Parts manufactured with Forging can withstand high stresses

9. Which material is used for crankshaft?

a) Carbon steel

b) Carbon fiber

c) Plain carbon steel

d) Bulged carbon steel

Answer: c

Explanation: The popular materials used for crankshaft are plain carbon steels and alloy steels. The plain carbon steels include 40C8 and 50C4.This results in lightweight, and less wear and tear.

10. Which alloy steels are used for making crankshaft?

a) Bronze

b) Nickel-chromium steels

c) Chromoly

d) Plane steel

Answer: b

Explanation: The alloy steels used for making crankshaft are nickel-chromium steels such as 16NiCr2, 35NiCr2, and 40Ni10Cr3Mo6. Hence, nickel-chromium steels are the right answer.

This set of Automotive Engine Design Question Paper focuses on “IC Engine – Centre Crankshaft at TDC Position”.

1. Which type of crankshaft is supported by three bearings?

a) Top crankshaft

b) Bottom crankshaft

c) Side crankshaft

d) Center crankshaft

Answer: d

Explanation: The forces acting on the centre crankshaft at the top dead centre position are three principle forces and to withstand this, the crankshaft is supported by three bearings.

2. In the design of centre crankshaft at TDC position, the driven belt is assumed to be in which direction?

a) Vertical

b) Angled

c) Horizontal

d) Perpendicular

Answer: c

Explanation: A crankshaft is subjected to bending and torsional moments due to the following three forces. Hence, In the design of centre crankshaft at the TDC position, the driven belt is assumed to be ina horizontal direction.

3. In the design of centre crankshaft at TDC position, the crank alone is at which position?

a) BDC position

b) ODC position

c) TDC position

d) HDF position

Answer: c

Explanation: A crankshaft is subjected to bending and torsional moments due to the following three forces. Hence, In the design of centre crankshaft at the TDC position, the crank alone is at the TDC position.

4. In the design of centre crankshaft at the TDC position, the engine is placed in which position?

a) Vertical

b) Horizontal

c) Parallel

d) Perpendicular

Answer: a

Explanation: A crankshaft is subjected to bending and torsional moments due to the following three forces. Hence, In the design of centre crankshaft at the TDC position, the engine is placed in a vertical position.

5. The reactions at the bearing 1 and 2 are due to force by which part of the crankshaft?

a) Circlip

b) Crankpin

c) Spigot

d) Key

Answer: b

Explanation: The reactions at the bearing 1 and 2 are due to force on the crankpin (P p ) and the reaction forces at the bearing are given R 1 and R 2 . Hence, crankpin the right answer.

6. The reactions at the bearing 2 and 3 are due to which part of the engine?

a) Weight of camshaft

b) Weight of connecting rod

c) Weight of flywheel

d) Weight of the gears

Answer: c

Explanation: The reactions at the bearing 2 and 3 are due to the weight of the flywheel and the sum of their belt tensions(P 1 +P 2 ) and reaction forces denoted by R 1 and R 2 .

7. The thrust in the connecting rod will be equal to the force acting on which part of the engine?

a) Piston

b) Connecting rod

c) Crankshaft

d) Gudgeon pin

Answer: a

Explanation: The thrust in the connecting rod will be equal to the force acting on the piston, this force is denoted by P p . The crankshaft is simply supported by the bearings.

8. Which plane of the crankshaft is subjected to the maximum bending moment?

a) Bottom plane

b) Top plane

c) Side plane

d) Central plane

Answer: d

Explanation: In the central plane of the crankshaft is subjected to a maximum bending moment. This moment is due to the force produced by the weight of the flywheel.

9. The right and left-hand webs should be identified based on which consideration?

a) Unbalanced

b) Unilateral

c) Balancing

d) lateral

Answer: c

Explanation: The right hand and left-hand webs should be identical from balancing considerations. So, the thickness and width of the right-hand crank web are made equal to that of the left-hand crank web.

10. The bending moment in the vertical plane is due to which part of the engine?

a) Weight of piston

b) Weight of flywheel

c) Weight of engine

d) Weight of vehicle

Answer: b

Explanation: The bending moment in the vertical plane is due to the weight of the flywheel and The bending moment in the horizontal plane is due to resultant belt tension.

11. The central plane of the crankpin is subjected to which force?

a) Minimum bending moment

b) Maximum bending moment

c) Normal stress

d) Principle stress

Answer: b

Explanation:The central plane of the crankpin is subjected to maximum bending moment and the bending moment at the central plane is given by (M b ) c =(R 1 ) v b 1 .

12. In the design of center crankshaft b=2D, what is D?

a) Valve diameter

b) Piston diameter

c) Gudgeon pin diameter

d) Shrinking diameter

Answer: b

Explanation: In the design of center crankshaft b=2D, b is the distance between bearing 1 and bearing 2 and D is the piston diameter. Hence, piston diameter is the right answer.

13. The bending moment in the horizontal plane is due to?

a) Belt compression

b) Resultant belt tension

c) Resultant tension

d) Resultant belt compression

Answer: b

Explanation: The bending moment in the vertical plane is due to the weight of the flywheel and the bending moment in the horizontal plane is due to resultant belt tension.

14. What is the dimension of crankweb when the diameter of crankpin is 50mm?

a) 25mm

b) 35mm

c) 40mm

d) 45mm

Answer: b

Explanation: Thickness of the crank web is given by t=0.7d c

t=0.7×50

=35mm

This set of Automotive Engine Components Design Questions and Answers for Freshers focuses on “IC Engine – Centre Crankshaft at Angle of Maximum Torque”

1. The maximum torque is due to which component of force on the crank pin?

a) Perpendicular

b) Parallel

c) Concentric

d) Tangential

Answer: d

Explanation: The torque is maximum when the tangential component of force on the crank pin is maximum. The force is produced due to the connecting rod.

2. What is the crank angle from the TDC position for the petrol engine?

a) 30° to 40°

b) 35° to 45°

c) 25° to 35°

d) 20° to 30°

Answer: c

Explanation:The crank angle from the TDC position for the petrol engine is 25° to 35° and the crank angle from the TDC position for the diesel engine is 30° to 40°.

3. What is the crank angle from the TDC position for diesel engines?

a) 35° to 45°

b) 25° to 35°

c) 30° to 40°

d) 20° to 30°

Answer: c

Explanation: The crank angle from the TDC position for the petrol engine is 25° to 35° and the crank angle from the TDC position for the diesel engine is 30° to 40°.

4. The relationship between Φ and θ is given by?

a) SinΦ=\

 

 CosΦ=\

 

 SinΦ=\

 

 CosΦ=\(\frac{cos\theta}{L/r}\)

Answer: a

Explanation: The relationship between Φ and θ is given by SinΦ=\(\frac{sin\theta}{L/r}\) where L is the length of the connecting rod and r is the radius of the crank.

5. In the formula SinΦ=\

 

 Lateral shift

b) Length of connecting rod

c) Linear bending

d) Length of stroke

Answer: b

Explanation: The relationship between Ф and ϴ is given by SinΦ=\(\frac{sin\theta}{L/r}\) where L is the length of the connecting rod and r is the radius of the crank.

6. In the formula P t =P q Sin, what is P t ?

a) The pressure at crankpin

b) The lateral component at crankpin

c) The tangential component at crankpin

d) Power at crankpin

Answer: c

Explanation: In the formula P t =P q Sin, P t is the tangential component of P q at the crankpin and P r is the radial component of P q at the crank pin.

7. In the formula P r =P q Sin, what is P r ?

a) The radial component at crankpin

b) Pressure component at crankpin

c) The tangential component at crankpin

d) Vector component at crankpin

Answer: a

Explanation: In the formula P r =P q Sin, P t is the tangential component of P q at the crankpin and P r is the radial component of P q at the crank pin.

8. Which are the two forces experienced by the crank pin?

a) Bending and shear moment

b) Two couple force

c) Force and torsional moment

d) Bending and torsional moment

Answer: d

Explanation: Bending and torsional moment are the two forces experienced by the crankpin and these forces are produced by bearing 1,2 and 3.

9. In the formula M t =P t ×r, what is M t ?

a) Couple

b) Bending moment

c) Torsional moment

d) Shear moment

Answer: c

Explanation: In the formula M t =P t ×r, M t is the torsional moment due to tangential component P t and r is the crank radius. Hence, the torsional moment is the right answer.

10. The right-hand crank web is subjected to which stress due to radial component.

a) Tensile

b) Compressive

c) Normal strain

d) Linear stress

Answer: b

Explanation: The right-hand crank web is subjected to compressive stress due to the radial component and bending moment in the vertical plane due to forces in the vertical plane.

11. The maximum compressive stress should be less than which stress?

a) Allowable tensile stress

b) Allowable compressive stress

c) Allowable shear stress

d) Allowable bending moment

Answer: b

Explanation: The maximum compressive stress should be less than allowable compressive stress if not the crankshaft tends to bend and wobbling takes place.

12. Calculate the width of the crank web when the diameter of crankpin is 65mm?

a) 57.3mm

b) 74.1mm

c) 63.7mm

d) 80.6mm

Answer: b

Explanation: w=1.14d c

=1.14×65

=74.1mm

13. Calculate the direct compressive stress when the reaction force is 15340N and the thickness and width of the crank web are 46mm and 75mm?

a) 8.43N/mm 2

b) 4.44N/mm 2

c) 5.54N/mm 2

d) 3.68N/mm 2

Answer: b

Explanation: σ c =\(\frac{

_v}{W_t}\)

\(\frac{15340}{46\times 75}\)

=4.44N/mm 2

14. In the formula σ c =\(\frac{

_v}{W_t}\) , what is (R 1 ) v ?

a) Point load

b) Eccentric load

c) UVL

d) UDL

Answer: b

Explanation: In the formula σ c =\frac{

_v}{W_t}[/latex], (R 1 ) v is the eccentric load, w is the width of the crank web and t is the thickness of the crank web.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Side Crankshaft at TDC Position”.

1. Which type of crankshaft is supported by two bearings?

a) Top crankshaft

b) Bottom crankshaft

c) Side crankshaft

d) Center crankshaft

Answer: c

Explanation: The forces acting on the center crankshaft at the top dead centre position are two principal forces and to withstand this, the crankshaft is supported by two bearings.

2. In the design of side crankshaft at TDC position, the driven belt is assumed to be in which direction?

a) Vertical

b) Angled

c) Horizontal

d) Perpendicular

Answer: c

Explanation: A crankshaft is subjected to bending and torsional moments due to the following two forces. Hence, In the design of centre crankshaft at the TDC position, the driven belt is assumed to be in a horizontal direction.

3. In the design of side crankshaft at TDC position, the crank alone is at which position?

a) BDC position

b) ODC position

c) TDC position

d) HDF position

Answer: c

Explanation: A crankshaft is subjected to bending and torsional moments due to the following three forces. Hence, In the design of side crankshaft at the TDC position, the crank alone is at the TDC position.

4. In the design of side crankshaft at the TDC position, the engine is placed in which position?

a) Vertical

b) Horizontal

c) Parallel

d) Perpendicular

Answer: a

Explanation: A crankshaft is subjected to bending and torsional moments due to the following two forces. Hence, In the design of side crankshaft at the TDC position, the engine is placed in a vertical position.

5. The reactions at the bearing 1 and 2 are due to which part of the engine?

a) Weight of camshaft

b) Weight of connecting rod

c) Weight of flywheel

d) Weight of the gears

Answer: c

Explanation: The reactions at the bearing 1 and 2 are due to the weight of the flywheel and the sum of their belt tensions(P 1 +P 2 ) and reaction forces denoted by R 1 and R 2 .

6. Calculate the length of the bearing when the diameter of crankpin is 50mm?

a) 35 to 55mm

b) 87 to 90mm

c) 75 to 100mm

d) 91 to 109mm

Answer: c

Explanation: l 1 =1.5d c to 2d c

=1.5×50 to 2×50

=75 to 100mm

7. In the formula P b =\(\frac{R_1}{d_1l_1}\), what is P b ?

a) Bearing pressure

b) Torsional moment

c) Force

d) Shear force

Answer: a

Explanation: In the formula P b =\(\frac{R_1}{d_1l_1}\), P b is the bearing pressure, R 1 is the reaction force at bearing 1, d 1 and l 1 are the diameter and length of bearing 1.

8. Calculate the bearing pressure when the reaction at 1 is 176700N and the length and diameter of crankpin are 120mm and 150mm.

a) 8.15N/mm 2

b) 7.89N/mm 2

c) 5.67N/mm 2

d) 9.81N/mm 2

Answer: d

Explanation: P b =\(\frac{R_1}{d_1l_1}\)

P b =176700/

=9.81N/mm 2

9. Calculate the bending moment when load is 176700N, length of bearing is 265mm, thickness is 90mm and length of crank pin is 120mm?

a) 8.738×10 6 N-mm

b) 89.3×10 6 N-m

c) 55.21×10 6 N-mm

d) 45.89×10 6 N-m

Answer: c

Explanation: M b =P p [0.75lc+t+0.5l 1 ]

=176700[0.75×120+90+0.5×265]

=55.21×10 6 N-mm

10. In the formula M b =P p [0.75l c +t+0.5l 1 ], what is l 1 ?

a) Length of shaft

b) Length of bearing

c) Length of connecting rod

d) Length of crank

Answer: b

Explanation: In the formula M b =P p [0.75l c +t+0.5l 1 ], M b is the bending moment, l c is the length of the crankpin, t is the thickness, l 1 is the length of the bearing 1.

11. Does the crank pin act as a which beam inside crankshaft?

a) Simply supported

b) Cantilever

c) Overhanging

d) Roller supported

Answer: b

Explanation: The crankpin acts as a cantilever beam inside crankshaft and subjected to maximum bending moment on the crankshaft.

12. When the crank web is subjected to stresses, bending stress acts on which plane?

a) Horizontal

b) Both horizontal and vertical

c) Vertical

d) normal

Answer: b

Explanation: When the crank web is subjected to stresses, bending stress acts on Both horizontal and vertical planes. This bending stress is equally divided on both the planes.

13. In the formula M t =P t ×r, what is P t ?

a) Vertical component

b) Tangential component

c) Horizontal component

d) Normal component

Answer: b

Explanation: In the formula M t =P t ×r, P t is the tangential component, M t is the torsional moment and r is the crank radius. To avoida torsional moment, torsional rigidity should be good.

14. What is the thickness of the crankweb when the diameter of the crankpin is 50mm?

a) 12.5 to 77.5mm

b) 22.5 to 37.5mm

c) 28.7 to 48.5mm

d) 31.9 to 34.0mm

Answer: b

Explanation: Thickness of the crank web is given by t=0.45d c to 0.75d c

t=0.45×50 to 0.75×50

=22.5 to 37.5mm.

This set of Automotive Engine Components Design Interview Questions and Answers for freshers focuses on “IC Engine – Side Crankshaft at Angle of Maximum Torque”.

1. In the formula sinΦ=\

 

 The angle of inclination of the crankshaft with the line of action

b) The angle of inclination of connecting rod with the line of action

c) The angle of inclination of the crankshaft with the line of dead centers

d) The angle of inclination of connecting rod with the line of dead centers

Answer: d

Explanation: In the formula sinΦ=\(\frac{sin⁡θ}{}\), Φ is the angle of inclination of connecting rod with the line of dead centers and ϴ is the angle of inclination of the crank with a line of dead centers.

2. In the formula sinΦ=\

 

𝛳 The angle of inclination of connecting rod with a line of dead centers

b) The angle of inclination of the crank with a line of action

c) The angle of inclination of the crank with a line of dead centres

d) The angle of inclination of the crank with connecting rod

Answer: c

Explanation: In the formula sinΦ=\(\frac{sin⁡θ}{}\), Φ is the angle of inclination of connecting rod with the line of dead centers and ϴ is the angle of inclination of the crank with a line of dead centres.

3. In the reaction (R 1 ) v , what does v represent?

a) Reaction on the central plane

b) Reaction on a horizontal plane

c) Reaction on a vertical plane

d) The horizontal and vertical plane

Answer: c

Explanation: In the reaction (R 1 ) v , where R 1 is the reaction at bearing 1 and v represents the reaction of the bearing 1 in the vertical component.

4. Calculate the bending moment, when P t =47900N and l c =170mm?

a) 8143KN-mm

b) 5983KN-mm

c) 9075KN-mm

d) 4578KN-mm

Answer: a

Explanation: M b =P t ×l c

=47900×170

=8143KN-mm

5. Calculate the length of the bearing when the diameter of the crankpin is 150?

a) 377mm

b) 262.5mm

c) 938.7mm

d) 654.27mm

Answer: b

Explanation: l 1 =1.75d c

=1.75×150

=262.5mm

6. In the formula l 1 =1.75d c , what is d c ?

a) Diameter of bore

b) The diameter of the connecting rod

c) The diameter of crankpin

d) Diameter of piston

Answer: c

Explanation: In the formula l 1 =1.75d c , l 1 is the length of the crankpin and d c is the diameter of the crankpin, generally d is always used to represent diameter.

7. Calculate the length of crankpin when the diameter of crankpin is 150?

a) 120mm

b) 178mm

c) 210mm

d) 160mm

Answer: a

Explanation: l c =0.8d c

= 0.8×150

= 120mm

8. In the formula c={\Extra close brace or missing open brace Diameter of piston

b) The diameter of the connecting rod

c) Diameter of bore

d) Width of flywheel

Answer: d

Explanation: In the formula c={\(\frac{l_1}{2}+t+\frac{l_2}{2}+m\)}, l 1 is the length of the bearing 1, l 2 is the length of the bearing 2, t is the width of flywheel and m is the excess part of crankshaft known as margin.

9. Calculate the tangential component, where P q =71260N, Φ=7.32, ϴ=35?

a) 21878N

b) 18979N

c) 47977N

d) 18978N

Answer: c

Explanation: P t =P q Sin𝛳

= 71260×sin 

= 47977N

10. Calculate the radial component, where P q =71260N, Ф=7.32, ϴ=35?

a) 89173.7N

b) 52689.3N

c) 21938.8N

d) 91732.18N

Answer: b

Explanation: P r = P q cos𝛳

= 71260×cos 

= 52689.3N

11. Find the symmetry reactions R1 and R2 when load acting is 10KN?

a) 12873N and 7178N

b) 5000N and 6000N

c) 9138N and 21876N

d) 6000N and 12000N

Answer: b

Explanation: r1=r2=\(\frac{W}{2}\)

=\(\frac{10000}{2}\)

=5000N

12. Which are the two stresses that act inside crankshaft?

a) Shear and bending stress

b) Compressive and bending stress

c) Tensile and compressive stress

d) Compressive and shear stress

Answer: b

Explanation: Compressive and bending stress are the two stresses that act inside crankshaft and two resist these two stresses a reactive force R1 and R2 are produced.

13. Which of the mentioned below is the formula for total compressive stress?

a) A+B=C

b) (σ c ) t =σ c +σ b

c) τ c =τ a +τ b

d) ρ=ω+σ

Answer: b

Explanation: (σ c ) t =σ c +σ b is the formula for total compressive stress, always stress is represented by σ and shear stress is represented by τ. Hence, (σ c ) t =σ c +σ b is the right answer.

Answer: b

Explanation: M b =\(\sqrt{

v^2+

h^2}\) is the equation of the resultant bending moment. Always resultant is the addition of horizontal and vertical components, and M b represents the bending moment.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “ IC Engine – Valve-Gear Mechanism”.

1. What is the function of the valve gear mechanism in the IC engine?

a) Only opening inlet and exhaust valve

b) Open and close the inlet and exhaust ports

c) Only closing inlet and exhaust valve

d) Open and close the inlet and exhaust valve

Answer: d

Explanation: The function of the valve gear mechanism in the IC engine is to open and close the inlet andexhaust valve. Open inlet valve to enter the charge and open exhaust valve to remove burnt gas.

2. The fuel is admitted into the cylinder, by opening which valve?

a) Exhaust

b) Ball port

c) Inlet

d) Non-return

Answer: c

Explanation: The fuel is admitted into the cylinder, by opening the inlet valve and the burnt gases escape from the engine by opening the exhaust valve. Inlet valve experience lesser then exhaust valve.

3. The burnt gases escape from the engine by opening which valve?

a) Inlet

b) Non-return

c) Exhaust

d) Inlet port

Answer: c

Explanation: The fuel is admitted into the cylinder, by opening the inlet valve and the burnt gases escape from the engine by opening the exhaust valve. Inlet valve experience lesser then exhaust valve.

4. Which of the parts mentioned below is not a part of the valve-gear mechanism?

a) Piston

b) Valve

c) Spring

d) Tappet

Answer: a

Explanation: Valve, spring, tappet are all part of a valve-gear mechanism, but the piston is the part that compresses the charge and experiences the heat that is present inside the cylinder.

5. The camshaft is rotated by which driving mechanism in cars?

a) Chain-drive

b) Belt-drive

c) Shaft-drive

d) Fluid drive

Answer: b

Explanation: The camshaft is rotated by Belt-drive mechanism in cars and this belt is also called a timing belt. In bikes, we have a timing chain supported by a torsion supporting bar.

6. As the camshaft rotates, the cam pushes the follower, and push rod is moved in which direction?

a) Downward

b) Parallel

c) Upward

d) Horizontal

Answer: c

Explanation: As the cam rotates,the cam pushes the follower, and push rod is moved in an upward direction and the rocker arm is pivoted at its centerutilizing Fulcrum pin.

7. The rocker arm is pivoted at its centerusing which pin?

a) Fulcrum

b) Key

c) Cotter

d) Spigot

Answer: a

Explanation: As the cam rotates,the cam pushes the follower, and pushrod is moved in an upward direction and the rocker arm is pivoted at its centerusing a Fulcrum pin.

8. When the right end of the rocker arm is pushed up, the left end moves in which direction?

a) Upward

b) Parallel

c) Perpendicular

d) Downward

Answer: d

Explanation: When the right end of the rocker arm is pushed up, the left end moves in a downward direction and pushes the spring-loaded valve to achieve the motion.

9. The opening of valves is due to which motion of the rocker arm?

a) Tangential motion

b) Reciprocating motion

c) Oscillatory motion

d) Rotating motion

Answer: c

Explanation: The opening of valves is due to the oscillatory motion of the rocker arm. This is due to the force by initial compression presses the valve down on its seat.

10. One end of the spring is secured to the valve stem and the other end rests on which part?

a) Piston

b) Cylinder

c) Oil pan

d) Cylinder head

Answer: b

Explanation: One end of the spring is secured to the valve stem and the other end rests on the cylinder. The cylinder is fixed support and withstands the high-pressure.

11. Follower rests on which part of the valve-gear mechanism?

a) Rocker-arm

b) Cam

c) Valve

d) Tappet

Answer: b

Explanation: One end of the spring is secured to the valve stem and the other end rests on the cylinder and the follower rests cams of the valve-gear mechanism.

12. What happens to the spring when the valve is opened?

a) Elongate

b) Compress

c) Twist

d) both compress and twist

Answer: b

Explanation: The spring gets compressed when valves are opened which means the cams are in action and push the push rod thereby rocker-arm. Depending on usage, the spring loses its strength.

This set of Automotive Engine Design Questions and Answers for Experienced people focuses on “IC Engine – Valves Design”.

1. Which are the two types of valves?

a) Sleeve and tapper valve

b) Mushroom and ball valve

c) Tapper and ball valve

d) Mushroom and sleeve valves

Answer: d

Explanation: Mushroom and sleeve valves are the two types of valves used in the internal combustion engines and the mushroom valves are also known as poppet valves.

2. What are the mushroom valves also known as?

a) Tapper valve

b) Sleeve valve

c) Poppet valve

d) Non-return valve

Answer: c

Explanation: Mushroom valves are also known as poppet valves. Since it consists of a stem and one end enlarged to form a head that permits the flow through a passage surrounding the stem, that resembles the shape of a mushroom.

3. What does the poppet valve consisting of a disk known as?

a) Face

b) Stem

c) Head

d) Shank

Answer: c

Explanation: The poppet valve that consists of a disk known as head and the poppet valve head at the end of a rod is known as the stem. Stem experience lesser heat compared to the face of the valve.

4. What is the poppet valve head at the end of a rod is known as?

a) Stem

b) Face

c) Head

d) Shank

Answer: a

Explanation: The poppet valve that consists of a disk known as head and the poppet valve head at the end of a rod is known as the stem. This experience lesser heat compared to the face of the valve.

5. Which part of the valve is a conical surface that comes in contact with a valve seat?

a) Head

b) Face

c) Stem

d) shank

Answer: b

Explanation: The poppet valve that consists of a disk known as the head, the poppet valve head at the end of a rod is known as stem and the valve is a conical surface that comes in contact with a valve seat known as a face.

6. What is the face angle range for a poppet valve?

a) 20° to 50°

b) 35° to 60°

c) 30° to 45°

d) 40° to 55°

Answer: c

Explanation: 30° to 45° is the face angle range for a poppet valve. The face angle and the face can be altered accordingly using grinding or skimming machines.

7. What is the small conical surface of the valve results in which property?

a) Self-centering

b) Increase in weight

c) Hardness

d) Strength

Answer: a

Explanation: The small conical surface of the valve results in Self-centering. This is one of the important properties if this neglected, the charge won’t be compressed properly.

8. What is the small space between the head and the face is known as?

a) Blank

b) Space

c) Stem

d) Margin

Answer: d

Explanation: The small space between the head and the face is known as margin and the poppet valve head at the end of a rod is known as the stem. The margin contributes to improve airflow and durability.

9. In heavy-duty engines, which material is used in the valves?

a) Silicon-Chromium steel

b) Nickel-Chromium steel

c) Chromium-vanadium steel

d) Hardened steel

Answer: c

Explanation: In heavy-duty engines, the valves are made by chromium-vanadium steel and in normal cars, nickel-Chromium steelor silicon-Chromium steel are used.

10. Which material is used in the Inlet valves?

a) Chromium-vanadium steel

b) Nickel-Chromium steel

c) Silicon-Chromium steel

d) Hardened steel

Answer: b

Explanation: Inlet valves are made of Nickel-Chromium steel and exhaust valves are made of Silicon-Chromium steel. In heavy-duty engines, the valves are made by chromium-vanadium steel.

11. Which material is used Exhaust valves?

a) Hardened steel

b) Silicon-Chromium steel

c) Nickel-Chromium steel

d) Chromium-vanadium steel

Answer: b

Explanation: Inlet valves are made of Nickel-Chromium steel and exhaust valves are made of Silicon-Chromium steel. In heavy-duty engines, the valves are made by chromium-vanadium steel.

Answer: b

Explanation: Valves are strengthened by both heat treating and surface hardening for inlet and exhaust at the temperature in the range 250 to 300HB.

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Rocker Arms Design”.

1. What is the basic function of the rocker arm, concerning the motion of the cam and follower?

a) Only opening inlet and exhaust valve

b) Open and close the inlet and exhaust ports

c) Only closing inlet and exhaust valve

d) Open or close the inlet or exhaust valve

Answer: d

Explanation: The basic function of the rocker arm, concerning the motion of the cam and follower, is to open or close the inlet or exhaust valve. This experience lot of heat.

2. To reduce the weight and inertia force of the rocker arm, which cross-section is used?

a) V-section

b) L-section

c) I-section

d) T-section

Answer: c

Explanation: To reduce the weight and inertia force of the rocker arm I-section cross-section is used. Whenever the inertia force is important, then I-section will be the first option.

3. Which of the mentioned below is not the material of rocker arm?

a) Grey-cast iron

b) Malleable cast iron

c) Chromium alloy

d) Cast steel

Answer: c

Explanation: Grey-cast iron, Malleable cast iron, Cast steel are all the material that is used in the manufacturing rocker-arm whereas chromium alloy is not usually used.

4. In a four-stroke engine, which valve is heavily loaded?

a) Exhaust

b) Inlet

c) Non-return

d) One way

Answer: a

Explanation: In a four-stroke engine, the exhaust valve is heavily loaded when compared to the inlet valve due to smaller in size and experience a lot of heat.

5. The force on which valve is less compared to others?

a) Non-return

b) Inlet

c) Ports

d) Exhaust

Answer: b

Explanation: In a four-stroke engine, the exhaust valve is heavily loaded when compared to the inlet valve and the force on the inlet valve is less comparing to the exhaust valve.

6. The maximum force exerted by the valve will determine which force on the rocker arm?

a) Torsional moment

b) Tangential moment

c) Bending moment

d) Both torsional and tangential moment

Answer: c

Explanation: The maximum force exerted by the valve will determine the bending moment on the rocker-arm. Hence, the bending moment is the right answer.

7. In the cross-section of the rocker arm, the bending moment is maximum at what point?

a) Centre of the pivot

b) Centre of gravity

c) Centre of mass

d) Centre of mass and pivot

Answer: a

Explanation: In the cross-section of the rocker arm, the bending moment is maximum at the Centre of the pivot point. Hence, the eye passing through this point is strengthened.

8. Which of the mentioned below is the formula to calculate the thickness of each eye?

a) t=\

 

 t=\

 

 t=\

 

 t=\(\frac{l}{2}\)

Answer: d

Explanation: t=\(\frac{l}{2}\) is the formula to calculate the thickness of each eye and D 2 =2d 2 is the formula to calculate the outer diameter of the eye. Hence, t=\(\frac{l}{2}\) is the right answer.

9. Which of the mentioned below is the formula to calculate the outer diameter of the eye?

a) D 2 =d 2

b) D 2 =2d 2 +2A 2

c) D 2 =2d 2

d) A 2 =2d 2 +2

Answer: c

Explanation: t=\(\frac{l}{2}\) is the formula to calculate the thickness of each eye and D 2 =2d 2 is the formula to calculate the outer diameter of the eye. Hence, D 2 =2d 2 is the right answer.

10. Which of the mentioned below is the formula to calculate the triangular distribution of the load between the pin and the eye?

a) x=\

 

 x=\

 

 x=\

 

 x=l 2

Answer: b

Explanation: x=\(\frac{l_2}{6}\) is the formula to calculate the triangular distribution of the load between the pin and the eye and D 2 =2d 2 is the formula to calculate the outer diameter of the eye.

11. Which of the mentioned below is the formula to calculate uniformly distributed load between the pin and the roller?

a) Z=\

 

 Z=\

 

 x=\

 

 x=l 2

Answer: b

Explanation: Z=\(\frac{l_2}{4}\)is the formula to calculate uniformly distributed load between the pin and the roller and t=\(\frac{l}{2}\) is the formula to calculate the thickness of each eye.

12. Calculate the diameter of the circular end of the rocker, when d=15mm?

a) 40mm

b) 30mm

c) 45mm

d) 7.5mm

Answer: b

Explanation: D 3 =2d

=2×15

=30mm

This set of Automotive Engine Components Design Multiple Choice Questions & Answers  focuses on “IC Engine – Valve Spring Design”.

1. The purpose of the valve spring is to exert force on which part?

a) Rocker arm

b) Tappet

c) Roller

d) Cam

Answer: a

Explanation: Piston and Cylinder liner are held very close together such that the clearance between them can be neglected and the purpose of the valve spring is to exert force on the rocker arm.

2. When valves are closed which pressure is built inside the cylinder?

a) Neutral pressure

b) Positive pressure

c) Negative pressure

d) Zero pressure

Answer: c

Explanation: The purpose of the valve spring is to exert force on the rocker arm and When valves are closed negative pressure is built inside the engine cylinder.

3. Calculate the mean coil diameter when C=8 and d=6?

a) 1.33mm

b) 48mm

c) 14mm

d) 2mm

Answer: b

Explanation: D=Cd

= 8×6

= 48mm

4. Calculate the total number of turns for a square and ground end when N=13?

a) 15

b) 13

c) 32

d) 10

Answer: a

Explanation: N1=N+2

= 13+2

= 15

5. Calculate the free length of the spring when the solid length is 90mm and δ max =35.75mm?

a) 145.9mm

b) 69.65mm

c) 656mm

d) 131.11mm

Answer: d

Explanation: Free length= solid length+δ max +0.15δ max

=90+35.75+0.15

= 131.11mm

6. Calculate the solid length of the spring, when N t =15mm and d=6mm.

a) 70mm

b) 90mm

c) 21mm

d) 9mm

Answer: b

Explanation: Solid length= L t d

= 15×6

= 90mm

7. Calculate the pitch of the coil when the free length is 131.11mm and N1 is 15mm?

a) 29.6mm

b) 9.37mm

c) 20mm

d) 12.3mm

Answer: b

Explanation: Pitch of coils=\(\frac{Free \, length}{}\)

=\(\frac{131.11}{}\)

= 9.37mm

8. Calculate the maximum force on the spring P max when P i =88.36N, K=10 and d=25mm.

a) 338.36N

b) 288.36N

c) 135.36N

d) 282.36N

Answer: a

Explanation: P max =P i +Kd

=88.36+10

=338.36N

9. Calculate the width of the flange, when thickness=8.

a) 30mm

b) 20mm

c) 10mm

d) 40mm

Answer: b

Explanation: Width of flange=2.5t

= 2.5

=20mm

10. Calculate the depth of the section when t=8mm.

a) 88mm

b) 38mm

c) 48mm

d) 127mm

Answer: c

Explanation:Depth of section=6t

=6×8

=48mm

This set of Automotive Engine Components Design Questions and Answers for Aptitude test focuses on “IC Engine – Push Rod Design”.

1. Pushrods are used in which type of valve mechanized engine?

a) Overhead valve

b) Side valve

c) Bottom face valve

d) Under the head valve

Answer: a

Explanation: Pushrods are used inoverhead valve type of valve mechanized engine and are connected between cam and rocker of the engine component. This uses a ball and socket mechanism.

2. Pushrods are connected between which two parts of the valve gear mechanism?

a) In the crankshaft

b) In the alternator

c) Cam and rocker

d) In the Fuel pump

Answer: c

Explanation: Pushrods are connected between cam and rocker of the engine component. These are hollow tubesmade by duralumin material. This results in good strength and low weight.

3. Which of the mentioned below material is used in pushrod?

a) Mild steel

b) Duralumin tube

c) Steel tube

d) Chromoly

Answer: b

Explanation: Pushrods are made of Duralumin tube, due to its low weight property. The sockets at the end of pushrod useball and socket joint with a grease for lubrication between it.

4. Which type of joint is used at the end of pushrod?

a) Ball and sockets

b) Ball and spigot

c) Socket and cotter

d) Cotter and key

Answer: a

Explanation: Ball and socket is the mechanism involved in pushrod. The socket is made at one end of the pushrod and ball is present in that. Above the ball, a tappet is present to reduce the friction.

5.The sockets at the end of the pushrod are connected by which fit?

a) Nut and bolt

b) Welding

c) Bracing

d) Force fit

Answer: d

Explanation: The sockets at the end of pushrod are connected by force fit and Ball and sockets are the two types of joints used at the end of the pushrod.

6. The pushrod is designed as a column based on what criteria?

a) Tensile

b) Buckling

c) Compressive

d) Both tensile and compressive

Answer: b

Explanation: The pushrod is designed as a column based on buckling criteria; pushrods are often subjected to a compressive force which results in buckling.

7. What is the cross-section of the pushrod?

a) Cylindrical

b) Circular

c) Square

d) Rectangular

Answer: b

Explanation: Pushrods are a hollow tube made by duralumin metal with a circular cross-section which results in a reduction of weight and high strength.

8. Pushrods are solid rod.

a) True

b) False

Answer: b

Explanation: Pushrods are made with a hollow rod. The main factor here is the weight, for the same work hollow rod is more efficient than a solid rod, and both the rods have the same strength.

9. Pushrods are in direct contact with valves?

a) True

b) False

Answer: b

Explanation: When cam pushes the tappet there is an opposite force from pushrod, pushrods are in direct contact with rocker arm and the tappet.So pushrods are not in direct contact with the valve.

10. Calculate the base circle diameter of cam, when bore diameter is 150mm?

a) 27.9mm

b) 28mm

c) 36.5mm

d) 38.9mm

Answer: c

Explanation:D=0.16d+12.5

=0.116 +12.5

= 36.5mm

Answer: d

Explanation: Tappets are subjected to a compressive force; tappet is connected between the cam and the pushrod. When cam pushes the tappet there is an opposite force from pushrod.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Methods of Cooling”.

1. In air-cooled small engines ______ are provided on the outer perimeter of the engine?

a) Flanges

b) Fins

c) Holes

d) Treads

Answer: b

Explanation: Fins are present on the outer perimeter of the engine as they increase the surface area of contact metal with the air by doing this heat is transferred from the engine through Fins, into the atmosphere thus achieving effective cooling is obtained.

2. The Principle used to dissipate the heat from water to atmosphere via Radiator in the sequence is ______and ______

a) radiation and Conduction

b) radiation and Convection

c) conduction and Convection

d) convection and Radiation

Answer: c

Explanation: Conduction occurs when the engine gets heated up and the heat is transferred from the combustion chamber to the water jacket where the water absorbs the heat. Convection takes place when the water becomes dense by absorbing the heat and which becomes less dense once it is passed through the radiator.

3. In Cooling system when the cooling is reached beyond the limits leads to______ of viscosity and ______ of the Mechanical Efficiency.

a) increase and Decrease

b) decrease and Increase

c) increase and Increase

d) decrease and Decrease

Answer: a

Explanation: As temperature and viscosity are inversely proportional to each other the viscosity of the lubricant Increase and due to this more piston friction is encountered thus Decrease of mechanical efficiency.

4. What is the correct sequence of the coolant flow in a Thermosyphon system?

a) Engine-Header tank –Radiator-Collector tank

b) Collector tank- Header tank-Radiator- Engine

c) Engine-collector tank- Header tank-Radiator

d) Radiator- Header tank- collector tank- Engine

Answer: a

Explanation: The coolant absorbs the heat from the engine and with the hose pipe flows to the header tank and then loses all of the heat in the radiator and then moves to the collector tank where the coolant is collected.

5. The main difference between the Pump circulation System and Thermosyphon System is the presence of ______

a) fan

b) radiator

c) hosepipe

d) pump

Answer: d

Explanation: The Pump is used along with the Thermostat where the Pump is used for the circulation of coolant and the thermostat controls the flow of coolant.

6. For Better Thermal Conductivity ______and ______Alloys are used during the Manufacturing of Fins present in air-cooled Engines?

a) copper and Steel

b) brass and Copper

c) aluminum and Steel

d) bronze and Copper

Answer: a

Explanation: The Thermal Conductivity for Copper and Steel is 388.0W/m-C and the density is 8.933×10power3 kilogram per meter cube which is the highest when compared to other metals and their alloys.

7. In a Thermosyphon System, the rate at which the water circulates is _____

a) proportional to Load and Not to Engine speed

b) not Proportional to Load and Proportional to Engine Speed

c) proportional to Load and Proportional to Engine Speed

d) not Proportional to load and Not Proportional to Engine Speed

Answer: a

Explanation: As the amount of heat generated and cooling rate is maintained by natural convection due to which it is proportional to load and not on the engine speed.

8. The 12v DC Fan present in the Pump Circulation System is operated by_____ Sensor.

a) mass airflow

b) throttle Position Sensor

c) engine Coolant Sensor

d) steering Angle Sensor

Answer: c

Explanation: The Coolant Temperature Sensor  can be found along with the Thermostat which sends the real-time readings to the ECU and based on the Program the Fan is operated.

9. _____ Type of Wear takes places in the water Jackets of water-cooled engines?

a) mechanical

b) adhesion

c) abrasion

d) corrosion

Answer: d

Explanation: Corrosion Wear takes place as the water changes its state from liquid to gas the water droplets tend to remain in the jackets and in the presence of oxygen the corrosion attack takes place.

10. The position of the cooling Fan is_____ of the Radiator?

a) behind

b) top

c) bottom

d) in front

Answer: a

Explanation: The position of the fan is behind the Radiator and in front of the Engine wherein the fan sends the cold air and then cools the fluid present in the Radiator.

11. Which of the following is absent in the air-Cooled Engine?

a) Radiator

b) Fins

c) Inlet and Exhaust port

d) Cylinder Head

Answer: a

Explanation: The radiator is absent in these types because of which the air-cooled method is light in weight and applicable for two-wheelers as well.

12. For the proper maintenance _____number of years is recommended for the Flush of the Cooling System?

a) 5

b) 3

c) 2

d) 1

Answer: c

Explanation: The cooling system Flush keeps the engine running smooth and cool even on the hottest days. The cooling system flush is recommended every two years or every 24,000 to 36,000 miles to remove any rust or contaminants.

13. According to the maintenance which of the following is true?

a) Air cooling is easier

b) Water cooling is easier

c) Both water and air are easier

d) Oil cooling

Answer: a

Explanation: Air cooling is easier and there are no problems like leakage of coolant or fluid as it is absent in the air colling system and the absence of hose pipe results in fewer components to maintain during vehicle service.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Components of Water Cooling System”.

1. In a Tubular Type Radiator Core the tubes are made in the range of ______to_____ sheet.

a) 0.1 to 0.3

b) 0.5 to 0.7

c) 0.2 to 0.4

d) 0.3 to 0.5

Answer: a

Explanation: The core tubes are made from the thinnest possible material. Tubes are made from 0.1mm to 0.3 mm sheet; the fins are made about 0.1 mm thick material.

2. For Heavy Duty Application Radiator ______ is automatically controlled through the compressed air taken from the brake system.

a) spring

b) shutter

c) gasket

d) tank

Answer: b

Explanation: The shutter remains closed during the starting and it gradually opens up as the engine attains its working temperature, thus allowing the fresh air to come into contact with the radiator.

3. To maintain the coolant at a higher pressure than the atmosphere ______ are provided in the Radiator.

a) fins

b) radiator cap

c) blow-off valve

d) overflow pipe

Answer: b

Explanation: The pressure cap forms an airtight joint due to which the coolant is maintained at some higher pressure than the atmosphere due to which the boiling point of the coolant is raised.

4. ______ valves Operates to avoid the collapse of the radiator.

a) pressure

b) inlet

c) outlet

d) vacuum

Answer: d

Explanation: When the vacuum is created inside the vacuum valves operates and stops the collapse it usually operates when the vacuum exceeds about 5Kpa.

5. ______ Reservoir is provided to provide excess coolant as the engine temperature increases.

a) filler Neck

b) blow off

c) expansion

d) compression

Answer: c

Explanation: Expansion reservoir is connected to the radiator in such a way that it receives the excess coolant as the engine temperature increases. When the cooling water cools down, its volume decreases, and the coolant in the reservoir returns to the radiator keeping the system full of coolant.

6. ______ is used to keep the cooling water automatically to a predetermined value.

a) motor

b) overhead valve

c) overflow pipe

d) thermostat

Answer: d

Explanation: A thermostat is used to automatically keep the cooling water temperature at a predetermined value. It also helps the engine to reach the operating temperature as soon as possible after starting the engine.

7. In Bellows type thermostat the valve movement depends upon the difference between _____

a) temperature

b) vapor pressure

c) velocity

d) discharge

Answer: b

Explanation: The valve movement depends upon the difference between the Vapour pressure at any given temperature and the cooling pressure.

8. The pump mounted at the front end of the engine is driven from the ______by means of V-belt.

a) camshaft

b) crankshaft

c) motor

d) electric Pulley

Answer: b

Explanation: The coolant pump is a necessity for the forced circulation type of engine cooling system. The pump is mounted at the front end is driven from the crankshaft using V-belt. Centrifugal type pump is the one that is used for this purpose.

9. The core material used in the preparation of the radiator core is ______

a) brass

b) steel

c) plastic

d) cast iron

Answer: a

Explanation: The material used for radiator should be resistant to corrosion, possess higher thermal conductivity and form easily, apart from having adequate strength. Brass is the material used in the core preparation of the radiator core. Aluminum is also used for weight and cost considerations.

10. In Siemens VDO’s Smart coolant pump the pump is operated by the means of ______

a) 12v DC Motor

b) camshaft

c) crankshaft

d) mechanically

Answer: a

Explanation: The pump works on a 12v DC motor which can be controlled by the engine management system so that precise temperature can be maintained.

11. For the reduction of noise, the blades are spaced ______ sometimes.

a) evenly

b) unevenly

c) clockwise

d) anti-Clockwise

Answer: b

Explanation: Fan blades maybe four to seven blades that are spaced unevenly so that there is a reduction in the noise which is created. It is generally made of sheet metal, but these days molded plastic material or polypropylene are also being used for making fans.

12. The material used in the manufacturing of Fans in the cooling system is ______

a) cast iron

b) brass

c) plastic

d) bronze

Answer: c

Explanation: Plastic due to its lightweight advantage and it has no corrosive nature, the manufacturing cost of the plastic fan is less when compared to other material, it is also less in weight due to all these reasons plastic is preferred.

13. The Fans consumes around ______% of the engine BP If not operated efficiently and economically.

a) 11

b) 5

c) 6

d) 10

Answer: b

Explanation: The fan is the only part that is always running when the engine runs. The fab consumes as much as 5% of the engine BP and producing more noise. In modern cars, the fan blades are made with variable pitch type, which may speed-sensitive or temperature-sensitive type.

This set of Automotive Engine Auxiliary Systems online test focuses on “Coolants”.

1. The additives which are added to lower the Freezing point of the coolant is ______

a) anti- Knocking Agent

b) temperature controller

c) anti freezer

d) isomers

Answer: c

Explanation: The Anti-Freezer additive lowers the freezing point of water which helps when the temperatures fall very low. Even for hot climates, the use of antifreeze has the incidental advantage that the boiling point of the cooling water is raised.

2. The ratio of Ethylene glycol and Water in the coolant is ______

a) 50:50

b) 10:90

c) 30:70

d) 20:80

Answer: a

Explanation: Ethylene glycol keeps hoses and seals smooth and raises the coolant’s boiling point. The ratio of Ethylene glycol in water is 50:50 as it must be in balance for the evaporation of water when the engine temperature increases.

3. The qualities of the Anti-freezer must have these Qualities ______

a) average Viscosity

b) no corrosive property

c) must be Miscible

d) all of the above

Answer: d

Explanation: The coolant must be Miscible with water and should not be Corrosive when the coolant flows through the jackets and should have average viscosity.

4. Carboxylates are added in the Coolant to prevent from ______

a) freezing

b) condensation

c) evaporation

d) corrosion

Answer: d

Explanation: Carboxylate inhibitors provide corrosion protection by chemically interacting with the metal surfaces where needed, not by universally laying down layers.

5. ______ Meter is used to measure the Glycol and water ratio present in the coolant?

a) hydrometer

b) refractometer

c) galvanometer

d) voltmeter

Answer: b

Explanation: Refractometer is used to measure the glycol water ratio because it offers the best method to identify the precise glycol content of the coolant.

6. The pH range of Coolant is ______

a) equal to or Greater than 7

b) 0

c) 0-5

d) 3-6

Answer: a

Explanation: pH is a scale used to find how acidic or basic a given solution is. Acidic solutions have a lower pH, while basic solutions have a higher pH. Coolant operates in neutral or basic conditions as they should not react with the metals they travel through. So equal to or greater than 7 is preferred.

7. The coolant is made up of three components they are ______

a) water, anti-freezer and SCA’s

b) water, fuel, and silicates

c) water, buffers and SCA’s

d) water, SCA’s and defoamers

Answer: a

Explanation: The coolant consists of water and anti-freeze in proper proportion with a small amount of SCA’s. The antifreeze does not let the coolant to freeze in cold climates and the SCA’s helps in the life and health of the engine, especially older equipment.

8. The boiling point of ethylene glycol used in the coolant is ______Degree Centigrade

a) 290

b) 195

c) 200

d) 300

Answer: b

Explanation: The boiling point is the temperature at which the vapor pressure of a chemical equals atmospheric pressure. The boiling point of ethylene glycol is 195-degree Centigrade and used as coolant in automobiles. The higher boiling point indicates greater intermolecular force therefore less vapor pressure.

9. In a 50% concentration of ethylene glycol  lowers the freezing point of water to ______Degree Centigrade.

a) -30

b) -50

c) -35

d) -37

Answer: d

Explanation: Ethylene glycol interferes with the hydrogen bonding network in pure water. Water freezes at 0°C and pure ethylene glycol at -12°C, due to which 50% concentration of ethylene glycol lowers the freezing point of water to -37 degrees centigrade.

10. The coolant used in heavy-duty engines should be______

a) green in color

b) fully formulated

c) concentrated

d) blue

Answer: b

Explanation: The Coolant for a heavy-duty engine will be fully formulated adopts a propylene glycol and ethylene glycol as the basic liquid.

11. The abbreviation of SCA is ______

a) supplemental Coolant Additive

b) super Cooling Additive

c) standard Coolant Additive

d) strategic Chemical Additive

Answer: a

Explanation: SCA is vital for the health and longevity of any diesel engine and its abbreviation is supplemental Coolant Additive. The advantages of SCA is it extends the life and health of the engine, especially older equipment, and also aid in preventing cavitation and pitting in diesel engines.

12. The boiling point of the coolant should be ______

a) low

b) high

c) medium

d) none of the above

Answer: b

Explanation: The boiling point of them should be high thereby minimum loss due to evaporation and the coolant can be operated at the higher temperature.

13. The anti-freeze should have ______specific heat capacity to be compared to the specific heat capacity of the coolant.

a) zero

b) average

c) low

d) high

Answer: d

Explanation: The anti freezer plays a critical role in sustaining engine heat balance by removing heat. The main requirement of an anti-freeze is that it should have a high specific heat capacity when compared to that of the coolant.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Testing of Lubricants”

1. ______ apparatus is used in the determination of Flash and Fire point of a lubricating oil.

a) saybolt

b) engler

c) able’s

d) redwood

Answer: c

Explanation: Flashpoint is the minimum temperature at which it gives vapor which is sufficient to form an explosive mixture with air. The fire point is the further heating to a stage where it starts to burn continuously on applying flame to it. Both are determined by Abel’s apparatus.

2. ______ apparatus is used in the determination of loss due to Evaporation of the lubricating oil.

a) able’s

b) engler

c) arch butt

d) hydrometer

Answer: c

Explanation: When the lubricating oil is subjected to high temperatures, they are liable to vaporize to a certain extent. Loss due to evaporation of the lubricating oil is determined by the Arch butt method.

3. ______ is the temperature at which lubricating oil ceases to flow when cooled at standard condition.

a) flashpoint

b) fire point

c) moisture test

d) pour point

Answer: d

Explanation: The pour point is the temperature at which a lubricant just ceases to flow when cooled under standard conditions. The lower the pour point the better is the lubricant.

4. The acid value of an oil is the number of milligrams of ______ used to neutralize 1gram of oil.

a) sodium hydroxide

b) potassium hydroxide

c) sulfur dioxide

d) ester

Answer: b

Explanation: Acid value of an oil is the number of milligrams of potassium hydroxide required to neutralize 1gram of oil. To determine the acid value, about 5-10 grams of the oil is taken in a conical flask. About 40-50 c.c of neutral alcohol is added in the flask.

5. Saponification value of an oil is the number of milligrams of potassium hydroxide required to saponify completely ______ grams of the oil.

a) 10

b) 1

c) 1000

d) 100

Answer: b

Explanation: The saponification value of an oil is the number of milligrams of potassium hydroxide required to saponify completely one gram of the oil. Saponification is a process involved with soaps and oils.

6. Determination of saponification value helps in the detection of ______

a) acid

b) base

c) salt

d) adulteration

Answer: d

Explanation: Saponification value refers to the small amounts of compounds containing oxygen, which are not removed during the refining process and this value also helps in the detection of adulteration.

7. One liter of normal potassium hydroxide contains ______grams of potassium hydroxide.

a) 65

b) 67

c) 56

d) 59

Answer: c

Explanation: 1 mole of potassium hydroxide is equal to 56.10564 grams. Hence, One liter of normal potassium hydroxide contains 56 grams of potassium hydroxide.

8. Emulsion is a mixture of ______and ______when mixed thoroughly.

a) lubricating oil and acid

b) water and acid

c) lubricating oil and water

d) lubricating oil and base

Answer: c

Explanation: When lubricating oil mixes thoroughly with water, an intermediate mixture of the two knows as an emulsion. The lesser the emulsification tendency, the better the oil is. A good lubricant should be such that the emulsion is formed, should break off quickly.

9. Insoluble residue test is used to determine______

a) additives

b) insoluble particles

c) pour point

d) fire point

Answer: b

Explanation: A known weight of the lubricating oil is dissolved in spirit .the solution is filtered and the residue is washed with pure solvent, dried, and weighed. From this percentage of insoluble residue in the oil is calculated.

10. The tendency to de-emulsify quantitatively is determined by ______test.

a) hydrometer

b) A.S.T.M emulsion

c) centistokes

d) centipoises

Answer: b

Explanation: The tendency to de-emulsify is quantitatively determined by the A.S.T.M emulsion test. In this, 20ml of oil is taken in the test tube and steam at 100 degrees centigrade is bubbled through it, till the temperature is raised to 90 degrees centigrade.

11. The time required for the constituents to separate from the emulsion is known as ______

a) saponification number

b) emulsion number

c) Archimedes principle

d) acid value test

Answer: b

Explanation: The time in seconds required for the constituents to separate from the emulsion is known as steam emulsion number. A good lubricant should possess a low emulsion number. The quicker the oil separates from the emulsion, the lower is the steam emulsion number and for most purposes the oil is suitable.

12. Specific gravity is determined by ______ test.

a) Archimedes principle

b) acid value test

c) emulsification test

d) insoluble residue test

Answer: a

Explanation: Archimedes’ principle is the most accurate way to determine the specific gravity of the lubricating oil. Archimedes principle states that the buoyant force on an object equals the weight of the fluid it displaces. Specific gravity is the ratio of the density of unknown oil to the density of water.

13. ______ is used to find the viscosity of the lubricating oil.

a) loss due to evaporation

b) viscometer

c) moisture test

d) None

Answer: a

Explanation: Viscosity is the friction between two surfaces of the liquid. Viscometer is used to determine the viscosity of the lubricating oil. The viscometer is based on the principle that a viscous liquid resist flow, exhibiting a decreasing pressure along the length of the slit.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Systems of Engine Lubrication”.

1. For a two-stroke engine ______ system of engine lubrication is used.

a) pressure system

b) petroil system

c) splash system

d) dry-sump system

Answer: a

Explanation: In a two-stroke engine petroil system is used in which the oil is added with the fuel into the tank. The fuel evaporates leaving behind the oil and lubricating the moving parts.

2. The average range of oil mixed with petrol in a two-stroke engine ______

a) 2%to3%

b) 4%to6%

c) 3%to7%

d) 2%to8%

Answer: a

Explanation: The ratio of lubricating oil to petrol is in the range of 2%to3%. Hence, the average range of oil mixed with petrol in a two-stroke engine is 2%to3%.

3. ______ is connected to the connecting rod in splash type of lubrication.

a) fork

b) scoop

c) bearing

d) none of the above

Answer: b

Explanation: Scoop is attached to the connecting rod were in the scoop tales few of the oil from the oil sump and splashes into the camber. Scoop is an extended part the resembles like a spoon.

4. ______ is attached to the oil pump in the pressure system to guard it against the entry of grit.

a) oil pan

b) strainer

c) oil pump

d) pressure gauge

Answer: b

Explanation: The strainer is connected just below the oil pump the oil is sucked in from the strainer. This guards the pump against the entry of grit. The strainer has mesh to filter the oil and grits.

5. ______ valve is provided to control the oil pressure of the lubricating oil.

a) pressure-relief

b) control

c) directional control

d) flow control

Answer: a

Explanation: Pressure relief valve is provided to control the oil pressure of the lubricating oil. It protects during an overpressure event. The pressure relief valve is situated in the filter unit or the pump housing.

6. The pressure range developed in the pressure system engine lubrication is ______ kpa.

a) 200-400

b) 0-100

c) 0-50

d) 30-60

Answer: a

Explanation: In a pressure system, an oil pump takes oil from the wet will through a strainer and delivers it through a filter to the main oil gallery. Pressure range developed in the pressure system engine lubrication is 200-400kpa.

7. In race cars ______ type of lubrication system is used.

a) pressure system

b) splash system

c) petrol system

d) dry-sump system

Answer: d

Explanation: The system used in race cars is the dry-sump system wherein two pumps are used which makes it more complex and costlier. The scavenge pump is installed in the crankcase portion. Whereas the pressure pump pumps the oil through the filter to cylinder bearings.

8. The pressure range maintained in a dry-sump system is ______ kpa.

a) 290-390

b) 195-290

c) 200-400

d) 400-500

Answer: d

Explanation: The pressure range maintained in the dry-sump system 400-500kpa. This pressure lubricates the engine components firmly. The pressure is generally measured in Kpa instead of the bar.

9. The oil cooler is present in ______ type of lubricating system.

a) pressure lubricating system

b) dry-sump system

c) splash system

d) petroil system

Answer: a

Explanation: In heavy-duty engines during the oil circulation, the oil gains heat from various engine parts, which is given out to the sump walls due to which separate oil cooler is used to cool the oil so that lubrication efficiency is increased.

10. ______ hole is made from big end to small end in the sank for lubrication.

a) rifle

b) punch

c) gudgeon pin

d) none of the above

Answer: a

Explanation: A rifle hole is drilled from the small end to the big end of the connecting rod through which the lubricating oil flows. This oil present in the small end gains heat from the piston and reaches the big end of the connecting rod and mixes with the oil present in the oil sump.

11. In the dashboard, the warning light comes ON when the pressure of the lubricating oil falls below ______ value.

a) 0.3

b) 0.4

c) 0.2

d) 0.5

Answer: a

Explanation: At the end of the main oil gallery, and oil-pressure switch is provided which operates the warning light on the dashboard. When the oil pressure becomes lower than the specified value 0.3 bar, the warning lights come on, to attract the driver’s attention.

12. The dry sump is not preferred in the small vehicle due to ______

a) complex

b) costlier

c) high-pressure oil lines

d) all of the above

Answer: d

Explanation: The dry-sump is more reliable, but is more complex and costlier due to additional pump and high-pressure oil lines due to which it is not used for small vehicles.

13. The oil pressure used in lubricating the camshaft is ______ kpa.

a) 0-20

b) 20-40

c) 0-50

d) 50-100

Answer: d

Explanation: The oil pressure is maintained at 400-500kpa for the main and big-end bearing while about 50-100kpa pressure is used for timing gears and camshaft bearing.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Lubrication and Lubricants – Oil Pumps”.

1. Which among the following helps in the increase in the oil pressure in an engine?

a) Engine speed

b) Coolant flow

c) Clearance

d) Engine temperature

Answer: a

Explanation: The Oil Pressure in the engine increases with the increase in engine speed which would increase the working speed of the oil pump.

2. What is the direction of rotation of a driven gear in a gear pump if the driving gear rotates in an anticlockwise direction?

a) Clockwise

b) Anticlockwise

c) Has no effect

d) Rotates on its own

Answer: a

Explanation: Both the gears are meshed due to which the driving gear rotates anticlockwise and the driven gear rotates in the clockwise direction in a gear-driven gear pump.

3. How are the axes of rotation of two rotors present in a rotor pump?

a) Same

b) Different

c) Do not depend on each other

d) Has no effect

Answer: b

Explanation: The axes of rotation of the two rotors are different which causes the size of the spaces between them to vary.One of the rotors gets its drive from an engine which causes the other rotor to rotate along with it.

4. Which is the force acting on the vanes due to which the vanes are pressed outwards against the housing?

a) Centrifugal

b) Tension

c) Frictional

d) Air resistance

Answer: a

Explanation: When the vane pump operates, the vanes are pressed outwards against the housing by the centrifugal force. The oil enters the inlet port and is swept by the vanes to the outlet port.

5. How do the outer and inner gear mesh in a Crescent type gear pump?

a) Externally

b) Internally

c) Both Externally and Internally

d) Do not mesh with each other

Answer: b

Explanation: Crescent type gear pump the outer Gear and the inner gear is in mesh internally due to this space which is of a crescent shape hence the name.

6. How is the number of lobes on the outer rotor when compared to the inner rotor lobes in a rotor pump?

a) Less

b) More

c) Same

d) Has no effect

Answer: a

Explanation: In the rotor pump the outer rotor always has 1 less lobe when compared to the inner rotor wherein the extra space the oil gets compressed.

7. The plunger pump is an example of which type of pump?

a) Rotary

b) Reciprocating

c) Radial

d) Centrifugal

Answer: b

Explanation: Plunger pump is a reciprocating type of pump in which the oil gets communicated from the inlet to the outlet by alternate suction and pressure created by a reciprocating plunger.

8. How is the oil flow in a vane-type pump?

a) Continuous

b) Dis-continuous

c) Turbulent

d) Laminar

Answer: a

Explanation: The vane-type pump there is an advantage of a continuous oil flow compared to the pulsating oil flow in case of the gear pump.

9. What is the range of pressure oil with which the gear pump delivers?

a) 0-100KPa

b) 100-200KPa

c) 200-300KPa

d) 300-400KPa

Answer: d

Explanation: The gear pump is always submerged in oil and the pump delivers oil at about 300-400KPa. Hence 300-400KPa is the range of oil pressure.

10. How should be the bearing clearance for higher oil Pressure?

a) More

b) Less

c) Zero

d) Does not affect oil pressure

Answer: b

Explanation: The lesser clearance would mean higher oil pressure delivered at the outlet.Any restriction in the lubrication passages would also increase the oil pressure.

11. What is the use of the Spring ball valve in a gear pump?

a) To know the temperature

b) To cutoff the rotation of the gears

c) To know the pressure level

d) None of the mentioned

Answer: c

Explanation: When the pressure exceeds the prescribed value, the spring is compressed and the ball is lifted off its seat and the oil passes back to the inlet side through the bypass provided.

12. How much more is the efficiency of the Rotor pump when compared to the gear type?

a) 5%

b) 10%

c) 20%

d) 25%

Answer: d

Explanation: The Rotor type pump is about 25% more efficient and compact than the gear type pump. So, they are used very widely in automobiles.

13. What is the name of the space that is formed between two gears due to eccentricity?

a) Crescent

b) Triangle

c) Rectangle

d) Circle

Answer: a

Explanation: Due to eccentricity, there is a space in between two gears where the crescent space is placed. The crescent shape both offsets the idler gear and provides a seal between the suction and discharge ports.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Lubrication and Lubricants – Oil Filters”.

1. What is the size in the micrometer of the wire gauze present in a strainer?

a) 0-20

b) 20-40

c) 40-60

d) 60-80

Answer: c

Explanation: The strainer which is more commonly known as the primary filter is formed from wire gauze of 40-60 micrometers. The primary filter is also known as a surface filter since the impurities are retained on the outer surface of the filter.

2. How is the flow of whole oil concerning the filter in a by-pass system of oil filtration?

a) Passes the filter

b) Doesn’t pass the filter

c) Partially passes the filter

d) The oil flow is not related to the filter

Answer: b

Explanation: In the bypass system the whole oil doesn’t pass through the filter at the same time. Most of the oil without being filtered goes to the bearings whereas the rest passing through the filter is cleaned out and returned to the sump.

3. What is the pressure range in KPa at which the spring-loaded relief valve is incorporated in the filter which bypasses and an emergency supply of unfiltered oil to the bearings?

a) 0-40

b) 40-100

c) 100-300

d) 400-800

Answer: b

Explanation: The spring-loaded relief valve is incorporated in the filter, which bypasses an emergency supply of unfiltered oil to the bearing to avoid bearing starvation is designed to open at 40 to 100kPa.

4. Which of the following is not a good characteristic of an oil filter?

a) High filtration efficiency

b) Long life

c) Less pressure loss

d) Dirty exhaust fumes

Answer: d

Explanation: A oil filter should have high filtration efficiency and less pressure loss.excessive pressure loss occurs due to high resistance in the filter element, preventing oil from reaching all the engine parts and it should have a long life and it should not produce any dirty exhaust fumes.

5. On which side of the oil pump is the surface filter installed?

a) Inlet

b) Outlet

c) Transfer

d) Intermediate

Answer: a

Explanation: The surface filter is installed on the inlet side of the oil pump.Whereas the secondary filter is installed on the outlet side of the oil pump and since the impurities in this are retained progressively along with the depth of the filter material, it is also called depth filter.

6. Which of the following is also known as Edge type oil filter?

a) Stack

b) Plunger

c) Barrel

d) Piston

Answer: a

Explanation: Edge type oil filter is also known as a stack type. In this type, the oil is made to pass through several closely spaced discs. These alternate discs are mounted over a central spindle, while the discs in between these are attached to a separate fixed spindle.

7. What is the resistance to flow in the range of bar offered by a new filter element?

a) 0-0.1

b) 0.1-0.3

c) 0.3-0.5

d) 0.5-0.7

Answer: c

Explanation: The resistance to flow offered by a new filter element is about 0.3-0.5 bar. However, with the use, the resistance increases due to clogging of the filter element as the time passes by due to accumulation of dirt and other impurities.

8. Which among the following is provided in an edge type oil filter to remove the impurities periodically?

a) Central knob

b) Adjusting screw

c) Relief valve

d) Pilot jet

Answer: a

Explanation: The oil is made to flow through the space between these discs and because of the very small spaces involved the impurities are left on the disc peripheries from where these are periodically removed by the simply operating central knob.

9. Which is the most commonly used material for filtering in cartridge type oil filter?

a) Wire gauze

b) Copper

c) Cobalt

d) Zinc

Answer: a

Explanation: The commonly used material for filtering is wire gauze, cotton, paper, etc. The filtering element must let the oil pass through without much resistance, but should prevent the undesirable particles from entering the oil galleries.

10. In what range is the accumulation of impurities increased concerning the operating time in an unfiltered system?

a) Not proportion

b) Proportional

c) Doesn’t depend

d) Has no effect

Answer: b

Explanation: In an unfiltered system, the accumulated impurities increase in direct proportion to the operating time. As time passes by the impurities get accumulated due to which a regular service of the filtering system is required.

11. Which of the following is connected to a knob that operated manually helps in removing impurities on the disc peripheries in an edge type oil filter?

a) Brake

b) Clutch

c) Accelerator

d) Shaft

Answer: b

Explanation: The knob can be manually operated as it is connected to the clutch system and operated periodically using clutch action. By this system, all the impurities are removed from an edge type of oil filter.

12. What is the range of maximum permissible resistance in a bar in a cartridge type oil filter?

a) 0

b) 1

c) 2

d) 5

Answer: c

Explanation: The resistance increases due to clogging of the filter element .the maximum permissible resistance is about 2 bars. The cartridge type is the most used in automobile engines.

13. What is the speed range of the rotor is usually in rpm in a centrifugal type oil filter?

a) 0-1000

b) 1000-2000

c) 2000-7000

d) 7000-10000

Answer: c

Explanation: The working speed of the rotor in a centrifugal type oil filter is in the range of 2000-7000 rpm, depending upon the oil pressure circulating the oil. Force up to 2000 times the gravity is produced which are quite effective in throwing the impurities.

This set of Automotive Engine Auxiliary Systems online quiz focuses on “Petrol Engine Fuel Supply System – Fuel Pumps”.

1. Which material is used for the valves of the A.C mechanical pump?

a) Cast iron

b) Plastic

c) Bakelite

d) Paper

Answer: c

Explanation: The A.C pump’s valves are made up of Bakelite, which being lighter keeps the inertia stresses minimum and they are resistant to heat, scratches, and destructive solvents which makes it be most commonly used.

2. What is the pressure range in kPa in the petrol pipeline between the fuel pump and the carburetor?

a) 5-10

b) 10-20

c) 20-35

d) 35-40

Answer: c

Explanation: The pressure in the petrol pipeline between the fuel pump and the carburetor, is kept under the pressure between about 20 and 35kPa, the exact pressure range being determined by the stiffness of the diaphragm return spring.

3. Which of the following provides the force to drive the pump?

a) Crankshaft

b) Differential

c) Camshaft

d) V-belt

Answer: c

Explanation: The driving force the pump is taken from camshaft by the means of eccentric or cam. The eccentric cam operates the rocker arm which is in conjunction with the diaphragm return spring pushes the diaphragm up and down.

4. Which of the following helps in the relief of the excess pressure which is built up?

a) Pull rod

b) Diaphragm return spring

c) Camshaft

d) Suction valve

Answer: b

Explanation: The pump will build up excessive pressure which may damage the pump itself. This is taken care of by the diaphragm return spring which remains partially or fully compressed depending upon the line pressure.

5. Which material is used in the diaphragm of an A.C mechanical pump?.

a) Paper

b) Metal sheet

c) High-grade cotton and rubber

d) Ceramic

Answer: c

Explanation: The diaphragm used in the A.C mechanical pump is made out of high-grade cotton impregnated with synthetic rubber. The downward movement of the diaphragm causes a vacuum in the chamber which causes the inlet valve to open.

6. Which type of energy is used to operate the diaphragm in an S U electrical pump?

a) Mechanical

b) Hydraulic

c) Electrical

d) Solar

Answer: c

Explanation: Alternate vacuum and pressure are produced due to movement of the diaphragm which is caused electrically in the S U electrical pump. Closing the ignition switch energies the solenoid winding, magnetic flux is generated which pulls the armature to which diaphragm is attached.

7. Which of the following is the correct sequence of fuel travel?

a) Tank – fuel pump – fuel filter – carburetor

b) Tank – fuel filter – fuel pump – carburetor

c) Fuel filter – fuel pump – tank – carburetor

d) Carburetor – fuel pump – fuel filter – tank

Answer: a

Explanation: The fuel flows from the fuel tank to the fuel pump where the fuel is pumped to high pressure and then the high-pressure fuel enters the filter and the dust and retained in the filtered and then the fuel is sent into the carburetor.

8. Which valve opens when the downward movement of the diaphragm causes a vacuum in the chamber?

a) Outlet

b) Inlet

c) Both outlet and inlet

d) Transfer

Answer: b

Explanation: The Downward movement of the diaphragm causes a vacuum in the chamber which causes the inlet valve to open. This vacuum helps in the suction of the oil and is one of the most important processes in pump operation.

9. Which system experiences Vapour locking in the fuel system?

a) A.C mechanical pump

b) S U electrical pump

c) Both A.C mechanical pump and S U electrical pump

d) Electrical pump

Answer: a

Explanation: Since the A-C pump is situated close to the engine due to which they are exposed to engine heat, which may result in vapor locking in the fuel system. Which is taken care of by the diaphragm return spring.

10. Which of the following component movement interrupts the electrical supply by disconnecting the breaker points?

a) Float chamber

b) Diaphragm

c) Strainer

d) Armature

Answer: d

Explanation: The armature moves, it interrupts the electric supply by disconnecting the breaker points. Due to which the solenoid is de-energized and the armature falls back, causing the diaphragm to move to create pressure in the pump chamber.

11. Which of the following has the requirement of placing the pump necessarily close to the engine ?

a) A.C mechanical pump

b) S U electrical pump

c) A.C mechanical pump & S U electrical pump

d) Electric pump

Answer: a

Explanation: The pump need notbe situated close to the engine in S U electrical pump therefore in the A.C mechanical type the pump needs to be situated close to the engine thus they are subjected to engine heat.

12. In which system the pump starts to operate immediately as the ignition is switched on?

a) A.C mechanical pump

b) S U electrical pump

c) A.C mechanical pump & S U electrical pump

d) Mechanical pump

Answer: b

Explanation: In an S U electrical pump the electric pump needs not to wait for the engine to start. It starts to operate immediately as the ignition is switched on. Whereas the A-C mechanical pump does not have this advantage.

13. Which property of the diaphragm return spring helps in the determination of the exact pressure range?

a) Tension

b) Stress

c) Starin

d) Stiffness

Answer: d

Explanation: The exact pressure range being determined by the stiffness of the diaphragm return spring. The controlled pressure in the petrol supply line is very important to be maintained. If the pressure is low, the petrol supply will not be able to keep pace with the demand under high speed or high load conditions.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Petrol Engine Fuel Supply System – Air Cleaners”.

1. Which among the following is a function of air cleaner when the engine back-fires?

a) Flame arrester

b) Diffuser

c) Flame arrester and Diffuser

d) Pressure reliever

Answer: a

Explanation: The Engine backfires, the air cleaner also acts as a flame arrester. However, resistance to the airflow which is increased as the air cleaner gets clogged with due to which the engine performance would get decreased.

2. Which among the following is a function of an air cleaner concerning the carburation system?

a) Reducing agent

b) Catalyst

c) Silencer

d) Ventilation

Answer: c

Explanation: The air cleaner acts as a silencer for the carburation system as it reduces the engine induction noise to an acceptable level. The air cleaner is the most important part as hundreds of cubic meters of air per hour are used by the engine of an automobile.

3. Which part of the engine does not rapidly wear due to impurities like dust?

a) Cylinder

b) Pistons

c) Rings

d) Camshaft

Answer: d

Explanation: The impurities like dust in the air cause very rapid wear of the engine, particularly the cylinder, piston, rings, valves, and guides. Whereas the camshaft is not part of the cylinder as the camshaft just helps in the valve timing.

4. When an air cleaner gets clogged with dirt. How are the airflow,Engine performance, and fuel consumption respectively?

a) Increase, sluggish, lower

b) Decrease, sluggish,higher

c) Increase, better, lower

d) Has no effect

Answer: b

Explanation: When the air cleaner gets clogged the airflow gets decreased, resulting in sluggish engine performance and higher consumption of fuel. Therefore, it should be cleaned regularly or replaced periodically for every 20,000kms.

5. Which among the following is an example ofan oil bath type air filter?

a) Thermostatic control of air cleaner

b) Light duty types of air cleaner

c) Heavy-duty type air cleaner

d) Thermostatic control of air cleaner light duty types of air cleaner

Answer: c

Explanation: Heavy-duty type air cleaner is also known as an oil bath type wherein the filter is saturated with oil. The air from the atmosphere enters through the circumferential gap and around the corner the air takes a turn and large particle impurities are left.

6. In which type of air filter at idling or cold start condition the incoming air is heated and then sent to the cleaner?

a) Heavy-duty type air cleaner

b) Light duty type air cleaner

c) Thermostatic control of air cleaner

d) Heavy-duty type air cleaner and Light duty type air cleaner

Answer: c

Explanation: In the modern engine the lean fuel-air is used to reduce the pollution due to which efficiency decreases, therefore, to remedy this the incoming air is heated and then sent to the air cleaner.

7. At what temperature in degree centigrade such that the bleed valve opening is maximum when the hot air supply is cut-off?

a) 10

b) 20

c) 30

d) 40

Answer: d

Explanation: At 40-degree Centigrade, the bleed valve opening is maximum when the hot air supply is cutoff and only outside air enters the carburetor. This is provided in modern engines to reduce air pollution.

8. Which material is used as a cleaning element in a light-duty type air cleaner?

a) Plastic

b) Metal

c) Cellulose

d) Both Plastic and metal

Answer: c

Explanation: The cleaning element consists of a cylindrical cellulose fiber material, over which is put a fine mesh screen to provide strength. The element is corrugated to increase the surface area exposed to the incoming air.

9. To increase which of the following the cleaning element is corrugated and exposed to the incoming air?

a) Temperature

b) Pressure

c) Surface area

d) Force

Answer: c

Explanation: The element is corrugated to increase the surface area exposed to the incoming air so that the resistance offered by the cleaner is reduced to a minimum. Sides of the element are sealed against dust. The air passes through the element and any dust contained is left outside.

10. In which type of air cleaner the filter element is saturated with oil?

a) thermostatic control of air cleaner

b) light dusty type air cleaner

c) heavy-duty type air cleaner

d) both thermostatic and light dusty type

Answer: c

Explanation: The heavy-duty type air cleaner is also called an oil bath type wherein the filter material is saturated with oil. Impinging on the surface of the oil relieves the air further of the impurities. The final cleaning is done by a filter and clean air is passed to the engine.

11. Which among the following is the correct air movement in a heavy-duty type air cleaner?

a) Inlet – circumferential gap – oil bath – filter

b) Inlet – filter – oil both – the circumferential gap

c) Inlet -oil bath – filter – the circumferential gap

d) Circumferential gap- inlet -oil bath – filter

Answer: a

Explanation: The flow of air starts through the inlet and passes through the circumferential gap where the airflow takes a turn and then the oil bath and the filter which is dipped in oil where the total impurities present in the air are removed.

12. Which among the following is used to mesh with the cleaning material in a light-duty type of air filter?

a) Mesh screen

b) Plastic

c) Polymer coating

d) Sheet metal

Answer: a

Explanation: The air cleaner consists of a cylindrical cellulose fiber material, over which is put a fine mesh screen to provide strength. The element is corrugated to increase the surface area exposed to the incoming air so that the resistance offered by the cleaner reduced to a minimum.

13. Which are the parts that get damaged when dirt enters the crankcase?

a) Heavy-duty type air cleaner

b) Light duty type air cleaner

c) Thermostatic control of air cleaner

d) Heavy-duty type air cleaner and Light duty type air cleaner

Answer: d

Explanation: If the dirty air enters the crankcase, it will contaminate the lubricating oil and ultimately damage the bearings and journals and decrease the service period of the lubrication system.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Petrol Engine Fuel Supply System – Simple Carburettor”.

1. Which of the following material is used to make the float of a carburetor?

a) Paper

b) Sheet metal

c) Nylon plastic

d) Cast iron

Answer: b

Explanation: The floats have a tendency to leak along the joint seams.due to which they are made of nylon plastic or expanded synthetic rubber. The needle valve attached to the float serves to close or open the fuel inlet to the float chamber depending on the requirements.

2. Which of the following is provided in the float chamber to keep the pressure inside atmospheric?

a) Float

b) Fuel jet

c) Small vent

d) Throttle valve

Answer: c

Explanation: A small vent in the float chamber keeps the pressure inside the atmospheric. In modern practice, it is preferred to vent the float chamber to the air intake of the carburetor. In modern practice, it is preferred to vent the float chamber to the air intake of the carburetor.

3. Which of the following increases with the reduction of area in a venturi?

a) Temperature

b) Velocity

c) Enthalpy

d) Entropy

Answer: b

Explanation: In the venturi the passage is is minimum. Thus due to less area, the air velocity increases and because of this increase in velocity, a decrease in pressure is caused at the nozzle which is located in venturi itself.

4. Which among the following does not affect the amount of fuel delivered?

a) Jet size

b) Float level

c) Venturi vacuum

d) Ignition timing

Answer: d

Explanation: The amount of fuel delivered depends upon the major factors like jet size, float level, and venturi vacuum. Whereas the ignition timing does not affect the amount of fuel that is being delivered to the engine via the carburetor.

5. What is the main function of a throttle valve?

a) Temperature

b) Air-fuel

c) Enthalpy

d) Entropy

Answer: b

Explanation: The purpose of a throttle valve is to control the quantity of the air-fuel mixture and it is attached to the accelerator pedal. Whereas there is no such great effect of the throttle valve in the factors like temperature, enthalpy, and entropy.

6. Which of the following component is used to maintain the liquid-tight seal during vibration?

a) Three-piece valve with rubber seat tip

b) Vent

c) Nozzle

d) Throttle valve

Answer: a

Explanation: A three-piece valve with a rubber seat tip and a spring-loaded ball In the body of the stem. Whereas the other components like the vent, nozzle and the throttle valve are the main parts of a carburetor which helps in the air-fuel mixture ratio.

7. What is the main function of a float in the float chamber?

a) Constant head of fuel

b) Ventilation

c) Temperature control

d) Enthalpy

Answer: a

Explanation: The fuel starts to flow in and the float rises gradually till the fuel level reaches the desired value. At this time, the float needle closes the fuel inlet passage. Thus a constant head of fuel is maintained in the float.

8. In practice what is the fuel level in the float chamber that is maintained in millimeter below the nozzle?

a) 10

b) 5

c) 20

d) 15

Answer: b

Explanation: The fuel level in the float chamber is maintained about 5mm below the nozzle outlet. A small vent in the float chamber keeps the pressure inside atmospheric and in modern practice is preferred to vent the float chamber to the air intake of the carburetor.

9. How is the fuel supply from the float chamber at any time is metered?

a) Float chamber

b) Fuel jet

c) Throttle valve

d) Nozzle

Answer: b

Explanation: The fuel supply from the float chamber at any time is metered by a means of the fuel jet from where the fuel flows to the venturi through the discharge nozzle. The venturi is simply a restriction in the air passage where the passage area is minimum.

10. What is the correct stoichiometric ratio for an air-fuel mixture?

a) 14.7:1

b) 14:1

c) 15:1

d) 9:1

Answer: a

Explanation: The stoichiometric ratio of air-fuel is 14.7:1. It means that 14.6 parts of air and 1 part of gasoline or petrol  is the one which would give chemically correct combustion of petrol under ideal conditions.

11. Which among the following is not a function of the carburetor?

a) A small reserve of fuel at constant head

b) To vaporize the fuel to prepare a homogeneous mixture

c) To supply the correct amount of air-fuel mixture

d) To delay the ignition timing depending in the exhaust gas

Answer: d

Explanation: The functions of a carburetor is to keep a small reserve of fuel at the constant head, vaporize the fuel to prepare a homogeneous air-fuel mixture, supply correct amount of the air-fuel mixture at the correct strength and the ECU takes care of the ignition timing depending on the input from the oxygen sensor.

12. For which operation is the Lean air-fuel mixture required?

a) Starting

b) Idling

c) Cruising

d) Acceleration

Answer: c

Explanation: During cruising the air-fuel mixture is lean as the emission is controlled by using this ratio. Where more air is burnt for the same value of the fuel when operating at sea level. These weaker mixtures provide a good economy when compared to the economy of the rich mixture.

13. Where is the throttle valve is attached to control the flow of air?

a) Clutch

b) Accelerator

c) Brake

d) Hand brake

Answer: b

Explanation: The throttle is directly connected to the accelerator pedal wherein depending on the accelerator pedal the amount of air and fuel required is sent inside the combustion chamber.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Petrol Engine Fuel Supply System – Carburettor Types”.

1. Which of the following is an example of a constant vacuum type carburetor?

a) Carter carburetor

b) Zenith

c) S U carburetor

d) Both Carter and Zenith

Answer: c

Explanation: The S U carburetor is a typical example of variable venturi or constant vacuum type of carburetor. There is both a vertical and horizontal model is being produced. The horizontal type has a spring-loaded piston to control the air passage.

2. Which of the following is an example of constant venturi type carburetor?

a) Zenith carburetor

b) Carter carburetor

c) S U carburetor

d) Both Zenith and Carter carburetor

Answer: d

Explanation: Carter and Zenith type carburetor are the two types of constant venturi. Whereas the S U carburetor is an example for a constant Vaccum type carburetor. Zenith carburetor is one of the most popular carburetors.

3. How many numbers of jets are present in a zenith type carburetor?

a) 4

b) 2

c) 3

d) 1

Answer: c

Explanation: There are three jets present In a zenith carburetor. The jets are the main jet, compensating jet and the idling jet. The main jet has an outer cover, the annular passage between the main jet and outer cover forms a delivery tube for the compensating jet.

4. Which of the following is a type of arrangement concerning Solex carburetor?

a) Up- drought

b) Horizontal

c) Down- drought

d) Both Up- droughtand Down- drought

Answer: c

Explanation: Solex carburetor is a down drought type of carburetor, with special provision for a progressive starter which supplies rich mixture for starting and then gradually weakens it till the engine has reached its operating temperature.

5. Which among the following is provided to avoid flat spot during acceleration and delivers spurts of extra fuel in a Solex carburetor?

a) Idle port

b) Membrane pump

c) Idle adjusting screw

d) Throttle

Answer: b

Explanation: To avoid flat spot during acceleration a separate membrane pump is provided which delivers spurts of extra needed fuel for acceleration. Pump lever is connected to the accelerator pedal so that when the same is pressed, the lever moves towards left, thus pressing the membrane towards the left and forcing petrol into the main jet.

6. Which of the following helps in the fuel flow when the choke is applied?

a) Main jet

b) Idle jet

c) Transfer port

d) Progression hole

Answer: a

Explanation: When the choke is applied the fuel is made to come out from the main jet and the fuel is delivered. The choke valve is closed, the whole of the engine suction is applied at the main nozzle, which then delivers fuel.

7. Which part of the idling circuit of a carter carburetor the engine suction is applied through which air and fuel are drawn?

a) Low-speed port

b) Main nozzle

c) Idle port

d) Metering rod

Answer: c

Explanation: For idling circuit, the throttle valve is almost closed and the whole engine suction is applied at the idle port, through which the air and the fuel are drawn giving rich mixture. This rich mixture requires more fuel for the proper combustion.

8. Where is the accelerator pedal connected in a full-throttle circuit of a carter carburetor?

a) Idle port

b) Metering rod

c) Float

d) Inlet valve

Answer: b

Explanation: The metering rod consists of several steps of diameter sizes at its bottom and is connected with the accelerator pedal through linkage. When the accelerator pedal is pressed, the throttle is held wide open and simultaneously the metering rod is lifted.

9. How many way valves are present in a damper plunger of an S U carburetor?

a) One

b) Two

c) Three

d) Four

Answer: a

Explanation: The damper plunger has a one-way valve in it. It regulates the rate of lift of piston but allows the same to fall freely when the throttle valve is closed. However the throttle valve is opened suddenly for acceleration, the lifting speed of the piston is retarded by the damper plunger.

10. To adjust which of the following a jet adjusting nut in provided in an S U carburetor?

a) Flow rate

b) Pressure

c) Mixture strength

d) Enthalpy

Answer: c

Explanation: The jet adjusting nut is meant to adjust mixture strength. Tightening the nut will raise the jet, thereby reducing the annular area for fuel flow. Similarly loosening the nut powers the jet and thus increases the fuel supply which is getting delivered to the engine.

11. Which of the following is the main advantage of drought type carburetor?

a) High volumetric efficiency

b) Leakage

c) Defective float

d) Jet overflowing

Answer: a

Explanation: The drought type is most widely used as it has high volumetric efficiency, gravity assist for the flow,etc. Whereas the leakage, defective float, and jet overflowing are the sign of a bad carburetor which is not desired.

12. Inside which of the following is the lower end of the needle placed in an S U carburetor?

a) Main

b) Pilot

c) Idling

d) Compensating

Answer: a

Explanation: The piston moves up and down, the needle also moves up and down .the lower end of the needle is inside the main jet. The up and down movement of the tapering needle causes the annular area for fuel flow to increase or decrease.

13. During which of the following the mixture tends to become richer in a single jet carburetor?

a) During winter

b) At low altitude

c) At high altitude

d) During idling

Answer: c

Explanation: At high altitudes, the mixture tends to become richer in a single jet carburetor as there is no supply of air at higher altitudes due to which the engine will have more fuel consumption when compared to an engine at sea level.

This set of Automotive Engine Auxiliary Systems Quiz focuses on “Petrol Engine Fuel Supply System – Carburettor Service and Adjustment”.

1. Using which among the following are the jets present in a carburetor should be cleaned?

a) Water and antifreeze

b) Diesel and petrol

c) Petrol and blast of air

d) Kerosene and wire

Answer: c

Explanation: The carburetor jets should first be cleaned with petrol and then with a blast of air and it should be never cleaned with wire because the screw adjustment helps in the smooth run of the engine at the required speed.

2. Concerning the idle port area which among the following decreases by screwing the idle screw?

a) Pressure

b) Clearance

c) Engine speed

d) Air – fuel

Answer: c

Explanation: Screwing the idle screw in the same direction decreases the idle port area and hence decreases the engine speed. Generally, this is done by screwing -in completely and then opening back by one or two turns.

3. What can we recognize if the color of the exhaust smoke is black?

a) Overheating of the engine

b) Loss of power

c) Unburnt carbon particle

d) Stalling of the engine

Answer: b

Explanation: The extra rich mixture when burnt has the colour of the exhaust in black which is caused due to unburnt carbon particles in the exhaust. Whereas the stalling of the engine, unburnt carbon particle and overheating of the engine happens for an extra weak mixture.

4. Which among the following is not an indication of the extra weak mixture?

a) Loss of power

b) Overheating of engine

c) Stalling of the engine

d) Surging while idling

Answer: d

Explanation: The extra weak mixture is recognized by flat spot while accelerating, stalling of the engine, loud popping in the carburetor, overheating of the engine and loss of the power. Whereas the surging while idling is due to extra rich mixture.

5. What is the main reason for throttle adjustment?

a) To know the play of the acceleration pedal

b) To decrease the engine speed

c) To check the float

d) Both decrease the engine speed andcheck the float

Answer: a

Explanation: The accelerator pedal throttle valve should be completely closed, while on pressing pedal fully, it should be in the full open position. This should be checked and in case of some action, the linkage must be adjusted, as provided for in the manufacturer’s manual.

6. What is the first step in removing the carburetor?

a) Remove the throttle and choke linkage

b) Adjustment of the carburetor screw

c) Wash with petrol

d) Clean with the blast of air

Answer: a

Explanation: To remove the carburetor, first of all, remove the air cleaner and disconnect the throttle and choke linkages. Next disconnect the vacuum advance unit and any other connection that many be there.

7. What is the number of rotation that has to be given to the idle screw to adjust the carburetor?

a) 2

b) 2.5

c) 1

d) 3

Answer: b

Explanation: The carburetor is screwed in completely and then opening back by two and a half turns. This screwing in the same decreases the idle port area and hence decreases the engine speed. The screw is adjusted until the engine runs smoothly at the required speed.

8. How many numbers of jets are present in a simple carburetor?

a) 1

b) 2

c) 3

d) 4

Answer: b

Explanation: There are 2 jets present in a simple carburetor they are the main jet and the pilot jet. These jets are very important and should never be cleaned with wire whereas they should be cleaned with petrol and then with a blast of air.

9. In which among the following does not depend on the carburetor to provide the correct mixture of air-fuel?

a) Idling

b) Crushing

c) Accelerating

d) Pressure relief

Answer: d

Explanation: The carburetor is a device that provides air-fuel mixture to the engine in all the working operation of an engine like the idling, crushing and accelerating period but whereas the pressure relief system has no connection to the carburetor.

10. Which among the following should never be used in the cleaning of jets present in a carburetor?

a) Petrol

b) Blast of air

c) Wire

d) Carb cleaner

Answer: c

Explanation: The jets present in a carburetor should never be cleaned with the wire as the wire damages the jets which may lead to an increase in the hole diameter. Whereas they can be cleaned with petrol followed by a blast of air and curb cleaner helps in cleaning any stubborn carbon particles present.

11. What can we say about the air-fuel mixture if the engine is stalling by itself?

a) The extra weak mixture is supplied

b) An extra rich mixture is supplied

c) Combustion in muffler

d) The color of the exhaust smoke is black

Answer: a

Explanation: When the engine is supplied with the extra weak mixture the stalling of the engine by itself is the indication when the extra weak mixture is supplied. Whereas combustion in the muffler and black exhaust smoke represents an extra rich mixture.

12. Which among the following is not an indication of a rich mixture?

a) Loud murder explosion

b) High fuel consumption

c) Surging while idling

d) Stalling of the engine

Answer: d

Explanation: The extra rich mixture can be recognized by Hugh fuel consumption, surging while idling, loud muffler explosion and black smoke from the exhaust. Whereas the stalling of the engine takes place only for an extra weak mixture.

13. Which among the following is not a secondary adjustment?

a) Accelerating pump

b) Metering rod

c) Floats

d) Idle adjuster

Answer: d

Explanation: Apart from the idle adjuster and throttle adjustment the other adjustments which are provided are accelerating pump, metering rod, floats,etc which must be performed as laid down in the user manual.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “ Petrol Injection”.

1. Which among the following tunes the fuel delivery to achieve the correct fuel ratio?

a) Float valve

b) Ecu

c) Oxygen sensor

d) Temperature sensor

Answer: b

Explanation: The ECU uses the information from the sensors to fine-tune the fuel delivery to achieve the just correct fuel ratio. The sensors monitor the mass of air entering the engine and also the amount of oxygen in the exhaust.

2. Which among the following is defined as the amount of time the injector stays open and also determines the amount of fuel supplied to the engine?

a) Flat spot

b) Pulse radiation

c) Pulse width

d) Dark pulse

Answer: c

Explanation: The amount of time the injector stays open determines the amount of fuel supplied to the engine it is called the pulse width. This time duration and the amount of fuel flowing into the combustion chamber is controlled by the ECU.

3. Which among the following is not a factor affecting the pulse width?

a) Coolant temperature

b) Oxygen level in the exhaust

c) Base pulse width

d) Muffler explosion

Answer: d

Explanation: The factors affecting the pulse width are the base pulse width, the coolant temperature and the factors for oxygen level in the exhaust.Whereas the muffler explosion takes place due to the unburnt fuel In the engine, which completes its combustion in the muffler.

4. Which type of control valve is used in the operation of the injector?

a) Mechanical

b) Electrical

c) Pneumatic

d) Hydraulic

Answer: b

Explanation: The Petrol is injected by an electronically controlled valve, called an injector. The injector has nozzles on its circumference through which the petrol or gasoline is sprayed into the combustion chamber which is controlled by the ECU.

5. Which among the following is not an advantage of petrol injection?

a) Fuel consumption is less

b) Rapid response to throttle

c) High-quality fuel distribution

d) Low efficiency

Answer: d

Explanation: The advantages of petrol injection are high-quality fuel distribution, fuel consumption is less, the engine to throttle control is very rapid, etc. Whereas the petrol injection system provides more efficiency.

6. Which of the following is not a component of a petrol injection system?

a) Injection pump

b) Injection nozzle

c) Pipelines

d) Compression ring

Answer: d

Explanation: The injector is made up of a precise fuel injection pump, injection nozzle through the fuel enters the combustion chamber and pipelines are provided for each cylinder. Whereas the compression ring has no part in the petrol injection system.

7. How is the air-fuel mixture for full power mode?

a) Rich

b) Lean

c) Stoichiometric

d) Very lean

Answer: a

Explanation: Fuel – air mixture is made richer in the full power mode and the fuel is sprayed in during the intake stroke which is controlled by the ECU. The ECU controls the amount of fuel injected based upon the airflow into the engine.

8. Where is the injector placed in the direct injection system?

a) Intake manifold

b) Next to the inlet valve

c) Inside the cylinder

d) Near the throttle body

Answer: c

Explanation: The fuel injector is placed directly into the cylinder and sprayed as per the ECU signal. The intake valve allows only the air into the combustion chamber and the fuel is sprayed – indirectly through an injector.

9. In which of the following stroke concerning ultra-lean mode the fuel is injected?

a) Intake

b) Compression

c) Expansion

d) Exhaust

Answer: b

Explanation: In the ultra-lean mode the fuel is injected later on as the piston is moving up on its compression stroke. This forces the fuel-air charge right up to the spark plug points for the best burning condition. The combustion takes place partly in the cylinder and party in the shaped piston crown.

10. How is the time given for the mixing of air and petrol concerning the port injection system?

a) More

b) Less

c) No time

d) Has no effect

Answer: a

Explanation: In the port injection the injection is made in such a way that it gives more time for the mixing of air and petrol moreover the system is more precise than throttle body type since the fuel delivery does not depend upon air to carry the fuel through the intake manifold.

11. Without any fear of which of the following higher compression ratios can be adopted in the petrol injection system?

a) Ignition lag

b) After burning

c) Detonation

d) Flame propagation

Answer: c

Explanation: In a fuel injector a very high-quality fuel distribution is obtained due to which higher compression ratios can be adopted without and danger of detonation occurring. Whereas the ignition lag, after burning and flame propagation are the process of combustion.

12. How many numbers of a circuit are required in the computer to control injection in a Throttle body injection?

a) 5

b) 1

c) 2

d) 3

Answer: b

Explanation: The computer requires just one circuit to control the process of injection in a vehicle. Thus this is a less costly but less precise system. Never the less the throttle body injection controls the fuel better than the carburetor.

13. How is the piston crown created in a direct injection to help a minimum of air and fuel before combustion?

a) Scavenged

b) Swirling vortex

c) Plain

d) Circle

Answer: b

Explanation: In a direct injection the piston crown is designed in such a way that it creates a swirling vortex to help mix the fuel and air before combustion. The piston crown also has a cavity on it for ultra-lean-burn conditions.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Fuel Injection System”.

1. How are the unit injectors operated in a Common rail fuel injection system?

a) Crankshaft

b) Rocker arms

c) Belt

d) Motor

Answer: b

Explanation: The common rail fuel injection system the unit injectors are operated by rocker arms and springs similar to the engine valves. A linkage connects the control racks of all the unit injectors, so that fuel injection in all the cylinders may be equal and simultaneously controlled.

2. Which of the following is used to return the excess fuel in the rail to the fuel tank?

a) Float valve

b) Relief valve

c) Hand pump

d) Governor

Answer: b

Explanation: The excess fuel in the rail is returned to the tank by the means of a relief valve present in the circuit. Then again the fuel is taken from fuel tank by the feed pump and is supplied at low pressure through a filter, to the low-pressure common rail and therefore, to all the unit injectors.

3. Which of the following can be removed by using a hand priming lever without turning the engine on in an Individual pump fuel injection system?

a) Air bled out

b) Temperature

c) Oil

d) Coolant

Answer: a

Explanation: The pump is provided with a hand priming lever so that the diesel oil can be forced into the system and the air bled out without turning the engine. The fuel is passed through a filter and hence to the fuel injection pump.

4. Which among the following is provided in an injection pump to provide automatic speed control?

a) Filter

b) Feed pump

c) Governor

d) Injector

Answer: c

Explanation: The injection pump contains a governor which provides automatic speed control, relative to any set position of the accelerator pedal. Any excess fuel after the lubrication of the injector nozzle is returned to the fuel tank. This system can be seen in the Swaraj Mazda SL engine.

5. Which of the following types of injection is used in the Common rail fuel injection system?

a) Solid injection

b) Air injection

c) Both solid and air injection

d) Oil injection

Answer: a

Explanation: A solid injection system, only the liquid fuel is injected due to which the common rail fuel injection system and individual pump fuel injection system are an example of solid injection.

6. Along with compressed air which of the following is injected inside the cylinder?

a) Antifreeze

b) Coolant

c) Liquid fuel

d) both coolant and liquid fuel

Answer: c

Explanation: In an air injection system liquid fuel is injected along with compressed air. The air injection is less reliable and less efficient. Whereas the coolant is added inside the radiator tank to cool the engine during a long run.

7. What is the pressure range in MPa of the compressed air that has been injected in an air injection?

a) 5

b) 7

c) 6

d) 8

Answer: b

Explanation: The air injection system has a liquid fuel injected with compressed air at 7MPa due to this reason it has been obsolete. This makes the air injection system less reliable, less efficient and requires a compressor all the time.

8. How much percentage of the power output of the engine is used during the injection process in an air injection system?

a) 5

b) 10

c) 15

d) 20

Answer: b

Explanation: The air injection system is less reliable, less efficient and requires an air compressor for supplying 7MPa of compressed air with the fuel which consumes up to 10% of the power output of the engine.

9. Which of the following is the correct flow of fuel in an individual pump fuel injection system?

a) Fuel tank – filter – feed pump – injector

b) Fuel tank – filter – injector- feed pump

c) Fuel tank – feed pump – filter – injector

d) Filter- feed pump – fuel tank – injector

Answer: c

Explanation: The fuel flows from the fuel tank to the feed pump where the pressure is increased and then the fuel is filtered by the filter and then it is sent to the injector. Therefore the correct sequence of the fuel flow is fuel tank – feed pump – filer – injector.

10. What is the main function of a good fuel filter concerning the injector?

a) Faulty spraying

b) Leakage

c) Increased fuel consumption

d) Filter moisture present

Answer: d

Explanation: The abrasive matter would also cause faulty spraying and leakage in the injector thus resulting in increased fuel consumption whereas a good fuel filter should absorb any moisture and dirt present in the fuel.

11. Which of the following is used from the engine to drive a gear-driven injection pump?

a) Crankshaft

b) Camshaft

c) Motor

d) Alternator

Answer: b

Explanation: The injection pump is gear driven from the engine camshaft so that it is driven at half the engine speed. The injection pump consists of a governor which provides automatic speed control, relative to any set position of the accelerator pedal.

12. What is the range of the cranking compression pressure in the range of KP in a diesel engine?

a) 1000

b) 2000

c) 3000

d) 10000

Answer: c

Explanation: The cranking compression pressure on a diesel engine is about 3000KPa. Compression pressure is the pressure that is used to compress the charge inside the cylinder and rise it to the ignition temperature.

13. What is the range in MPa of pressure injection in diesel engines?

a) 100

b) 200

c) 300

d) 400

Answer: b

Explanation: In diesel engines, the injection pressure can reach as High as 200MPa. This high pressure is required to atomize the fuel properly for complete combustion so that the emissions can be controlled to a greater extent.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Fuel Injection Pump”.

1. Which of the following helps in the fuel distribution in a distributor type fuel injection pump?

a) Crankshaft

b) Rocker arms

c) Rotor

d) Motor

Answer: c

Explanation: In a distributor type of fuel injection pump the fuel is distributed to each cylinder using a rotor. The rotor has a central longitudinal passage and set of radial holes which depends on the engine configuration.

2. To which of the following the number of radial holes equal in a distributor type fuel injection pump?

a) To the float valve

b) To the number of the engine cylinder

c) To the number of gears

d) To the number of governors

Answer: b

Explanation: In a distributor type fuel injection pump there is a set of radial holes  equal to the number of the engine cylinder. Similarly, the outer sleeve also has a set of an equal number of holes  which are offset from the suction ports.

3. How is the fuel injection time controlled in a distributor type fuel injection pump?

a) Internal-cam ring

b) Crankshaft

c) Motor

d) Rotor

Answer: a

Explanation: The fuel injection timing in a distributor type of fuel injection pump is controlled by rotating the internal-cam ring. As the engine speed increases, the fuel feed pump delivery pressure increases.

4. Which of the following is moved to a position so that the excess fuel can be supplied during cold start conditions?

a) Filter

b) Spark plug

c) Control rack

d) Injector

Answer: c

Explanation: For starting the engine from cold, more fuel is required to be injected which is done by moving the control rack to a position where the excess fuel is delivered by the pump. The rack has to be brought to a normal position immediately after the engine starts.

5. Which of the following type part is not used in jerk type fuel injection pump?

a) Plunger

b) Delivery valve

c) Control sleeve

d) Rotor

Answer: d

Explanation: The main parts of a jerk type fuel injection pump are the delivery valve, the plunger, the control sleeve, and the control rack. Where the delivery valve is spring-loaded. Whereas the rotor is absent in this type of injection pump.

6. Which of the decreases when the plunger is given an anticlockwise rotation?

a) Compressed air

b) Fuel-injected

c) Coolant supply

d) Lubricating oil

Answer: b

Explanation: When the plunger rotates in the anticlockwise direction the fuel injection per stroke decreases whereas when a clockwise rotation will delay the end of delivery, increasing the effective plunger stroke and consequently the fuel supply injected.

7. Which of the following material is used in the fabrication of pump housing?

a) Aluminum alloy

b) Cast iron

c) Copper

d) Brass

Answer: a

Explanation: The material used in the fabrication of pump housing is either a single aluminum alloy casting or aluminum alloy cam box is bolted on to a pumping head of steel and the governor housing is an extension of the cam box.

8. How many degrees of advancement is provided by injection timer?

a) 5

b) 8

c) 9

d) 6

Answer: b

Explanation: The timing of injection will be required to be advanced with an increase in engine speed. This advancement is done by injection timer which provides a maximum of 8 degrees of Advance. The timer is mounted on the front end of the injection pump and works on the principle of centrifugal force.

9. Which type of shape is provided on the plunger so that the quantity of fuel injected can be controlled?

a) Helix

b) Circle

c) Elliptical

d) Rectangular

Answer: a

Explanation: The plunged contains a helix at its upper end which serves to control the quantity of fuel to be injected. As the helix uncovers the spill port, the fuel escapes through the vertical slot in the plunger and spill port and pressure are released, shutting the valve down on its seat.

10. Which among the following is not a part of the pump housing?

a) Cambox

b) Pumping head

c) Governor

d) Alternator

Answer: d

Explanation: The pump housing is the main housing that contains cambox  and the pumping head which is made of single aluminum alloy whereas the alternator has no role in the pump housing.

11. Which of the following increases concerning the metering valve when the accelerator pedal is pressed?

a) Temperature

b) Pressure

c) Area

d) Enthalpy

Answer: c

Explanation: A metering valve controlled by the governor regulates the amount of fuel entering the rotor. Pressing the accelerator pedal increases the area of the metering port allowing more fuel to enter the rotor, thereby increasing the engine speed.

12. How many weights are connected between the input and the output sides of the timer?

a) 1

b) 2

c) 3

d) 4

Answer: b

Explanation: Two centrifugal weights connect the input and output sides of the timer. When the speed increases, the weights fly apart causing the output segment plates and thereby the camshaft of the fuel injection pump to turn in the direction of rotation.

13. Which of the following is not a function of the fuel injection pump?

a) Deliver accurately

b) High pressure

c) Correct sequence

d) Dribbling

Answer: d

Explanation: The function of a fuel injection pump is to deliver accurately, the metered quantity of fuel under high pressure, at the correct instant and in the correct sequence, to the injector fitted on each engine cylinder.

This set of Automotive Engine Design Assessment Questions and Answers focuses on “Diesel Engine Fuel Supply System – Fuel Injector”.

1. By adjusting which of the following we can vary the opening fuel line pressure?

a) Spring

b) Rocker arms

c) Rotor

d) Motor

Answer: a

Explanation: The actual opening fuel- line pressure can be varied by adjusting the initial degree of spring compression. The fuel spray continues till the delivery from the injection pump is exhausted when the spring pressure again suddenly closes the nozzle valve back on its own.

2. For what purpose a small quantity of fuel is purposely allowed to mean between the nozzle valve and its guide?

a) To control the temperature

b) To control the pressure

c) To lubricate

d) To keep a check-in entropy

Answer: c

Explanation: A small quantity of fuel is purposely allowed to leak between the nozzle valve and its guide for lubrication purposes. The fuel accumulated around the spindle In this way is drained back to the fuel tank through the leak-off connection.

3. In which type of combustion chamber hole-type nozzle are preferred?

a) Pre-combustion

b) Open type

c) Both pre-combustion and self-cleaning

d) Self-cleaning

Answer: b

Explanation: The nozzle used may be classified broadly into the hole type and the pintle type wherein the hole type nozzles are generally used in engines with the open type combustion chamber and the pintle type nozzle has an extension.

4. What is the opening pressure range in MPa of a hole-type nozzle?

a) 5-7

b) 10-17

c) 17-34

d) 37-54

Answer: c

Explanation: The opening pressure of the hole-type nozzle varies from 17 to 34MPa. Due to which the hole type fuel injector has good fuel atomization and this happens in a proper quantity. And the fuel is injected in the cylinder properly.

5. Which of the following is not a property of a good fuel injector?

a) Good atomization

b) Fuel uniformity

c) Faulty spraying

d) Proper injection angle

Answer: d

Explanation: A good nozzle should atomize the fuel properly which is being supplied and it should also maintain the fuel uniformly and it also needs to maintain proper injection angle and proper direction of the fuel spray.

6. What is the shape of the lower pintle end in a throttling pintle type?

a) Rectangle

b) Truncated cone

c) Sphere

d) Circle

Answer: b

Explanation: The pintle type nozzle carries an extension, which produces a hollow cone-type spray. The pintle is much longer and is also shaped like a truncated cone at its lower end. Such shape causes only a small amount of the fuel to be injected at the ignition start.

7. What is the operating pressure in MPa of a pintle type nozzle?

a) 3-5

b) 5-7

c) 7-15

d) 17-25

Answer: c

Explanation: In pintle type nozzle the rate of injection increasing gradually as the pintle: protrudes further from the nozzle end. The opening pressure of the pintle type nozzle varies from 7 to 15MPa which gives more fuel uniformity.

8. In which type of combustion chamber pintle type nozzle injectors are preferred?

a) Pre – combustion

b) Open type

c) Self-cleaning

d) Both open type and self-cleaning

Answer: a

Explanation: There are two types of nozzle mainly the hole type and the pintle type nozzle whereas the pintle type nozzle is preferred in common engines with pre-combustion chambers and some special swirl chambers.

9. What is the hole angle degree in an upward direction in a multi-hole nozzle?

a) 10

b) 15

c) 17

d) 20

Answer: d

Explanation: In a multi-nozzle injector the nozzle consist of several holes bored in these tip of the nozzle. The number of while varies from 4 to 18 and the whole angle is about 20 degrees upwards.

10. Which among the following is not a part of the injector?

a) Nozzle

b) Nozzle holder

c) Spark plug

d) Adjusting screw

Answer: c

Explanation: The injector mainly consists of the nozzle, the.nozzle holder, the adjusting screw which is connected to the locking nut, spindle, valve, leak-off port, etc whereas there is no spark plug component in a fuel injector.

11. Which among the following is an advantage of the pintle type nozzle?

a) Self-cleaning

b) Uneven atomization

c) Different injection angle

d) Fault spraying

Answer: a

Explanation: The pintle type of nozzle carries an extension, which produces a hollow cone-type spray. Such nozzle has the advantage of being self-cleaning and the advantage of a good nozzle is to atomize the fuel uniformly and to maintain proper injection angle and direction.

12. How much is the angle of spray cone in a single hole nozzle?

a) 10

b) 20

c) 15

d) 17

Answer: c

Explanation: The single hole nozzle has a spray cone angle about 15 degrees and one of the major disadvantages of this nozzle is that they tend to dribble. Besides, their spray angle is too narrow to facilitate good mixing unless higher velocities are used.

13. What is the use of the additional hole present in a pintaux nozzle?

a) For self-cleaning

b) High-pressure relief

c) It injects a small amount of fuel

d) For temperature control

Answer: c

Explanation: The function of the auxiliary hole drilled in the nozzle body is to inject a small amount of fuel through its addition hole which is called a pilot injection in an upstream direction slightly before the main injection.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Diesel Engine Fuel Supply System – Governor”

1. Based on which principle does the hydraulic governor works?

a) No inverting amplifier

b) Inverted hydraulic amplifier

c) Low pass filter

d) High pass filter

Answer: b

Explanation: A hydraulic governor for example the CAV works on the principle of an inverted hydraulic amplifier wherein a small pressure changes in some part of the system producing in some other part, an opposite change of much greater amplitude.

2. Which of the following is an example of a maximum speed governor?

a) Pneumatic governor

b) Mechanical governor

c) Hydraulic governor

d) Both hydraulic and pneumatic

Answer: b

Explanation: In a mechanical governor below this maximum speed, the control rack on the fuel injection pump may be directly operated by the driver through accelerator pedal and linkage, with a provision to override the driver control at maximum speed which is limited by the amount of spring tension. Such a governor is called the maximum speed governor.

3. Which of the following is not a part of a pneumatic governor?

a) Vacuum pipe

b) Venturi unit

c) Diaphragm

d) Glow plug

Answer: d

Explanation: The pneumatic governor consists of two main parts, the venturi unit, and the diaphragm unit. The venturi unit is connected to the engine inlet manifold and the diaphragm unit is fitted on the fuel injection pump. The two units are connected by a vacuum pipe.

4. The difference between which of the following is termed as governor overrun?

a) Between governor hysteresis and governor runoff

b) Between governor runoff and governor cut-in speed

c) Between governor cut-in speed and governor hysteresis

d) Between governor cut-off speed and governor cut-in speed

Answer: d

Explanation: Governor overrun is defined as the difference between the governor cut-off speed and the governor cut-in speed. Governor overrun is an important terminology in a governor along with governor hysteresis etc.

5. Which of the following links the accelerator pedal and pump control rack in a speed governor?

a) Governor

b) Venturi control unit

c) Fuel injector

d) Plunger

Answer: a

Explanation: The accelerator pedal and the pump control rack are linked only through the governor. The driver,then, changes spring tension with the help of the accelerator pedal and hence fix the speed of the engine in a vehicle.

6. What of the following gets actuated when the spring tension is adjusted and the fuel delivery decreases?

a) Control rack

b) Accelerator pedal

c) Cam

d) Sleeve

Answer: a

Explanation: The spring tension can be so adjusted as to actuate the control rack for a decrease in fuel delivery at some maximum speed. Below this maximum speed, the control rack on the fuel injection pump may be directly operated by the driver through accelerator pedal and linkage, with a provision to override the driver control at maximum speed which is limited by the spring tension.

7. Which of the following is defined as the speed of the fuel injection pump at which the control rod moves away from the maximum fuel to stop with the accelerator lever set for maximum speed?

a) Governor cut-off speed

b) Governor hysteresis

c) Governor run-off

d) Governor cut-in speed

Answer: d

Explanation: The terminology governor cut-in speed is the speed of the fuel injection pump at which the control rod just starts to move away from the maximum fuel stop with the accelerator lever set for maximum output.

8. Which of the following gives the drive to the governor shaft?

a) Motor

b) Engine

c) Alternator

d) Ignition coil

Answer: b

Explanation: The two spring-loaded weights are mounted on the governor shaft which gets its drive from the engine. At one end, the bell crank lever carries balls whereas their other ends touch the lower surface of the flange of a sleeve on the governor shaft.

9. Which of the following is defined as the percentage speed change when the control rod is moved by the governor from the maximum fuel delivery position to the no-fuel delivery position?

a) Governor hysteresis

b) Governor run-off

c) Governor cut-in speed

d) Governor cut-off speed

Answer: b

Explanation: The terminology governor run-off is defined as the percentage speed change when the control rod is moved by the governor from the maximum fuel delivery position to the no- fuel delivery position.

10. Which of the following controls the position of the butterfly valve in the venturi unit?

a) Motor

b) Spring

c) Accelerator pedal

d) Adjusting screw

Answer: c

Explanation: Accelerator pedal controls the position of the butterfly valve in the venturi unit and hence the amount of vacuum from the inlet manifold,which is applied to the diaphragm via the vacuum pipe. As the diaphragm is connected to the fuel pump control rack.

11. Which of the following is defined as the difference between the governor cutoff speed at which the fuel delivery stops with the increasing injection pump speed and the cut-off speed at which point fuel delivery just restarts with the decreasing injection pump speed?

a) Governor hysteresis

b) Governor run-off

c) Governor cut-in speed

d) Governor cut-off speed

Answer: a

Explanation: The terminology governor hysterisis defined as the difference between the governor cutoff speed at which the fuel delivery stops with the increasing injection pump speed and the cut-off speed at which point fuel delivery just restarts with the decreasing injection pump speed.

12. Which of the following helps in the idling spring adjustment?

a) Spring and lever

b) Camshaft

c) Rack and pinion

d) Gears meshed

Answer: a

Explanation: The idling spring adjustment is provided utilizing a separate spring and lever, the spring tension can be adjusted with an adjusting nut provided. Whereas the camshaft, rack, and pinion and gears have no operation in the idling spring.

13. As the engine speed increases, which force acts against the spring tension?

a) Rolling force

b) Friction force

c) Centrifugal force

d) Both rolling and friction force

Answer: c

Explanation: As the engine speed increases, the centrifugal force due to weights acts against the spring tension. Once the former exceeds the latter, the weights fly apart, causing the other ends of the bell crank levers to raise the sleeve.

This set of Automotive Engine Auxiliary Systems MCQs focuses on “Modern Common Rail Fuel Injection System”.

1. How are the injectors activated in a modern common rail fuel injection system?

a) Spring

b) Solenoid valve

c) Rotor

d) Motor

Answer: b

Explanation: The fuel injectors present in the modern common rail fuel system are activated by the solenoid valve. Solenoid valves and the fuel pump are electronically controlled. Thus, the common rail serves as the high-pressure reservoir independent of the engine speed.

2. Which of the following helps in the increase of the engine torque at lower engine speeds?

a) Throttle body injection

b) The common rail injection system

c) Port injection

d) Retarded post-injection

Answer: b

Explanation: The common rail injection system, the injection pressure is possible even at low engine speeds which leads to more complete combustion of the fuel. It also increases the engine torque in the lower engine speed ranges.

3. In which type of injection mode the exhaust gas temperature for the regeneration of the particulate filter is increased?

a) Pilot injection mode

b) Retarded post ignition mode

c) Main injection

d) Double pre injection

Answer: b

Explanation: After the main injection phase, after which post-injection spurt of fuel is added, which reduces soot emissions. Finally, after upto 180 degrees of the crankshaft, a retarded post ignition occurs, which acts as a reducing agent for NOx and increases the exhaust gas temperature for the regeneration of the particulate filter.

4. How many times is the fuel being injected in one cycle of a modern automotive diesel engine?

a) 5-7

b) 7-10

c) 4-5

d) 10-12

Answer: c

Explanation: In modern automotive diesel engines, the fuel is not injected once in a cycle. Instead, the fuel injection is done upto 4-5 times in one cycle. There are different modes of injection depending on the time they have been injected.

5. Which of the following is not a property for injector open time duration?

a) Density of fuel

b) Dynamic compressibility

c) Injection pressure

d) Engine temperature

Answer: d

Explanation: The fuel is directly injected into the combustion chamber, the fuel mass flow would depend upon the difference between the injection and combustion chamber pressure,the density of fuel and dynamic compressibility of the fuel.

6. Which of the following is an example of a radial piston pump?

a) Low-pressure pump

b) High-pressure pump

c) Common rail

d) ECU

Answer: b

Explanation: Radial piston pump is an example of a high-pressure pump that generates high pressure in the accumulator, the rail independent of engine speed, and injected fuel quantity. The engine drives the pump through the coupling, gear wheel, chain, or toothed belt.

7. Which of the following does not depend on the fuel quantity injected?

a) System pressure

b) Duration of injection

c) Size and shape of the nozzle

d) Alternator speed

Answer: d

Explanation: The fuel is injected in the engine combustion chamber by the injection nozzle of an injector controlled by a solenoid-operated valve. The injector receives its operation signal from ECU. The system pressure, the duration of injection, and the size of the nozzle determine the fuel quantity injected.

8. Which of the following valve guards the system against excess pressure?

a) Pressure limiter

b) Inlet

c) Outlet

d) Both inlet and Outlet

Answer: a

Explanation: The fuel pressure in the rail is independent of engine speed and the injected fuel quantity. Flow limiters protect the system against the consequences of a potential leak of the injector. A pressure limiter valve guards the system against excess pressure.

9. How many numbers of engine variables are individually controlled in a common rail fuel injection system?

a) 1

b) 5

c) 7

d) 3

Answer: d

Explanation: The combustion behavior in diesel engines is affected by three variables,which are the timing of injection start, duration of injection, and discharge curve which all are individually controlled in a common rain fuel injection system.

10. Which among the following is not a component of the common rail fuel injection system?

a) ECU

b) Injector

c) Spark plug

d) Electric fuel pump

Answer: c

Explanation: The ECU takes the reading from the sensor based on the reading the ECU controls the fuel delivery from the electric fuel pump with prefilter and send the fuel to the high-pressure pump with a pressure regulator valve and then fuel is sent to the common rail than with the injector the fuel is injected.

11. Which among the following is the correct full form of ECU?

a) Electrical control unity

b) Electrical control unit

c) Electronic control unity

d) Electronic control unit

Answer: d

Explanation: The ECU is an electronic control unit. The ECU has various program maps stored in it. The ECU controls the fuel pressure in the common rail, integrated diagnosis-sensor monitoring and malfunction recognition, and other supplementary functions.

12. How much amount in millimeter cube of fuel is injected in a pilot injection phase?

a) 1

b) 2

c) 5

d) 7

Answer: a

Explanation: The pilot injection also called a pure injection which is a short bust of fuel before the main injection during each combustion cycle is in the range of 1millimeter and 50-millimetercube for full load main injection. The injection duration is about 1 to 2milliseconds.

13. Which is the sensor used to sense the pressure of the common rail?

a) Rail pressure sensor

b) Mass airflow sensor

c) Oxygen sensor

d) Thermostat

Answer: a

Explanation: The fuel from the fuel tank is pumped by a low-pressure electric fuel pump through a filter, to the high-pressure pump, which builds up the high pressure in the common rail with the help of a pressure regulator valve controlled by ECU through a rail pressure sensor.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Types of Ignition System”.

1. Which of the following is defined as the actual high voltage at which the spark occurs?

a) Cut-in voltage

b) Saturated voltage

c) Breakdown voltage

d) Cut-off voltage

Answer: c

Explanation: A battery of 12 volts is generally preferred. However, a very high voltage surge of about 25,000 volts in modern engines for ignition purposes. The actual high voltage at which the spark occurs is called the breakdown voltage.

2. Which of the following factors spark creating voltage does not depend on?

a) The gap and polarity

b) Moisture

c) Plug insulation

d) Engine speed

Answer: d

Explanation: The voltage at which spark occurs is called breakdown voltage and it depends upon so many factors like the gap, polarity and condition of plug electrodes, condition of plug insulation, moisture on the distributor cap, and spark plugs.

3. What is the function of the ignition coil which is simply a transformer?

a) Step up the current

b) Step down the current

c) Step down the voltage

d) Step up the voltage

Answer: d

Explanation: The ignition coil is simply a transformer with certain characteristics making it suitable for its special use but impairing to some extent its efficiency as a transformer. It serves to set up the low battery voltage to high voltage.

4. What is the total resistance in ohms offered by primary winding in the ignition coil?

a) 5

b) 7

c) 3

d) 4

Answer: c

Explanation: The battery winding consists of 200-300 turns of thick wire of total resistance about 3 ohms while the secondary is made up of a large number of turns about 15,000-20,000 of fine wire.

5. Which of the following is used as a material for insulation in the ignition coil?

a) Metal

b) Ceramic

c) Paper

d) Wood

Answer: c

Explanation: The voltage difference between the adjacent turns is small, only think insulation is required and enameled wire is used. However, there is sufficient voltage drop between the layers and for this purpose, the paper is used for insulation.

6. What is the type of resistor that is used to avoid overheating and to decrease the amount of current in the primary circuit?

a) Ballast resistor

b) Thermistor

c) Photoresistor

d) Rheostats

Answer: a

Explanation: When the engine is running at a slow speed, the contact breaker point is closed for a comparatively longer period. This causes overheating of the induction coil. To avoid this a ballast resistance is inserted in the primary circuit of the coil.

7. What is the gap in millimeters in the contact breaker?

a) 0.35-0.45

b) 0.5-0.7

c) 0.7-0.9

d) 1-1.5

Answer: a

Explanation: The contact breaker gap is between 0.35 to 0.45 millimeters. In case the gap is too small the points will not open for the period which is sufficient for the coil to function. This will cause the points to burn rapidly and the engine to misfire at all the speeds.

8. How can the center electrode make concerning earth to increase the plug life?

a) Positive

b) Negative

c) Short circuit

d) Ground

Answer: b

Explanation: The advantage of negative earth type is that comparatively less voltage is required for the electrons to jump from the central electrode which is hotter than the outer electrode. Further, the center electrode is made negative concerning the earth, thus the plug life is increased.

9. Which of the following is used to store the inertia of the current flowing during the contact period?

a) Contact breaker

b) Condenser

c) Distributor

d) Ballast resistor

Answer: b

Explanation: Condenser is a kind of plastic container in which the energy due to the inertia of the current flowing during the contact period is stored. The condenser absorbs excess energy during the break period.

10. Where is the condenser placed in the ignition circuit?

a) Contact breaker

b) Distributor housing

c) Ballast resistor

d) Spark plug

Answer: b

Explanation: The condenser is always mounted in the distributor housing. The condenser consists of metallic plates usually of tin foil or aluminum foil separated by thin sheets of insulating paper or mica.

11. Which among the following is not a requirement of a good contact breaker?

a) Must open and close at the correct time

b) Contacts must close without bounce

c) Minimum corrosion

d) Contacts should open with fling

Answer: d

Explanation: The essential requirements of a good contact breaker are the contact must open and close at the correct time, the contacts must close without bounce, the corrosion of the points should be minimum. Whereas the contacts must open without fling.

12. Which is the material used to make the rotor and a cap of the distributor?

a) Bakelite

b) Ceramic

c) Paper

d) Wood

Answer: c

Explanation: The distributor proper consist of a rotor and a cap, both of these are made of bakelite. Apart from the bakelite, the other material used is alkyl plastic phenol resin, fiberglass-reinforced polyester resin plastic.

13. How is the voltage of the used spark plug to fire when compared to a new spark plug?

a) High voltage

b) Less voltage

c) Has no effect

d) Depends on the current value

Answer: a

Explanation: Used spark plugs may require a fairly higher voltage to fire than the new plugs because of the increase in the gap and rounding off of the center electrode. In a given engine the highest ignition voltage is required during part throttle acceleration.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Ignition Advance”

1. Which of the following is not a factor affecting the ignition advancement?

a) Nature of fuel

b) Engine speed

c) Entropy

d) Load

Answer: c

Explanation: The various factors affecting the ignition advance are the nature of fuel, engine speed, load, engine temperature, compression ratio, engine coolant and intake air temperature, turbo boost pressure. Whereas entropy has no role in the ignition advance.

2. Which among the following increases with speed which in turn improves the rate of combustion?

a) Enthalpy

b) Turbulence

c) Vaccum

d) Entropy

Answer: b

Explanation: For engines with higher speed requires more ignition advancement but the turbulence increases with speed, which improves the rate of combustion, requiring lesser advance. The net requirement, however, remains the increased advance at higher speed.

3. Which among the following emission increases with ignition advancement?

a) Carbon monoxide 

b) Sulfur

c) Nitrogen oxides 

d) Particulate matter

Answer: c

Explanation: Nitrogen oxides  emission increases with an increase in ignition advance. However, emission of CO is not much affected by ignition timing, rather the same is influenced by air/fuel ratio. And there is very little effect of ignition advance on hydrocarbon.

4. How many numbersof weights are present in a centrifugal advancement method?

a) 2

b) 3

c) 4

d) 1

Answer: a

Explanation: The distributor shaft is actually in two pieces connected through centrifugal advance arrangement, which consist of two centrifugal weights. These weights are pinned and connected with the breaker plate using spring.

5. What is the general crankshaft degree range of advancement in a centrifugal advance system?

a) 10-15

b) 20-25

c) 26-32

d) 34-38

Answer: d

Explanation: In general the crankshaft degree of advancement in a centrifugal advance type varies between 34 and 38 crankshaft degrees, including the initial timing,which is usually about 8-degree bottom dead center.

6. Which of the following part vacuum is referred to as a ported vacuum in a vacuum advance type?

a) Crankcase

b) Engine deck

c) Radiator

d) Carburetor

Answer: d

Explanation: In a vacuum advance type one side of the diaphragm is open to the atmosphere while the other side is subjected to the vacuum from the carburetor. A return spring on the vacuum side of the diaphragm keeps the advance unit at zero advance if no vacuum is applied as during idling.

7. In the below-shown diagram of a vacuum advance type carburetor, what is the name of the part?

a) Fuel feed

b) Diaphragm

c) Cooler

d) ECU

Answer: b

Explanation: The part in between the engine side and distributor is known as diaphragm. The vacuum advance type consists of a carburetor, diaphragm, and distributor. Vacuum advance unit senses any variation of ported or manifold vacuum, which are a direct measure of engine load.

8. Which among the following is provided in a vacuum advance type to keep the advance unit at zero if no vacuum is applied as during idling?

a) Carburetor

b) Diaphragm

c) Centrifugal weights

d) Return spring

Answer: d

Explanation: A return spring on the vacuum side of the diaphragm keeps the advance unit at zero advance if no vacuum is applied as during idling. However, when the throttle is opened the vacuum is applied which moves the diaphragm against the return spring.

9. Which of the following condition is taken care of by the centrifugal advance mechanism?

a) Speed

b) Load

c) Temperature

d) Detonation

Answer: a

Explanation: The centrifugal advance mechanism takes care of speed only and not the load conditions, which are looked after by the vacuum advance mechanism. Further, the vacuum advance is independent of centrifugal advance and this mechanism is when the engine is running under light load and moderate-high speed.

10. Which of the following type of advancement uses the ECU?

a) Vacuum advance

b) Centrifugal advance

c) Complete vacuum control

d) Computerized advance control

Answer: d

Explanation: The computerized advance control uses a computer with memory, a timing map, which contains spark advance values for all combustion of speed, load, and other conditions. Based upon the signals received from various sensors, the ECU sends the signal to the ignition coil at the precise moment indicated in the timing map.

11. How many numbers of vacuum openings are provided in the carburetor in a complete vacuum control type?

a) 4

b) 2

c) 16

d) 8

Answer: b

Explanation: In a complete vacuum control type there are two vacuum openings in the carburetor. One is at the venturi and the other one is just on the atmospheric side of the throttle when the same is closed.

12. Which of the following is used to define ignition advance?

a) Clearance volume

b) Cylinder top dead center

c) Compression height

d) Detonation length

Answer: b

Explanation: The difference between ignition delay and the occurrence of spark in terms of degree of crankshaft rotation, is termed as ignition advance. It is defined concerning the cylinder top dead position.

13. Which of the following is termed as the maximum permissible number of degrees per second, change during acceleration to keep up with the timing requirement?

a) Attack rate

b) After burning

c) Detonation

d) Dribbling

Answer: a

Explanation: The ignition timing during acceleration should have a sufficient attack rate to keep up with the timing requirement. Attack rate is the maximum permissible number if degree per second, change which may be as high as possible in some high-performance engines.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Conventional Ignition System – Spark Plug”.

1. Which of the following is the hottest part of the spark plug?

a) Terminal

b) Insulator tip

c) Shell

d) Gasket

Answer: b

Explanation: The insulator nose length is the distance from the firing end of the insulator to the point where the insulator meets the metal shell. The insulator tip is the hottest part of the spark plug, which makes the tip temperature, the main factor in pre-ignition and fouling.

2. Which of the following is not the main part of a spark plug?

a) The center electrode

b) The ground electrode

c) Distributor cap

d) The insulator

Answer: d

Explanation: The spark plug has three main parts, the center electrode, the ground electrode, and the insulator separating them. Besides these, there are the body shell, the sealing ring, and the gasket washer. The distributor cap is not a main part of the spark plug.

3. What is the function of the sealing between the insulator and the body shell?

a) Prevents the hot gas from leaking

b) Prevents the pressure increase

c) Prevents the temperature increase

d) Prevents Current leakage

Answer: a

Explanation: The body shell serves to house the electrodes and the insulator. A gas-tight seal is necessary to prevent the hot gas from leaking between the insulator and the body shell and between the insulator and the center electrode.

4. What is the total resistance in ohms offered by primary winding in the ignition coil?

a) 5

b) 7

c) 3

d) 4

Answer: c

Explanation: The battery winding consists of 200-300 turns of thick wire of total resistance about 3 ohms while the secondary is made up of a large number of turns about 15,000-20,000 of fine wire.

5. Which of the following is used as a material for the body shell of the spark plug?

a) Low carbon steel

b) Ceramic

c) Paper

d) Wood

Answer: a

Explanation: The body shell is generally made of low carbon steel. The body is formed by impact extrusion. The threads are cold rolled to provide a low friction profile. Porcelain was used initially for insulation, but this has a disadvantage of brittleness and low resistance.

6. Which of the following is.used as a material for the ground electrode of the spark plug?

a) Nickel

b) Cast iron

c) Brass

d) Bronze

Answer: a

Explanation: The ground electrode is usually formed of nickel or sometimes an alloy of nickel and manganese. The addition of manganese is about 2.5-3.5 percent which improves the tensile strength and the resistance to the sulfur attack at high temperatures.

7. What is the correct range of gap size in the millimeter of a spark plug?

a) 0.35-0.45

b) 0.6-0.1

c) 1-2

d) 2-4

Answer: b

Explanation: The correct spark plug gap size is specified by the manufacturers varies in general from 0.6 to 1millimeter. For the new spark plug, the gap is generally 0.6 millimeters, but with use it is increased, thus requiring higher voltage for the spark to jump across it.

8. Which of the following material is used to fill the space between the plug electrodes in a surface discharge plug?

a) Semiconductor

b) Plastic

c) Rubber

d) Wood

Answer: a

Explanation: Surface discharge plug is a special type of spark plug where the space between the plug electrodes is filled with some semiconductor material. Thus the spark has to jump across this material instead of air in the ordinary plugs.

9. How is the frequency of firing in a two-stroke concerning the value of four-stroke engines?

a) Same as the value of four-stroke

b) Twice the value of four-stroke

c) Has no relationship with four-stroke

d) Four times the value of four-stroke

Answer: b

Explanation: The frequency of firing in the two-stroke engine is twice the value for four-stroke engines. Therefore expected spark plug life in a motorcycle with two-stroke engines is only half the life in case of cars that always have four-stroke.

10. Which of the following does not affect overheating?

a) Weak mixture

b) Defective cooling system

c) Loose-fitting

d) Engine speed

Answer: d

Explanation: Metallic particle on insulator tip, eroded electrode indicates that the plug as running overheated this may arise due to weak mixture, defective cooling system, loose-fitting causing the exhaust gases to leak.

11. Which among the following is not a requirement of a spark plug?

a) Very high resistance to current leakage

b) Contacts must close without bounce

c) Resistance to corrosion

d) Gas tightness

Answer: b

Explanation: The essential requirements of a good spark plug is to provide very high resistance to current leakage,gas tightness, resistance to corrosion, electrode temperature should be maintained between certain limits.

12. Due to which of the following there are carbon deposits on the spark plug?

a) Overheating of plug

b) Burning of fuel on the plug

c) Erosion of electrodes

d) Engine speed

Answer: b

Explanation: The carbon deposits due to the burning of petrol on the spark plug are recognized by their black color and dry, fluffy nature. The main cause for this is due to a defective fuel system delivering extra rich mixture.

13. Which of the following spark plug increases the resistance to increase the voltage required to jump across the spark plug gap?

a) Rheostat spark plug

b) Wire wound spark plug

c) MOSFET spark plug

d) Resistor spark plug

Answer: d

Explanation: The center electrode contains a built-in resistance in series with the electrode. This resistance also increases the plug life by cutting down peak currents that would burn the electrodes. The resistance increases the voltage required to jump across the spark plug gap. Such plugs are called resistor spark plugs.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “”.

1. What is the percentage of acid and water present in the electrolyte of a lead-acid battery in a fully charged condition?

a) 39% acid and 61% water

b) 45% acid and 65% water

c) 30% acid and 70% water

d) 25% acid and 75% water

Answer: a

Explanation: The electrolyte in a lead-acid battery contains 39 percentage of acid and 61 percentage of water in a fully charged condition. Whereas in the fully discharged condition it contains 85 percentage of water and 15 percentage of acid.

2. Which of the following is the electrolyte used in a lead-acid battery?

a) Nitric acid

b) Sulphuric acid

c) Lead-acid

d) Hydrochloric acid

Answer: b

Explanation: The battery is filled with electrolyte. The electrolyte used in the lead-acid battery is a solution of sulphuric acid. It contains approximately one part of sulphuric acid to two part of water by volume. It should be noted that acid should be added to water and not the vice versa.

3. Which is the active material present on the negative plate in a lead-acid battery?

a) Lead dioxide

b) Lead peroxide

c) Spongy lead

d) Water

Answer: c

Explanation: The positive and negative electrodes of a lead-acid battery are immersed in dilute sulphuric acid. On the positive plate, we have lead peroxide and on the negative plate, the active material is spongy lead.

4. What is the total number of cells present in a 12-volt battery?

a) 5

b) 6

c) 3

d) 4

Answer: b

Explanation: A 12-volt battery consists of six cells connected in series wherein each cell provides 2 volts. One positive and one negative group of plates are sliding over each other. The size of the plates and their number per cell determine the capacity of the battery.

5. Which of the following energy is converted to electricity by the battery?

a) Mechanical energy

b) Chemical energy

c) Thermal energy

d) Electrical energy

Answer: b

Explanation: A battery is a device for storing chemical energy and converting the same into electricity. It supplies current to operate the lighting and various accessories, when the engine is not running, for the starting of the vehicle as well as to ignition system.

6. Which of the following is the material used for separator?

a) Nickel

b) Cast iron

c) Ebonite

d) Bronze

Answer: c

Explanation: To avoid direct contact and thus short-circuiting of positive and negative plates, thin sheets of some no conducting material are inserted between them. These sheets are called as separators. These are made from ebonite, porous rubber, fibreglass etc.

7. What is the correct count of negative plates with respect to positive plates in a battery?

a) Both positive and negative have the same number of plates

b) More positive plates when compared to negative plates

c) More negative plates when compared to positive plates

d) Have no relation between them

Answer: c

Explanation: One positive and one negative group of plates are slid over each other, with separators in between, to form a cell. Most batteries have one more negative plate than positive plates in each cell. The size of plates and their number per cell determine the capacity of the battery.

8. Which of the following material is used in the positive plate of a lead-acid battery?

a) Sulphuric acid

b) Spongy lead

c) Lead peroxide

d) Water

Answer: c

Explanation: When the battery is fully charged there is lead peroxide on the positive plate and lead spongy on the negative plate as an active material. During the process of discharge, the chemical reactions forms lead sulphate on both the plates thereby liberating water.

9. Which of the following increase due to which the electrode gravity decreases?

a) Enthalpy

b) Entropy

c) Temperature

d) Pressure

Answer: c

Explanation: The electrolyte gravity varies with temperature. It increases with the decrease in temperature and vice versa. The gravity value is always mentioned at a specified standard temperature, which is usually 15-degree centigrade.

10. What is the amount of water and acid present in the electrolyte after the full discharge of the battery?

a) 90% of water and 10% of acid

b) 85% of water and 15% of acid

c) 70% of water and 30% of acid

d) 75% of water and 25% of acid

Answer: b

Explanation: The ratio of water and acid in the full discharged state is 85 per cent of water and 15 percentage of acid whereas in the fully charged condition the electrolyte contains 39 percentage of acid and 61 percentage of water.

11. Which among the following colour is used to indicate the positive terminal of the battery?

a) Blue

b) Green

c) Black

d) Red

Answer: d

Explanation: The positive terminal of the battery is coated with red colour and the negative terminal is coated with black colour. During the removal of the battery first, remove the negative terminal and then the positive terminal.

12. Due to which of the following the separator is made porous?

a) To dissipate heat

b) Increases efficiency

c) Allow the diffusion of acid

d) Acts as a pressure relief

Answer: c

Explanation: The material of the separator, apart from being non conducting, must be sufficiently porous or perforated to allow diffusion of the acid. The separator must be slightly thinner than space into which they fit.

13. Which of the following component is formed on the positive plate after the discharged reaction in a lead-acid battery?

a) Sulphuric acid

b) Lead peroxide

c) Lead sulphate

d) Spongy lead

Answer: c

Explanation: During the process of discharge the chemical reactions forms lead sulphate on both the positive and negative plate thereby liberating water. The specific gravity of the electrolyte is lowered. The specific gravity is a good indication of the state of charge of a battery.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Battery Testing”.

1. Which of the following part of a hydrometer which rises and is represented by an arrow below?

a) Rubber bulb

b) Float

c) Sampler tube

d) Glass body

Answer: b

Explanation: The hydrometer is in the form of a glass tubular body with a rubber bulb at the top and a sampler tube at the bottom. There is a glass float inside the glass body. This float has a vertical density scale which when dipped in the electrolyte rises and shown a read off the scale on the surface level of the sample drawn in.

2. Which of the following device is used in the specific gravity test?

a) Cadmium rod

b) Voltmeter

c) Cell voltage tester

d) Hydrometer

Answer: d

Explanation: The battery is filled with electrolyte. The specific gravity test is conducted with the help of a hydrometer. The hydrometer is in the form of a glass tubular body with a rubber bulb at the top and a sampler tube at the bottom. There is a glass float inside the glass body.

3. Which of the following meter is used in the open volt test?

a) Ammeter

b) Voltmeter

c) Galvanometer

d) Hydrometer

Answer: b

Explanation: In the open volt test the state of charge is determined. The open-circuit voltage of a battery cell is measured with the help of an ordinary voltmeter. The open-circuit voltage of a fully charged battery cell is about 2.1 volts.

4. Which of the following test helps in the determination of the chemical condition of positive and negative plates of a battery?

a) Specific gravity test

b) Cadmium test

c) Open volt test

d) High discharge test

Answer: b

Explanation: The cadmium test is conducted to know the chemical condition of the positive and negative plates and is performed only when the battery is either on charge or discharge. In the case of the positive terminal the voltage reading should not be less than 2.5 volts and in case of the negative battery,the terminal should not be more than 0.2 volts.

5. Which of the following is the correct relationship between the voltage of a cell and specific gravity in an open volt test?

a) The voltage of cell=Specific gravity +.840

b) The voltage of cell=Specific gravity -.840

c) Specific gravity =voltage of the cell +12

d) Specific gravity =voltage of the cell -12

Answer: a

Explanation: In an open volt test a change of 0.01 volt of open-circuit voltage is equivalent to a change of 0.010 in the specific gravity of the electrolyte. The relationship between the open-circuit voltage of a battery and its specific gravity is Voltage of the cell =specific gravity +.840.

6. What is the test duration in seconds of a high discharge test when exceeding the time may lead to permanent damage?

a) 5

b) 10

c) 15

d) 20

Answer: c

Explanation: A high discharge test is conducted with the help of a cell voltage tester wherein the voltmeter is connected to two legs with a high resistance placed across them. This test should not be made continuously for more than 15 seconds otherwise the battery plates will get permanently damaged.

7. What is the correct state of the battery during which a high discharge test must be performed?

a) Low load condition

b) Heavy load condition

c) Fully charged state

d) Fully discharge state

Answer: c

Explanation: A high discharge test is made for 10-15 min at the end of which the voltage should not fall below 1.5 volts and the difference of cell voltage of various cells should not exceed 0.2 volts and this test should be made only on fully charged or at least on half-fully charged batteries.

8. Which of the following test does not use a voltmeter?

a) Open volt test

b) Cadmium test

c) High discharge test

d) Specific gravity test

Answer: d

Explanation: Specific gravity test is the only test where a voltmeter is not used instead of a voltmeter a hydrometer is used to determine the specific gravity of the electrolyte. The float inside the hydrometer rises and then the read off the scale at the surface level of the sample drawn in.

9. What is the voltage value in the case of the positive terminal in a cadmium test?

a) Should not be less than 2.5

b) should be less than 1

c) Should be less than 0.5

d) Should not be less than 0.5

Answer: a

Explanation: In a cadmium test the chemical condition of the positive and negative plate is found.In the case of a positive terminal, the voltage reading should not be less than 2.5 volts if the battery is nearing completion of its charge or 2.0 volts if the battery is being discharged at a normal rate.

10. What is the value of the specific gravity of a fully charged battery?

a) 1

b) 1.29

c) 0.5

d) 1.1

Answer: b

Explanation: The specific gravity in many cases is used to find the state of the battery. The specific gravity for a fully charged battery is 1.29 and along with this reading the temperature is also noted accordingly and then compared with the chart supplied by the battery manufacturer.

11. What is the value of the specific gravity of a fully discharged battery?

a) 0.1

b) 1.1

c) 0.5

d) 0

Answer: b

Explanation: The specific gravity is used to find the state of the battery. When the battery has completely discharged the value of the specific gravity reaches a value of 1.1 after which the battery has to be jump-started or replaced if the plates are damaged.

12. What is the value in volts of the negative terminal in the case of the cadmium test?

a) Not more than 0.2

b) more than 0.5

c) Not more than 1

d) More than 1.3

Answer: a

Explanation: In a cadmium test the chemical condition of the positive and negative plates is determined. The reading with the negative battery terminal should not be more than 0.2 volts when the battery is being discharged at a normal rate. A higher reading in this case will indicate defects in negative plates.

13. Which of the following is not a part of the hydrometer apparatus?

a) Ebonite tube

b) Sampler tube

c) Rubber bulb

d) Float

Answer: a

Explanation: The hydrometer is in the form of a glass tubular body with a rubber bulb at the top and a sampler tube at the bottom. There is a glass float inside the glass body. This float has a vertical density scale. Whereas the ebonite tube in use encloses the cadmium rod in the cadmium test.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Battery Charging”.

1. Which of the following is provided to charge the battery constantly?

a) Generator

b) Ignition coil

c) Fuse box

d) Ecu

Answer: a

Explanation: A generator is provided so that it can constantly charge the battery. The rate of charging current flowing from the generator to the battery depends upon the state of charge of the battery. If the battery is run down, the charging rate will be higher, and as it gradually charged the rate tapers off to lower value.

2. Which of the following decreases within turn decreases the charging rate?

a) Temperature

b) Pressure

c) Enthalpy

d) Entropy

Answer: a

Explanation: The main factor affecting charging is the temperature. The charging rate decreases with, a decrease in temperature, and vice versa. That means a battery, at the higher temperature, would take less time for charging, all other conditions remaining the same.

3. Which of the following causes the corrosion of terminals and clamps?

a) Spilled electrolyte

b) Increase in temperature

c) Decrease in pressure

d) Due to high current

Answer: a

Explanation: The corrosion of terminals and clamps is one of the major factors affecting charging. Due to spilled electrolyte and condensation from gases the internal resistance of the battery increases resulting in a decrease in the charging rate.

4. What are the total hours taken by the battery to charge completely?

a) 5-7

b) 7-10

c) 12-20

d) 20-25

Answer: c

Explanation: The battery generally takes from 12-20 hours for recharging a battery depending upon the condition of the battery and the charging rate. However, batteries with sulfate plates require low charging current and hence longer time foe charging.

5. Which of the following is defined as the total capacity of the battery to keep the engine running if the charging system fails?

a) Twenty-hour rate

b) Twenty-minute rate

c) Reserve capacity

d) Cold rate

Answer: c

Explanation: Reserve capacity is an important measurement for the total capacity of the battery. It indicates how long a battery can keep the engine running if the charging system fails. It is the time in minutes for which the battery can supply 25amps.

6. Which of the following is the abbreviation of CCA?

a) Cold-cranking amperes

b) Crankcase accumulation

c) Crankcase alternator

d) Cold-cranking accumulation

Answer: a

Explanation: The abbreviation of CCA is cold cranking amperes. The CCA rating of an automobile battery must equal or exceed the number of cubic inches of engine displacement. The temperature of the cold rate or CCA of the battery at the beginning of discharge is kept -18 degrees centigrade.

7. How is the rate of charging if there are impurities in the electrolyte?

a) Same

b) Increase

c) Decrease

d) Remains the same and decreases as time goes

Answer: c

Explanation: The important factor affecting the charging rate is the impurities present in an electrolyte. The electrolyte impurities decrease the charging rate. Apart from the impurities, gassing also decreases the charging rate of the battery.

8. How many minutes can a battery of two-minute rate supply before the voltage dropping below 1.5volts?

a) 80

b) 60

c) 20

d) 40

Answer: c

Explanation:Twenty-minute rate of a battery represents the rate of current a battery can deliver continuously for 20 minutes, the cell voltage not dropping below 1.5. The temperature of the battery at the start of the test is brought to 80 degrees.

9. Which are the gasses that get precipitated in the form of bubbles when the battery is overcharged?

a) Hydrogen and helium

b) Nitrogen and hydrogen

c) Hydrogen and oxygen

d) Nitrogen and oxygen

Answer: c

Explanation: The major factor affecting the charging is gassing wherein excessive hydrogen and oxygen bubbles due to overcharging may wash away active material on the plates, decreasing the charging rate. Due to which overcharging must be avoided.

10. Which of the following has no effect on overheating?

a) Weak mixture

b) Defective cooling system

c) Loose-fitting

d) Engine speed

Answer: d

Explanation: Metallic particle on insulator tip, eroded electrode indicates that the plug as running overheated this may arise due to weak mixture, defective cooling system, loose-fitting causing the exhaust gases to leak.

11. Which among the following is not a factor affecting the charging of the battery?

a) State of charge

b) Gassing

c) Temperature

d) Discolouring of electrolyte

Answer: d

Explanation: The factors affecting the charging of a battery are temperature, area of the plate, state of charge, gassing, impurities, corrosion of terminal, and clamps whereas the discoloring of the electrolyte has no effect of charging of the battery.

12. Which of the following converts the 3Phase AC current flowing from the alternator and charges the battery with DC current as shown below?

a) Transformer

b) Rectifier

c) Alternator

d) Battery

Answer: b

Explanation: The alternator produces 3 phase AC current which cannot be directly supplied to the battery which operates on DC current therefore a rectifier consisting of 3 diodes rectifies this 3 phase according to DC and charges the battery.

13. Which of the following helps in the identification of the state of the battery?

a) Latent heat of vaporization

b) Entropy

c) Latent heat of the cooling

d) Specific gravity

Answer: d

Explanation: The state of the battery charge is checked most commonly by the specific gravity. The temperature is also recorded and the gravity reading is corrected accordingly. This is then compared with the chart supplied by the battery manufacturer to ascertain whether the battery needs to be charged or not.

This set of Automotive Engine Auxiliary Systems written test Questions & Answers focuses on “Battery Troubles”.

1. By how much variation in the gravity points cell gravity variation can be found?

a) 9

b) 5

c) 10

d) 6

Answer: c

Explanation: Cell gravity variation is one among the other battery troubles during the cell gravity variation the gravity readings of all the cells should be the same. If the reading of some cells is different from the rest by more than 10 gravity points, it indicates the loss of acid from a cell.

2. To avoid which of the following the water level in the electrolyte should be checked periodically?

a) To control the temperature

b) To control the pressure

c) To avoid the damage of the separator and plates

d) To avoid the damage of the electrodes

Answer: c

Explanation: The water in the electrolyte keeps on evaporating and periodic checks must be made to ensure that proper level and gravity is being maintained. If this is not done, the separators and the plate may be permanently damaged.

3. Which is the liquid that is used in the cleaning of the battery terminals and clamps to avoid corrosion?

a) Hydrochloric acid

b) Dilute sulphuric acid

c) Liquid ammonia

d) Liquid nitrogen

Answer: c

Explanation: Due to oxidation the battery terminals and the clamp must be cleaned after regular intervals. After cleaning with a cloth moistened with liquid ammonia, a coat of petroleum jelly helps to retard their corrosion again.

4. Which of the following is not a cause for deterioration of plates?

a) The high specific gravity of the electrolyte

b) Freezing of electrolyte

c) Mechanical damage to the battery

d) The proper mixture of water and acid

Answer: c

Explanation: The deterioration of plates may be caused by any of the following like very high charging or discharging rate, the high specific gravity of the electrolyte, freezing of electrolyte, mechanical damage due to rough ride whereas as the proper mixture of acid and water slows down the deterioration of plates.

5. Which of the following is not a reason for the self-discharge of the battery?

a) Contamination of electrolyte

b) Damaged separators

c) Long term storage

d) Use of distilled water for electrolyte

Answer: d

Explanation: The main cause for self-discharging of the battery are contamination of the electrolyte, damaged separators and long time storage. By using pure sulphuric acid and distilled water for preparing electrolyte helps in the life of the battery.

6. Which of the following increases due to a reduction in the capacity of battery plates due to sulphation?

a) Pressure

b) Internal resistance

c) Temperature

d) Enthalpy

Answer: b

Explanation: Large lead sulphate crystals, whitish in colour are formed on the plates. These crystals are difficult to be converted back into active materials on recharging. Sulphation of the battery reduces the capacity and increases the internal resistance of the cells.

7. Which of the following is the result of long term storage of the battery?

a) Low load

b) variation in pressure

c) Variation in enthalpy

d) Stratification

Answer: d

Explanation: Stratification is one of the battery troubles. Long term storage of the battery causes stratification of the electrolyte, for example, the bottom layer becomes heavier than the top layers. Such stratification sets up local equalising currents which increase the self-discharge rate.

8. In which type of battery there is no requirement of any water during normal service?

a) Lead-acid

b) Lithium-ion

c) Lead-cadmium grid

d) Zinc-air

Answer: a

Explanation: In the lead-cadmium grid battery does not require any water to be added during normal service, as excessive water loss may be caused due to higher than normal charging rate due to incorrect setting of the regulator.

9. Which of the following is the reason for the discolouring of electrolyte?

a) Improper water and acid in the electrolyte

b) Plates are disintegrating

c) No proper vent plugs

d) Freezing material in the electrolyte

Answer: b

Explanation: Discolouring of electrolyte is one of the battery troubles. The discolouring of the electrolyte is an indication that the plates are disintegrating and the battery has almost exhausted its life.

10. Which among the following damage leads to internal short-circuiting?

a) Separator

b) Post strap

c) Vent plug

d) Container

Answer: a

Explanation: The internal short-circuiting is caused by either damaged separators or when the active material dropping from the plate forms itself into a heap so high as to cause short-circuiting. It results in rapid self-discharge and sulphation.

11. Which of the following is not a precaution to avoid sulphation?

a) Proper electrolyte level

b) Proper specific gravity

c) Rapid discharging

d) Proper water addition

Answer: c

Explanation: The battery which is not excessive sulphates can be recharged keeping the charging rate low. The precautions to avoid sulphation are the battery water level should be checked, and the electrolyte level and gravity level should be maintained at the proper value and heavy discharge of battery should be avoided.

12. Which of the following lead to the bulged case of a battery?

a) Loss of water

b) Internal short-circuiting

c) Sulphation

d) Overcharging

Answer: d

Explanation: The main trouble a faces is bulged case which because of overcharging of the battery to avoid overcharging the regulated voltage must be reduced. And the clamps should not be too tight and the temperature of the battery should be maintained.

13. Which of the reason for cracking of the battery container as shown below?

a) Mechanical shocks and jolts

b) High-pressure relief

c) Temperature difference

d) Variation in voltage

Answer: a

Explanation: The container develops cracks generally due to mechanical shocks caused by rough roads jolts or rough handling. If the cracks are on the outer walls, the electrolyte will leak. Cracks on the interior cause internal short-circuiting of the plates of the two adjoining cells.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Lithium-Ion Battery”.

1. Which of the following as shown below avoids the direct contact of the positive and negative plate in a lithium-ion battery?

a) Electrolyte

b) Separator

c) Load

d) Rectifier

Answer: b

Explanation: The separator avoids the direct contact and thus short-circuiting of positive and negative plates, thin sheets of some non-conducting material are inserted between them. These sheets are called as separators.

2. Which is the electrolyte used in Li-ion battery?

a) Lead dioxide

b) Lithium-based gel

c) Sulfur dioxide

d) Cobalt

Answer: b

Explanation: Lithium-ion batteries also work by shuttling ions between the electrode. During charging, ions travel in one direction; during the discharging process, they go in the other direction. The electrolyte is a lithium-based gel or polymer.

3. Which of the following statement is true for the movement of electrons concerning the direction of current?

a) Same as the direction of current

b) Opposite direction of current

c) Does not depend on the direction of current

d) No movement of electrons

Answer: b

Explanation: During the charging mechanism of lithium-ion battery the current flows from the anode to the cathode whereas the electrons present in the cathode move from cathode to anode thus the movement of the electrons is opposite when compared to the direction of current flow.

4. Which is the material used to as anode in a lithium-ion battery?

a) Brass foil coated with graphite

b) Aluminum foil coated with graphite

c) Copper foil coated with graphite

d) Stainless steel coated with graphite

Answer: b

Explanation: The Lithium-ion battery having round Li-ion cells employ anodes of aluminum foils coated with graphite and is soaked with an organic electrolyte, which enables the transfer of lithium ions in the first place.

5. Which of the following is not a disadvantage of a lithium-ion battery?

a) Complex to manufacture

b) Sophisticated chargers

c) More expensive

d) High energy density

Answer: d

Explanation: The disadvantages of a lithium-ion battery are it is more expensive,since these are more complex to manufacture. These require a sophisticated charger to carefully monitor the charging process which makes it more complex. Whereas high energy density is the advantage of the lithium-ion battery.

6. Which of the following is formed at the graphite electrode during the charging process of a battery when the lithium-ion move through the separator?

a) Water

b) Graphite

c) Lithium hydroxide

d) Lithium carbide

Answer: d

Explanation: During the charging process, lithium ions are released from the metal oxide and move through the separator to the graphite electrode where lithium carbide is formed. The energy stored in the charging process can be released again by the inverse chemical reaction.

7. What is the range of specific energy in Watt-hour per kg in a lithium-ion battery?

a) 0-50

b) 100-265

c) 50-60

d) 60-100

Answer: b

Explanation: Lithium-ion battery has a promising future as a rechargeable battery for the electric hybrid vehicle due to its very high storage capacity,which ranges from 100-265 watt-hour per kg with the fact that it operates at room temperature.

8. Which is the material used as a cathode in a lithium-ion battery?

a) Zinc foils coated lithium metal oxide

b) Brass foil coated with graphite metal oxide

c) Aluminum foils coated with graphite metal oxide

d) Copper foils coated with lithium metal oxide

Answer: c

Explanation: The lithium-ion batteries having round Li-ion cells employ anode of aluminum foils coated with graphite and cathodes of copper foils coated with lithium metal oxide. The wound electrodes are soaked with an organic electrolyte.

9. What is the maximum storage temperature in degree centigrade of a Li-ion battery?

a) 30

b) 50

c) 60

d) 40

Answer: c

Explanation: Lithium-ion batteries should not be stored at temperatures above 60 degrees centigrade and operated at above 40 degrees centigrade. Likewise there is an appreciable reduction in the potential charging and discharging rate below -5 degrees centigrade.

10. Which of the following is not an advantage of Lithium-ion battery?

a) High specific energy density

b) More expensive

c) Reliability

d) Lower self-discharge rate

Answer: b

Explanation: The lithium-ion battery has many advantages like higher specific energy density than most other types,lower self-discharge rate, has much greater reliability whereas the disadvantage of the li-ion battery is that it is more expensive,since complex to manufacture.

11. Which of the following material is used as separator material in Lithium-ion battery?

a) Brass

b) Metal sheet

c) Paper

d) Plastic

Answer: d

Explanation: The lithium-ion battery employ anodes of aluminum foils coated with graphite and cathodes of copper foils coated with lithium metal oxide. A.plastic separator separates the anode and the cathodes. The wound electrode is soaked with an organic electrolyte.

12. Which of the following circuit is used for cooling of the lithium-ion battery?

a) Air conditioning

b) Heater circuit

c) Ignition circuit

d) EGR circuit

Answer: a

Explanation: For cooling, the heat from the battery can be dissipated only through the air conditioning circuit. The battery heat from the refrigerant circuit of the air conditioning system can be transferred,using conditioned air, a dedicated coolant circuit.

13. What is the maximum operating temperature in degree centigrade above which the lithium-ion battery should not be operated?

a) 10

b) 20

c) 30

d) 40

Answer: d

Explanation: Li-ion batteries have a maximum operating temperature should not be above 40-degree centigrade. Operating the Li-ion battery beyond this temperature range shortens the battery life due to irreversible damage occurring within the Li-ion cells.

This set of Basic Automotive Engine Auxiliary Systems Questions and Answers focuses on “Starting System”.

1. What is the voltage required for starting a car engine?

a) 12V

b) 9W

c) 24V

d) 32V

Answer: a

Explanation: The rated voltage for the starting system, which is 12V in case of a car engine and 24V for heavy vehicle engines. Car engine parts require less power to move. Hence, 12V is used.

2. What is the voltage required for starting a heavy vehicle engine?

a) 12V

b) 9W

c) 24V

d) 32V

Answer: c

Explanation: The rated voltage for the starting system, which is 12V in case of a car engine and 24V for heavy vehicle engines. Heavy vehicle engine parts require a lot of power to move. Hence, 24V is required.

3. In cars, what is the lowest temperature at which the car engine may be started?

a) -15°C to -20°C

b) -18°C to -25°C

c) 8°C to 25°C

d) -8°C to -5°C

Answer: b

Explanation: The lowest temperature at which the car engine may be started is usually taken as -18°C to -25°C for cars and -15°C to -20°C for heavy transport vehicles. The lowest temperature Includes the snowy regions.

4. Calculate the total number of turns for a square and ground end when N=13?

a) -15°C to -20°C

b) -18°C to -25°C

c) 8°C to 25°C

d) -8°C to -5°C

Answer: a

Explanation: The lowest temperature at which the car engine may be started is usually taken as -18 o C to -25 o C for cars and -15 o C to -20 o C for heavy transport vehicles.

5. Which of the mentioned below is not a component of a starting motor?

a) Armature

b) Commuter

c) Field windings

d) Battery

Answer: d

Explanation: The main components of a starting motor are the body, the armature, the commuter, and the field winding. Whereas battery is a separate component used as a power source for the motor.

6. Most of the automotive starting motors have how many poles?

a) 3

b) 4

c) 5

d) 6

Answer: b

Explanation: Most of the automotive starting motors have 4 poles and 4 brushes. The brushes are held against the commuter using springs. Pole refers to the north or south pole of the magnet.

7. Most of the automotive starting motors have how many brushes?

a) 3

b) 4

c) 5

d) 6

Answer: b

Explanation: Most of the automotive starting motors have 4 poles and 4 brushes. The brushes are held against the commuter using springs. The brushes depend on the power and winding of the motor.

8. What is the starting torque of the starting motor for a light and medium car?

a) 10 to 30Nm

b) 50-150Nm

c) 40 to 15Nm

d) 5 to 10Nm

Answer: a

Explanation: For light and medium cars, the starter motors of starting 10 to 30Nm are employed, whereas for larger cars and heavy vehicles the starting torques required are 50 to 150Nm.

9. What is the starting torque of the starting motor for heavy vehicles?

a) 10 to 30Nm

b) 50-150Nm

c) 40 to 15Nm

d) 5 to 10Nm

Answer: b

Explanation: For light and medium cars, the starter motors of starting 10 to 30Nm are employed, whereas for larger cars and heavy vehicles the starting torques required are 50 to 150Nm. Heavy vehicle engines have heavier components. Hence, to move them higher torque is required.

10. What is the minimum cranking speed required for starting an engine in the winter condition?

a) 100rps

b) 10rpm

c) 100rpm

d) 50rps

Answer: c

Explanation: It is found that on the modern car engine the minimum cranking speed of 100rpm is adequate even in adverse winter conditions. Hence, 100rpm is the right answer.

11. On what factor, the speed ratio between the starting motor and the crankshaft is depended?

a) Teeth on flywheel

b) Piston

c) Size of flywheel

d) Crankshaft

Answer: c

Explanation: The speed ratio between the starting motor and the crankshaft depends on the Size of the flywheel, which is further dictated by engine design consideration.

12. On what factors, the starting torque is dependent?

a) Piston displacement per cylinder

b) Number of cylinders

c) All of the mentioned

d) Compression pressure

Answer: c

Explanation: The starting torque of the starter motor depends on piston displacement per cylinder, number of cylinders, and the Compression pressure. Hence, all of the mentioned is the right answer.

13. What is the highest current that is drawn by the starter motor?

a) 50amps

b) 230amps

c) 500amps

d) 1000amps

Answer: c

Explanation: The starter motor is directly connected to the battery from where it draws the current for its operation. The amount of current drawn for starting may be as high as 500amperes.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “ Starting System – Bendix Drives”.

1. Which are the two types of Bendix drives?

a) Inboard and outboard

b) Inboard and onboard

c) Onboard and outboard

d) Onboard and bottom board

Answer: a

Explanation: Inboard and outboard are the two types of Bendix drives. In the outboard type pinion moves away from the starting motor to engage the flywheel whereas in the inboard type it moves towards the starting motor.

2. In outboard type, the pinion moves which side to the starting motor?

a) Up

b) Towards

c) Away

d) Downward

Answer: c

Explanation: Inboard and outboard are the two types of Bendix drives. In the outboard type pinion moves away from the starting motor to engage the flywheel whereas in the inboard type it moves towards the starting motor.

3. In inboard type, the pinion moves which side to the starting motor?

a) Up

b) Towards

c) Away

d) Downward

Answer: b

Explanation: Inboard and outboard are the two types of Bendix drives. In the outboard type pinion moves away from the starting motor to engage the flywheel whereas in the inboard type it moves towards the starting motor.

4. The sleeve can slide or turn freely over which part of the motor?

a) Shaft

b) Body

c) Commuter

d) Armature

Answer: a

Explanation: The sleeve can slide or turn freely over the shaft of the motor and the shaft is keyed to the fixed down head which is connected torsionally to the sleeve through a coil spring.

5. The lock pin comes out of the detent due to which force?

a) Normal force

b) Centripetal force

c) Shear force

d) Centrifugal force

Answer: d

Explanation: The lock pin comes out of the detent due to centrifugal force which overcomes the spring force. The pinion then gets disengaged as in the case of the standard Bendix drives.

6. Which pin is loaded with a spring which is stiffer than the spring of lock-pin?

a) Race pin

b) Anti-drift pin

c) Circlip pin

d) Roll pin

Answer: b

Explanation: The Anti-drift pin is loaded with a spring that is stiffer than the spring of lock-pin. This prevents the drifting of the pinion to engage with the flywheel.

7. When the motor is started, the sleeve starts rotating along with which part of the motor?

a) Windings

b) Armature shaft

c) Poles and brushes

d) Commuter

Answer: b

Explanation: When the motor is started, the sleeve starts rotating along with the armature shaft of the motor. A spring under compression is employed in between the sleeve and the nut which is fixed on the end of the armature shaft.

8. When pinion gear starts to rotate, which part offers initial resistance?

a) Flywheel

b) Crankshaft

c) Connecting rod

d) Springs

Answer: a

Explanation: When the pinion gear starts to rotate, it is offered by an internal resistance by the flywheel which is stationary when the vehicle is in a standstill position.

9. Which type of Bendix drive is used to avoid the damage caused due to a false engine starting?

a) Overrunning clutch

b) Rubber spring

c) Compression type

d) Folo-thru

Answer: b

Explanation: Rubber spring Bendix drive is used to avoid the damage caused due to false engine starting the piston gets disengaged and an attempt is made to bring it back.

10. Dyer Bendix drive is used in which type of vehicle?

a) Cars

b) Bikes

c) Heavy-duty vehicle

d) Light-duty vehicle

Answer: c

Explanation: Dyer Bendix drive is used in the Heavy-duty type of vehicle, it is designed to complete engagement of the pinion with the flywheel gear.

11. In Dyer Bendix drive, the spiral teeth have which type of motion?

a) Linear motion

b) Colinear motion

c) Angular motion

d) Perpendicular motion

Answer: c

Explanation: When the shift sleeve is pushed to the right and consequently the pinion is also moved in that direction, because of the spiral teeth, there is angular motion.

12. The shell is connected with the armature shaft through splines and the collar is attached to which part?

a) Collar

b) Key

c) Pinion

d) Spigot

Answer: c

Explanation: The shell is connected with the armature shaft through splines and the collar is attached to Pinion of the starting motor to start the vehicles.

13. Lubrication causes the dirt to accumulate on the sleeve and which part?

a) Spigot

b) Collar

c) Pinion

d) Key

Answer: c

Explanation: Lubrication causes the dirt to accumulate on the sleeve and pinion teeth which cause sticking of pinion and inertia drives are that the pinion and the sleeve should not be lubricated.

This set of Automotive Engine Design Multiple Choice Questions & Answers focuses on “Starting Motor Switches and Control Circuit”.

1. The switch should be able to withstand how much current?

a) 150 to 500 amp

b) 5 t0 30 amp

c) 10 to 100amp

d) 600 to 1000amp

Answer: a

Explanation: Starting motor takes from 150 to 500 amps while starting the engine and as such the switches operation must be capable of taking this much current with minimum voltage drop.

2. To obtain more positive operation of the solenoid, what is used along with the solenoid shift?

a) Limit switch

b) Manual switch

c) Relay

d) Toggle switch

Answer: c

Explanation: The engagement of pinion with the flywheel is done with a solenoid switch-cum shift, commonly referred to as a solenoid shift only.

3. Manual switches are operated by which of the below-mentioned mode?

a) Hand

b) Foot

c) accelerator lever

d) All of the mentioned

Answer: d

Explanation: Here the plunger is pressed to make contacts and contacts are made by hand, foot, accelerator lever. Manual switches are less dangerous than electronic switches in the condition of sudden power failure.

4. What is Solenoid switch is also known as?

a) Magnetic switch

b) Electric switch

c) Electro-magnetic switch

d) Manual switch

Answer: a

Explanation: Solenoid switch is also known as a magnetic switch, as the button is pressed the current flows from the battery to the windings which produces a magnetic field.

5. The reduction in heavy current wiring length is the advantage of which type of switch?

a) Relay

b) Electro-magnetic switch

c) Manual switch

d) Solenoid switch

Answer: d

Explanation: The advantage of the solenoid switch when compared to manual switch is that the heavy current wiring length is reduced, which reduces the voltage drop.

6. The pull-in and hold-in windings exert force on which part?

a) Commuter

b) Armature

c) Poles

d) Brushes

Answer: b

Explanation: The solenoid switches have two winding, pull-in, and hold-in windings. Both the windings exert combined force to pull the armature.

7. What is the main advantage of the solenoid switch?

a) More current is induced

b) Less current drawn from the battery

c) More resistance

d) More resistance and current is induced

Answer: b

Explanation: The advantage of the solenoid switch is it draws less current in Hold-in winding when it remains to hold the contacts closed. Hence, Less current drawn from the battery is the right answer.

8. The solenoid switch come-shift must have how many windings?

a) 2

b) 1

c) 4

d) 8

Answer: a

Explanation: The solenoid switch come-shift has got a different plunger construction suited for operating the shift lever. Further, this is of 2 winding types, the solenoid shift must always have two windings.

9. What is the use of a relay?

a) To control the magnetic field

b) To control solenoid currents

c) To control Eddy current

d) To control both the magnetic field and eddy current

Answer: b

Explanation: The relay used to control the solenoid currents. Further, completing the relay circuit through the generator provides protection against the operating of the starter.

10. The Generator voltage is approximately equal to which voltage?

a) Stater motor voltage

b) Engine power

c) Battery voltage

d) Dynamo voltage

Answer: c

Explanation: The relay circuit through the generator provides protection against the operating of the starter while the engine is running because the generator voltage is approximately equal to Battery voltage.

11. What is the minimum cranking speed for a reciprocating S.I engine?

a) 150-180rpm

b) 60 to 140rpm

c) 60-90rpm

d) 100-200rpm

Answer: c

Explanation: The minimum cranking speed for a reciprocating S.I engine is 60-90rpm, for the rotary engine it is 60-90rpm and for the C.I engine with glow plugs is 60-140rpm.

12. What is the minimum cranking speed for a rotary S.I engine?

a) 150-180rpm

b) 60 to 140rpm

c) 60-90rpm

d) 100-200rpm

Answer: a

Explanation: The minimum cranking speed for a reciprocating S.I engine is 60-90rpm, for the rotary engine it is 150-180rpm. Rotary engines are the high-speed engine that are rarely used in race cars.

13. What is the minimum cranking speed for a C.I engine with glow-plugs?

a) 150-180rpm

b) 60 to 140rpm

c) 60-90rpm

d) 100-200rpm

Answer: b

Explanation: The rotary engine it is 150-180rpm and for the C.I engine with glow plugs is 60-140rpm.Glow plugs are the engine heaters that are used to increase the engine temperature.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Testing the Starting System”.

1. Which device is used to check the current?

a) Ammeter

b) Voltmeter

c) Galvanometer

d) Odometer

Answer: a

Explanation: The device used to check the current is the ammeter and the device used to check the voltage is the voltmeter, the galvanometer is used to detect and indicate electric current.

2. Which device is used to check the voltage?

a) Ammeter

b) Voltmeter

c) Galvanometer

d) Odometer

Answer: b

Explanation:The device used to check the voltage is the voltmeter and the device used to check the speed is the odometer, the device used to check the RPM is the tachometer.

3. Continuity in the field windings can be tested in which device?

a) Voltmeter

b) Multimeter

c) Galvanometer

d) Ammeter

Answer: b

Explanation: Continuity should exist in the field windings which may be tested with a multimeter. There should also be perfect insulation between the yoke and the field.

4. If there is a wear or damage is more than the permissible limits, what has to be done?

a) Replace the brushes

b) Grind the brushes

c) Skim the brushes

d) Mill the brushes

Answer: a

Explanation: Examine the brushes visually for wear and damage, if the wear or damage is more than the permissible limits, replace the concerned brushes.

5. In the case of shift, it must be noted that the test should not be continued for more than how many seconds?

a) 31-40min

b) 5-7sec

c) 30-55min

d) 10-15seconds

Answer: d

Explanation: In the case of shift, it must be noted that the test should not be continued for more than 10-15 seconds. Disconnect the lead wire connecting the switch to the starter motor.

6. Which accessory in the car is used to indicate the working condition of starter motor?

a) Speaker

b) Light

c) Alternator

d) Battery

Answer: b

Explanation: The lights in the car are used to indicate the working condition of the starter motor, lights may go off, it might get dim or it is unaffected all this indicates the problem of the starter motor.

7. Lights go off completely, what does this indicate concerning Starter motor?

a) Low battery power

b) Loose connection

c) Open circuit in the field winding

d) Defective starter motor

Answer: b

Explanation: This is due to some loose connection in the circuit, most likely near the battery. This may be located and rectified accordingly by tightening the nut and checking the wire.

8. Lights get dim heavily, what does this indicate concerning Starter motor?

a) Weak battery

b) Loose connection

c) Open circuit in the field winding

d) Defective starter motor

Answer: a

Explanation: This problem is due to a weak battery and the solution is the battery has to be recharged or it has to be replaced with a new battery. The battery used in automobiles is a lead-acid battery.

9. Lights dim but slightly, what does this indicate concerning Starter motor?

a) Weak battery

b) Loose connection

c) Open circuit in the field winding

d) Defective starter motor

Answer: c

Explanation: This problem is due to an open circuit in the field winding or the armature of the starting motor, this can be tested accordingly and fix the issue.

10. Lights remain unaffected, what does this indicate concerning Starter motor?

a) Weak battery

b) Loose connection

c) Open circuit in the field winding

d) Defective starter motor

Answer: c

Explanation:This problem is due to the open circuit, the wiring of every component has to be tested individually and the defective component has to be replaced.

11. In modern starters, the pole shoes are replaced with which component?

a) Titanium coil

b) Carbon brushes

c) Permanent magnet

d) Electro-magnet

Answer: c

Explanation: In modern starters, the conventional field windings and the pole shoes are replaced with permanent magnets. Hence permanent magnets are the right answer.

12. How is the drive system between the engine and gearbox in modern starter motor?

a) Shaft drive

b) Belt drive

c) Belt drive or connected directly to the flywheel

d) Connected directly to the flywheel

Answer: c

Explanation: It can be the belt-driven or connected directly to the flywheel between the engine and the gearbox. The former needs less amount of copper and iron.

13. What is the minimum cranking speed for a C.I engine without glow-plugs?

a) 150-180rpm

b) 60 to 140rpm

c) 60-90rpm

d) 100-200rpm

Answer: d

Explanation: The minimum cranking speed for a reciprocating S.I engine is 60-90rpm, for the rotary engine it is 150-180rpm and for the C.I engine without glow plugs is 100-200rpm.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Fuels – Refining of Crude Oil”.

1. Crude oil is subjected to which distillation process?

a) Fractional distillation

b) Steam distillation

c) Simple distillation

d) Zone distillation

Answer: a

Explanation: Crude oil distillation is done in the Fractional column. Crude oil is heated to about 400 o C in a fractional distillation column. Above this temperature, different fuels like petrol, diesel, and kerosene are extracted.

2. Crude is heated to about what temperature?

a) 100°C

b) 300°C

c) 400°C

d) 1000°C

Answer: c

Explanation: Crude oil is heated to about 400°C in a fractional distillation column andthe fraction obtained in the fractionating column is in the range of about 70° to 120°C and is known as straight-run gasoline.

3. Straight run gasoline in the fractional column is obtained at what temperature?

a) 135°C to 170°C

b) 70° to 120°c

c) 8°C to 25°C

d) 130°C to 150°C

Answer: b

Explanation: The fraction obtained in the fractionating column is in the range of about 70° to 120°c and is known as straight-run gasoline. The vaporized crude oil is again passed through the heater and vacuum to obtain heavy gas oils and lubricating oils.

4. What is obtained when the vaporized crude oil is again passed through the heater and vacuum?

a) Heavy gas oils

b) lubricating oils

c) Petrol

d) Both heavy gas oils and lubricating oils

Answer: a

Explanation:. The vaporized crude oil is passed through the heater and vacuum to obtain heavy gas oils and lubricating oils. Heavy gas oils have higher pressure and temperature and burn completely.

5. Which of the mentioned below not a process of obtaining gasoline?

a) Cracking

b) Polymerization

c) Alkylation

d) Casting

Answer: d

Explanation: Cracking, Polymerization, and alkylation are all the processes involved in the extraction of gasoline whereas casting is the process related to metal.

6. What is the octane number of the gasoline obtained by thermal cracking?

a) 93

b) 75

c) 58

d) 60

Answer: b

Explanation:The octane number of the gasoline obtained by thermal cracking is 75, 1-3MPa the pressure maintained during the process of thermal cracking and 500 o C is the temperature maintained during the thermal cracking process.

7. What is the pressure maintained during the process of thermal cracking?

a) 10-13Mpa

b) 1-3MPa

c) 0.1-0.5MPa

d) 6-7MPa

Answer: b

Explanation: The octane number of the gasoline obtained by thermal cracking is 75, 1-3MPa the pressure maintained during the process of thermal cracking and 500 o C is the temperature maintained during the thermal cracking process.

8. What is the temperature maintained during the thermal cracking process?

a) 500 o C

b) 400 o c

c) 300 o C

d) 200 o C

Answer: a

Explanation: The octane number of the gasoline obtained by thermal cracking is 75, 1-3MPa the pressure maintained during the process of thermal cracking and 500 o C is the temperature maintained during the thermal cracking process.

9. In which type of Cracking, aluminum silicates,or natural clay is used?

a) Thermal cracking

b) Catalytic cracking

c) Hydrogen cracking

d) Polymerized cracking

Answer: b

Explanation: Catalytic cracking is the improved form of thermal cracking wherein catalyst is used to promote cracking and aluminum silicate or natural clay is the catalyst.

10. Which process is used to improve the anti-knock qualities of gasoline?

a) Cracking

b) Alkylation

c) Reforming

d) Hydrogenation

Answer: c

Explanation:The reforming process is used to improve the anti-knock qualities of gasoline.In the process of reforming, the straight-chain paraffin and naphthenes are converted to aromatic hydrocarbons.

11. In the process of reforming, the straight-chain paraffin and naphthenes are converted to what?

a) Branched hydrocarbons

b) Isometric hydrocarbons

c) Aromatic hydrocarbons

d) Alkene hydrocarbons

Answer: c

Explanation: In the process of reforming, the straight-chain paraffin and naphthenes are converted to aromatic hydrocarbons.Straight chain hydrocarbons are stable when compared to branched hydrocarbons.

12. Which process is used to combine lighter hydrocarbons to higher hydrocarbons?

a) Alkylation

b) Hydrogenation

c) Polymerization

d) Reforming

Answer: c

Explanation: Polymerization is the process used to combine lighter hydrocarbons to higher hydrocarbons and sulphuric acid or hydrochloric acid is used as a catalyst in alkylation.

13. Which catalyst is used in Alkylation?

a) Sulphuric acid

b) Hydrochloric acid

c) Sulphuric acid or hydrochloric acid

d) Di-chloric acid

Answer: c

Explanation:Polymerization is the process used to combine lighter hydrocarbons to higher hydrocarbons and sulphuric acid or hydrochloric acid is used as a catalyst in alkylation. Catalysts doesn’t change the reaction but fasten the rate of reaction.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Properties of Conventional Fuels”.

1. The fuel should have high anti-knock value to make use of what?

a) Higher compression ratio

b) Lower compression ratio

c) Higher noise

d) Higher knock

Answer: a

Explanation: Volatility indicates the tendency of the fuel to change from liquid to vapor form, and the fuel should have high anti-knock value to make use of a Higher compression ratio.

2. Which property indicates the tendency of the fuel to change from liquid to vapor form?

a) Knock rating

b) Calorific value

c) Volatility

d) Gum content

Answer: c

Explanation: Volatility indicates the tendency of the fuel to change from liquid to vapor form. Higher the value of volatility, the more the combustion takes place. So the fuel should have more volatility for complete combustion.

3. What is the approximate calorific value of the gasoline?

a) 1-28MJ/Kg

b) 38-48MJ/Kg

c) 50-70MJ/Kg

d) 57-68MJ/Kg

Answer: b

Explanation: The fuel should have a high calorific value. However, it is seen that for the different grade, gasoline have approximately the calorific value of 38-48MJ/Kg.

4. Some of the Sulphur content in the fuel forms which compound?

a) Corrosive compound

b) Crystal compound

c) Amorphous compound

d) Both crystal and amorphous

Answer: a

Explanation: A high Sulphur content is undesirable. Some of the Sulphur compounds restrict the action of lead and some fuel forms Corrosive compound.

5. The aromatic content in the fuel has corrosive action of the rubber in fuel and has what?

a) Low boiling point

b) High boiling point

c) Low melting point

d) High freezing point

Answer: d

Explanation: Aromatics are high knock rating hydrocarbons, the aromatic content in the fuel has corrosive action of the rubber in fuel and has High freezing point.

6. What does CNG stand for?

a) Common natural gas

b) Compressed natural gas

c) Common nitrogen gas

d) Compressed nitrogen gas

Answer: b

Explanation: LPG stands for Liquefied petroleum gas; LNG stands for Liquefied natural gas and CNG stands for Compressed natural gas. Hence, Compressed natural gas is the right answer.

7. What does LNG stand for?

a) Lithium nitrogen gas

b) Liquefied natural gas

c) Lithium natural gas

d) Liquefied nitrogen gas

Answer: b

Explanation: LPG stands for Liquefied petroleum gas, LNG stands for Liquefied natural gas and CNG stands for Compressed natural gas. Hence, Liquefied natural gas is the right answer.

8. What does LPG stand for?

a) Liquefied petroleum gas

b) Lithium petroleum gas

c) Liquefied potash gas

d) Lithium potash gas

Answer: a

Explanation: LPG stands for Liquefied petroleum gas, the petroleum gas is compressed at a very high temperature and pressure to obtain it in liquid form, and then it is stored in the container.

9. What does M85/E15 represent?

a) 85% methylene and 15%ethlyene

b) 85% methanol and 15% ethanol

c) 85% methyl and 15%ethyl

d) 85% methyl and 15%ethlyene

Answer: b

Explanation: M85/E15 represents that the mixture of gasoline contains 85% methanol and 15% ethanol. Methanol and Ethanol are two main constituents is gasoline.

10. Which of the mentioned below is not a material of Bio-fuel?

a) Soya bean

b) Rapeseed

c) Paddy

d) Jatropha

Answer: c

Explanation: Soya bean, rapeseed, and Jatropha seeds are all the sources from which biofuel can be extracted. Whereas Paddy can’t be used as bio-fuel.

11. What is the specific gravity value of gasoline?

a) 0.3 to 0.6

b) 1 to 15

c) 0.7 to 0.78

d) 0.9 to 1.5

Answer: c

Explanation: The specific gravity value of gasoline is 0.7 to 0.78, the specific heat value of gasoline is 2.1 KJ/Kg o C and the calorific value of Diesel is 50 MJ/Kg.

12. What is the specific heat valueof gasoline?

a) 2.1 KJ/g o C

b) 4.1 KJ/Kg o C

c) 2.1 KJ/Kg o C

d) 4.1 KJ/g o C

Answer: c

Explanation: The specific heat value of gasoline is 2.1 KJ/Kg o C and the calorific value of Diesel is 50 MJ/Kg. Specific heat capacity is the amount of heat energy required to raise the temperature of a substance per unit of mass.

13. What is the calorific value of Diesel?

a) 40 MJ/Kg

b) 10 MJ/Kg

c) 50 MJ/Kg

d) 30 MJ/Kg

Answer: c

Explanation: The specific heat value of gasoline is 2.1 KJ/Kg o C and the calorific value of Diesel is 50 MJ/Kg. Calorific value is the measure of heat contained in the fuel by measuring the heat produced by the complete combustion of a specified quantity of it.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “ Alternative Fuels”.

1. Which are the two main alcohols used in the engine as a fuel?

a) Butanol and methanol

b) Propanol and butanol

c) Ethanol and propanol

d) Methanol and Ethanol

Answer: d

Explanation: Alcohols have been used as engine fuels for a long time, methanol and ethanol are the two main alcohols used in the engine as a fuel.

2. Which alcohol is used in racing car engine due to its high anti-knock rating?

a) Methanol

b) Ethanol

c) Propanol

d) Butanol

Answer: a

Explanation: Alcohols have a high anti-knock rating, due to which, especially methanol, have been used in racing car engines. Flame of methanol fire is difficult to be seen in daylight, due to which it may not be detected.

3. Flame of which alcohol is difficult to be seen in daylight?

a) Methanol

b) Ethanol

c) Propanol

d) Butanol

Answer: a

Explanation:Flame of methanol fire is difficult to be seen in daylight, like LPG, petrol or other fuels its flame doesn’t produce any color, due to which it may not be detected.

4. Due to which alcohol corrosion of rubber and aluminum parts occur?

a) Methanol

b) Ethanol

c) Propanol

d) Butanol

Answer: b

Explanation: Corrosion of rubber, magnesium, and aluminum parts occurs at higher ethanol percentages, and also it is electrically conducting, this can cause a problem with some electric fuel pumps.

5. Which alcohol is electrically conducting and used as fuel?

a) Methanol

b) Ethanol

c) Propanol

d) Butanol

Answer: b

Explanation: Ethanol is electrically conducting, many sensors and electrical devices are connected to the engine. This can cause a problem with some electric fuel pumps.

6. What is the reason for ethanol to be difficult to ignite at a lower temperature?

a) High combustion

b) Aroma

c) structure of hydrocarbon

d) Less volatile

Answer: d

Explanation: Pure ethanol is less volatile than petrol due to which it becomes difficult to ignite at lower temperatures, which means, starting a cold engine during winter is difficult.

7. Which Ethanol is not used in light-duty vehicles?

a) E95

b) E15

c) E10

d) E85

Answer: a

Explanation: E10, E15, and E85 are used for light-duty vehicles and E95 is used in Heavy-duty vehicles e.g., trucks and buses. Hence, E95 is the right answer.

8. The Natural Gas consists of 95% of which gas?

a) Methane

b) Butane

c) Propane

d) Ethane

Answer: a

Explanation: The natural gas, like petroleum, comes from underground reserves. It consists, mainly of 95% of methane and the remaining 5% comprises butane, propane, and ethane with a small amount of water vapor.

9. Compared to petrol, CNG combustion produces 25% less of what gas?

a) NOx

b) H

c) CO

d) CO 2

Answer: d

Explanation: Compared to petrol, compressed natural gas produces about 25% less CO 2 and due to high levels of methane, it gives the highest HC emission.

10. LNG consist of more than 98% of which gas?

a) Propane

b) Ethane

c) Methane

d) Butane

Answer: c

Explanation: During the liquefaction process, natural gas is cooled below its boiling point removing most of the water vapor, butane, propane, etc., so that LNG is more than 98% methane.

11. The LPG is a by-product of the fractional distillation of which fuel?

a) Coal

b) Kerosene

c) Diesel

d) Petrol

Answer: d

Explanation: The liquefied petroleum gas is a by-product of the fractional distillation of petrol, consisting mainly of Butane and propane, used as engine fuel.

12. Which are two Hydrocarbons present in LPG?

a) Butane and Pentane

b) Methane and ethane

c) Butane and propane

d) Pentane and Hexane

Answer: c

Explanation: The liquefied petroleum gas is a by-product of the fractional distillation of petrol, consisting mainly of Butane and propane, used as engine fuel.

13. Bio-diesel is made of what residuals?

a) Plant oil

b) Animal fat

c) Plant oil and animal fat

d) Edible oil

Answer: c

Explanation: Bio-diesel is an alternative to standard diesel fuel, and is made from biological sources instead of petroleum, it is made from plant oils or animal fat.

This set of Automotive Engine Auxiliary Systems Question Bank focuses on “Intake System – Manifolds”.

1. What does inlet manifold carry to the engine?

a) Air

b) Fuel

c) Oxygen+ fuel

d) Air+ fuel

Answer: d

Explanation: Manifolds are the separate sets of pipes attached to the cylinder head. Inlet manifold carry the air-fuel mixture and exhaust manifold carry the exhaust gases.

2. Manifolds are connected to which part of the engine?

a) Cylinder

b) Cylinder head

c) Gasket

d) Engine block

Answer: b

Explanation: Manifolds are connected to the cylinder head of the engine. Manifolds have flanges at the end and it is bolted to the engine with the gasket in between.

3. In the petrol engine, the inlet manifold carries the air-fuel mixture from which part to the cylinder?

a) Air filter

b) Fuel injector

c) Fuel pump

d) Carburetor

Answer: d

Explanation: The inlet manifold carries the air-fuel mixture from the carburetor to the cylinders and the manifold must be larger enough to allow sufficient flow for maximum power.

4. The manifold must be larger enough to allow sufficient flow for what?

a) Max power

b) Max emission

c) Min emission

d) Lower torque

Answer: a

Explanation: The inlet manifold carries the air-fuel mixture from the carburetor to the cylinders and the manifold Inner surface must be very smooth such that it should not hold any charge around its surface.

5. Rough interior surfaces of the manifold runners will increase what to the mixture flow?

a) liquidity

b) Velocity

c) Smoothness

d) Resistance

Answer: d

Explanation: Rough interior surfaces of the manifold runners will increase resistance to the mixture flow and the surface of the exhaust manifold is made smooth to minimize the restriction of exhaust gas.

6. What is the another name of Manifold passages?

a) Riser

b) Sprout

c) Guideways

d) Runner

Answer: d

Explanation: Manifold passages are also called a runner. In modern automotive engines, the length of the intake track can be varied by both VLIM and VRIS technology, VLIM stands for Variable Length Intake Manifold, VRIS stands for Variable Resonance Induction System.

7. In modern automotive engines, the length of the intake track can be varied by which technology?

a) VLIM

b) VRIS

c) VIPS

d) Both VLIM and VRIS

Answer: d

Explanation: In modern automotive engines, the length of the intake track can be varied by both VLIM and VRIS technology, VLIM stands for Variable Length Intake Manifold.

8. Exhaust manifold is connected to which part of the engine?

a) Cylinder head

b) Engine block

c) Gasket

d) Muffler

Answer: a

Explanation: Exhaust manifold is connected to the Cylinder head of the engine; exhaust manifolds are usually made to give high efficiency and absorb the noise of high-pressure gas.

9. Exhaust manifolds are usually made of what material?

a) Copper

b) Chromoly

c) Mild steel

d) Cast iron

Answer: d

Explanation: Exhaust manifold is connected to the Cylinder head of the engine, exhaust manifolds are usually made of cast iron material and the exhaust manifold is designed to withstand heat.

10. The exhaust manifold is designed to withstand what?

a) Temperature

b) Gas

c) Heat

d) Contraction

Answer: c

Explanation: Exhaust manifold is connected to the Cylinder head of the engine, exhaust manifolds are usually made of cast iron material and the exhaust manifold is designed to withstand heat. Exhaust manifold has to result in better scavenging.

11. The surface of the exhaust manifold is made smooth to minimize the restriction of what?

a) Exhaust gas

b) Temperature

c) Heat

d) Contraction

Answer: a

Explanation: Rough interior surfaces of the manifold runners will increase resistance to the mixture flow and the surface of the exhaust manifold is made smooth to minimize the restriction of exhaust gas.

12. Modern engines have which valve to direct exhaust gas?

a) Heat risers

b) Thermal valve

c) Thermostatic heat riser

d) Static valve

Answer: c

Explanation: Modern engines have a thermostatic heat riser valve to direct exhaust gas and flange is the part of the manifold that is connected to the Cylinder head.

Answer: a

Explanation: Flanges are the type of coupling that is usually used to connect the propeller shafts. Flange is the part of the manifold that is connected to the Cylinder head.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Leakage Preventers – Gaskets”.

1. Which component is used to provide a tight-fitting joint between Cylinder and cylinder head?

a) Revet

b) Casting

c) Welding

d) Gasket

Answer: d

Explanation: Gaskets are used to provide a tight-fitting joint between Cylinder and cylinder head, between crank-case and oil pan, between the cylinder block and manifolds.

2. Which of the mentioned below is not the material of gasket?

a) Cork

b) PVC

c) Asbestos

d) Rubber

Answer: b

Explanation: Cork, Asbestos, and Rubber all the material used for different engine gasket, whereas PVC i.e., Poly-Vinyl Chloride is a material used in water pipes.

3. Cork is made of which natural resource?

a) Seeds

b) Animal fat

c) Fossils

d) Bark of Oak

Answer: d

Explanation: Cork is one of the oldest gasket materials obtained from the bark of oak and pine trees and oil-resistant synthetic rubber gaskets are frequently used in oil pan corner joints.

4. Which gaskets are frequently used in oil pan corner joints?

a) Oil-resistant synthetic rubber gasket

b) Fibers of asbestos

c) Cork

d) Heated cork

Answer: a

Explanation: Oil-resistant synthetic rubber gaskets are frequently used in oil pan corner joints. The material of these gaskets should be resistant to the chemical reactions.

5. What is the combustion pressure experienced by the gasket between the cylinder head and engine block in a petrol engine?

a) 1500KPa

b) 450KPa

c) 2000KPa

d) 700KPa

Answer: d

Explanation: The combustion pressure experienced by the gasket between cylinder head and engine block in a petrol engine is 700KPa and for turbo-charged diesel engine it is 2000KPa.

6. What is the combustion pressure experienced by the gasket between cylinder head and engine block in a turbocharged diesel engine?

a) 1500KPa

b) 450KPa

c) 2000KPa

d) 700KPa

Answer: c

Explanation: The combustion pressure experienced by the gasket between cylinder head and engine block for turbo-charged diesel engine it is 2000KPa. Since then the air is force injected, high pressure and temperature is generated.

7. What is the combustion temperature experienced by the gasket between the cylinder head and engine block in a petrol engine?

a) more than 1100°C

b) less than 700°C

c) more than 2400°C

d) less than 200°C

Answer: a

Explanation: The combustion pressure experienced by the gasket between cylinder head and engine block in a petrol engine is 700KPa and it should withstand the temperature more than 1100°C.

8. Which type of gasket is used on I-head engines?

a) Metal sandwich-type

b) Shim type

c) Embossed steel

d) Both Shim or embossed steel type

Answer: d

Explanation: Embossed steel or shim type is generally used on the I-head engine, metal sandwich type is made of either copper and asbestos or steel and asbestos; mainly used on passenger cars, trucks, etc.

9. Which type of gasket is used in passenger cars?

a) Shim type

b) Embossed steel

c) Shimbestos

d) Metal sandwich

Answer: d

Explanation: Metal sandwich type is made of either copper and asbestos or steel and asbestos; mainly used on passenger cars, trucks, etc. There is a chance of leakage of charge, so two metal sheets are integrated on either side of the gasket.

10. Which type of gasket is the combination of a thin steel heat shield and a specially treated metal-reinforced asbestos?

a) Shim type

b) Embossed steel

c) Shimbestos

d) Metal sandwich

Answer: c

Explanation: Shimbestos type of gaskets is the combination of a thin steel heat shield on one side and highly resilient, a specially treated metal-reinforced asbestos on the top of the side.

11. Which type of gasket is made of perforated steel sandwiched between two treated asbestos sheets?

a) Shim type

b) Embossed steel

c) Shimbestos

d) Felbestos

Answer: d

Explanation: Felbestos type of gasket is made of perforated steel sandwiched between two treated asbestos sheets and cork, Fecoid and Felcoprene are the material used as oil pan gasket.

12. Which material is not used as oil pan gaskets?

a) Cork

b) Felcoid

c) Asbestos

d) Felcoprene

Answer: c

Explanation: Cork, Fecoid, and Felcoprene are the material used as an oil pan gasket.The materials of these gaskets should be resistant to the chemical reactions and withstand high temperatures.

13. Which type of gaskets are treated to withstand anti-freezers?

a) Pump gasket

b) Manifold gasket

c) Oil pan gasket

d) Cylinder head gasket

Answer: a

Explanation: Several materials are available for pump gaskets such as asbestos, karropak, felcoid, etc, they are treated to withstand oil, water, petrol, and anti-freezers.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Engine Components – Cylinder Liners”.

1. Which among the following material is plated on the cylinder liner to improve the resistance to corrosion and wear?

a) Cast iron

b) Chromium

c) Zinc

d) Lead

Answer: b

Explanation: The liners are exposed to ammonia vapor at about 500 degrees centigrade and then quenched. Chromium plating improves the resistance to wear and corrosion. The use of chromium with aluminum alloy results in increased thermal efficiency.

2. Which type of casting process is used to cast cylinder liners?

a) Centrifugal casting

b) Investment casting

c) Die casting

d) Sand casting

Answer: a

Explanation: Liners are used to restore to its original size a cylinder block which has been rebored beyond allowable limits. They are made in the form of barrels from a special alloy containing silicon, manganese,nickel, and chromium. Liners are cast centrifugally.

3. Which type of fit is used with the block in a wet liner?

a) Slip fit

b) Press-fit

c) Friction fit

d) Hydraulic dilation

Answer: a

Explanation: In a wet liner the block and the liner are fitted together with the help of slip fit. It is the condition where the liner is meant to easily slip into the mating part with minimal friction. Whereas in the dry liner press fit is used to fit the liner and the cylinder block.

4. Which of the following is placed in between the liner and the water jacket in a dry liner?

a) Gasket

b) Cylinder block

c) Manifold

d) Piston

Answer: b

Explanation: The dry liner is made in the shape of a barrel flange at the top which keeps it into position. The entire outer surface bears against the cylinder block casting. The cylinder block prevents the contact of the water and liner there the attack of corrosion is less in dry liners.

5. Which among the following material is most commonly used in the manufacturing of cylinder liner?

a) Titanium

b) Copper

c) Brass

d) Grey cast iron

Answer: d

Explanation: The cylinder liners are made up of grey cast iron. In some cases, grey cast iron alloyed with chromium, vanadium, and molybdenum is used. The liners are manufactured either by centrifugal casting process or by gravity die casting process in metal or sand mold.

6. Which of the following is not the reason for the breaking of the flange in a wet liner?

a) Worn out counterbore seat

b) Excessive tightening of head bolts

c) Uneven counterbore

d) Damaged piston pin boss

Answer: d

Explanation: The breaking of a flange in a wet liner is due to the wrong tightening sequence of cylinder head bolts or their excessive tightening, uneven counterbore in the block to receive the liner, worn-out counterbore seats and not damaged piston pin boss.

7. Which of the following is coated outside along with a conventional cast-iron sleeve in a hybrid liner?

a) Austenitic steel 21-4N

b) Nimonic alloy

c) S.A.E 1045

d) AlSI 12 alloy

Answer: d

Explanation: The hybrid liner produced at Federal-Mogul’s Fried Berg  factory, consists of a conventional cast-iron sleeve coated on the outside with on AlSi 12 alloy with a melting point below that of the aluminum engine block, using a proprietary Federal-Mogul process.

8. What is the maximum pressure value in the bar of a hybrid liner?

a) 50

b) 150

c) 200

d) 100

Answer: c

Explanation: The hybrid liner has increased dynamic strength. Federal-Mogul’s cyclic pulsing pressure test showed the hybrid liner can survive at pressure up to 200bar, whereas standard liner block design cracked at 100 bar.

9. What is the percentage of heat transfer rate in a hybrid liner?

a) 50%

b) 90%

c) 30%

d) 70%

Answer: c

Explanation: The use of hybrid liners results in upto 30% higher heat transfer rates, which can reduce cylinder wall temperature by upto 40 degrees centigrade. The distortion of loads is claimed to be upto three times better, which results in upto 40% reduction in oil consumption.

10. What is the percentage of maximum second-order bore distortion in a conventional cast-in liners?

a) 11

b) 7

c) 5

d) 3

Answer: a

Explanation: The maximum second-order bore distortion in conventional cast-in liners is seen about 11% when compared to a hybrid liner the bore distortion is reduced in a running engine by two-thirds.

11.Which of the following technique is used to limit the crank formation in a hybrid liner?

a) Presence of a water channel

b) Presence of excess material

c) Presence of pressure relief valve

d) Presence of vent holes

Answer: a

Explanation: In a hybrid liner a water channel is drilled between two cylinders which limits the crack formation, allowing coolant to penetrate only upto the liner coating. In conventional liners, coolant may seep down the joint between the liner and the casting.

12. Which of the following results in a decrease in the scuffing near the sealing ring area?

a) Torque

b) Enthalpy

c) Engine speed

d) Running clearance

Answer: d

Explanation: Scuffing near the sealing ring area leads to localized hardening of the ring, very high pressure is exerted against the cylinder liner resulting in its distortion so that running clearance is deceased and the scuffing occurs near the affected area.

13. What is the wall thickness in millimeter preferred between cylinder bores in a hybrid liner?

a) 4

b) 5

c) 3

d) 2

Answer: c

Explanation: In a hybrid liner it is claimed that a 3mm wall thickness between cylinder bores is sufficient on pressure-die cast blocks, which me and reduced space between adjacent cylinders and hence improvement in overall engine packaging by OEMs.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Engine Components – Pistons”.

1. Which are the two materials used in a bimetallic piston?

a) Copper and steel

b) Magnesium and aluminum

c) Steel and cast iron

d) Aluminum and steel

Answer: d

Explanation: The bi-metal piston is made from both steel and aluminum. The skirt is formed by steel and the aluminum alloy cast inside of forms piston head and piston pin bosses. As the coefficient of thermal expansion for steel is quite small, the piston will not expand and hence smaller cold clearance can be maintained.

2. Which among the following is provided on the pistol in a two-stroke engine to increase the compression ratio?

a) Flat spot

b) Deflector

c) Damper

d) Nozzle

Answer: b

Explanation: In a two-stroke engine a deflector is provided on the piston to increase the compression ratio and even in the scavenging process by scavenging out the exhaust gases through the outlet port with the help of the fresh charge transferred via the transfer port.

3. Which among the following is the correct formula of the compression ratio in terms of clearance volume and swept volume?

a) R= swept volume+clearance volume

b) R=swept volume-clearance volume

c) R=2×

d) R=/clearance volume

Answer: d

Explanation: The compression ratio indicates the extent to which the charge in the engine is compressed. This is calculated as the ratio of the volume above the piston at B.D.C to the volume above the piston at T.D.C.R=/clearance volume.

4. By adding which of the following material to aluminum alloy piston slap can be avoided?

a) Silicon

b) Zinc

c) Copper

d) Lead

Answer: a

Explanation: The material added to the piston to avoid piston slap is silicon. The other advantage of adding silicon is the piston becomes harder and thus less liable to scuffing and wear. However, higher silicon content can also make the alloy brittle which leads to piston developing cracks if the detonation or pre-ignition occurs.

5. Which among the following casting process is used in the casting of the piston?

a) Investment casting

b) Low-pressure casting

c) Sand casting

d) Gravity die casting

Answer: d

Explanation: Pistons are either cast or forged. Castings are made by gravity die-cast process using 5-piece inner dies, a two-piece outer and usually ahead chill which can form anycast valve pockets and bowls. Core pins are used to form pinholes.

6. Which of the following is not a method to avoid piston slap?

a) Taper piston

b) Piston with T-slots

c) Offset piston

d) Increase the size of the piston skirt

Answer: d

Explanation: The methods of reducing piston slap are the use of a vertical or T-slots, taper piston, cam ground piston, use of special alloys, wire wound pistons, autothermic piston, bimetallic piston and offset piston whereas an increase in the piston skirt does not affect.

7. Which is the material used to wound on a wire wound piston?

a) Steel

b) Lead

c) Zinc

d) Magnesium

Answer: a

Explanation: In a wire wound piston a band of steel wire under initial tension is put between the piston pin and the oil control ring, thus restricting the expansion of the skirt which is of slip type or cam ground type. The main reason to wire-wound is to avoid piston slap.

8. Which among the following type is named when the silicon content is 12% in an aluminum alloy?

a) Eutectic

b) Hyper-eutectic

c) Hypo-eutectic

d) Pearlite

Answer: a

Explanation: Aluminum alloy containing silicon when increased leads to a decrease in its coefficient of expansion. Presently two alloy with silicon content 12% and 22%  are being used, which have less coefficient of expansion to that of aluminum.

9. Which of the following is the main reason for a burnt piston?

a) Hot air intake

b) Leak of coolant

c) More clearance

d) Detonation

Answer: d

Explanation: Burnt piston is chiefly on account of detonation or preignition. The burning due to detonation is generally at a point farthest from the spark plug where the hot end gases rapidly release their energy.

10. Which of the following part of the piston is shown in the arrow below?

a) Crown

b) Skirt

c) Piston rings

d) Piston pin boss

Answer: c

Explanation: The arrow mark shows the piston rings which are attached to the piston. There are generally two types of piston rings compression ring and oil control rings generally there is more compression rings on a piston when compared to oil rings.

11. Which of the following is not a reason for piston failure?

a) Insufficient lubrication

b) Overloading the engine

c) Detonation

d) Spark plug misfire

Answer: d

Explanation: Piston scuffing occurs due to excessive heat the piston expands and becomes tight in the cylinder. The main reasons for this are insufficient lubrication of cylinder walls, overloading the engine, detonation. Whereas spark plug misfire does not affect.

12. Which if the following is defined as the distance between the axis of the piston pin and top of the piston crown?

a) Clearance volume

b) Swept volume

c) Compression height

d) Detonation length

Answer: c

Explanation: The distance between the axis of the piston pin and the top of the piston crown is called compression height and determines the compression ratio for a given engine. Thus for the same engine, a piston with lesser compression height would give a lesser compression ratio and vice versa.

13. Which material is coated on the piston to increase the service life?

a) Tin

b) Zinc

c) Lead

d) Cadmium

Answer: a

Explanation: Piston is generally coated with tin plating to reduce the possibility of scoring. This even helps the piston in increased the service life of the engine piston. Tin plated surface treatment is antioxidant and tarnish resistant.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Engine Components – Crankshafts”.

1. To withstand which of the following the crank webs are made adequately strong?

a) To withstand the twisting and bending loads

b) To withstand the pressure difference

c) To withstand against the corrosion action

d) To withstand against the misfiring

Answer: a

Explanation: The crankwebs should be adequately strong to withstand the twisting and the bending loads. However increasing their size excessively would increase the inertia which would tend to wind and unwind the crankshaft when the engine is running.

2. Which of the following is defined as the distance between the axis of the main journal and the crankpin center lines is exactly one half of the engine stroke?

a) Crank length

b) Crank web

c) Crank-throw

d) Crank shift

Answer: b

Explanation: The distance between the axis of the main journal and the crankpin center lines is exactly one half of the engine stroke and is called crank-throw which determines the crankshaft turning effort.

3. Which of the following helps in the uniform speed of crankshaft despite uneven power impulses of the engine cylinder?

a) Piston

b) Connecting rod

c) Gasket

d) Flywheel

Answer: d

Explanation: The flywheel absorbs excess energy during the power stroke and gives out the absorbed energy during the other three strokes. Thus it is the flywheel that keeps the crankshaft rotating at the uniform speed throughout despite uneven power impulses of engine cylinders.

4. How much percentage of the cylinder bore size concerningthe thickness of the crank web?

a) 80

b) 60

c) 20

d) 40

Answer: c

Explanation: The design features of a crankshaft is that the crankpin length is at least 30% of its diameter,which itself usually not less than 60% of the cylinder core. The thickness of the crank web is usually about 20% of the cylinder bore size.

5. Which of the following is termed as the escape of the gasses from the combustion chamber and entering into the crankshaft?

a) Scuffing

b) Piston slap

c) Buckling

d) Blow-by

Answer: d

Explanation: Blow bye is the condition wherein the exhaust gasses escape from the combustion chamber and enter into the crankshaft and contamination of the oil takes place. To avoid this crankcase ventilation is provided.

6. In the below-shown diagram what is the make of the missing part of the counterweights?

a) Crankpin

b) Oil hole

c) Thrust bearing

d) Flywheel

Answer: a

Explanation: There are two types of counterweights and they are the integral counterweight and attached separately. The parts of both remain the same the parts are crankpin, Frank web and main journal, and counterweight. The above part is the crank pin.

7. Which of the following acts as a damper in a belt-driven crankshaft?

a) Fulcrum

b) Rocker arm

c) Belt

d) Strainer

Answer: c

Explanation: The vibration damper reduces the torsional vibration utilizing the dragging effect produced by the inertia of damper flywheel. Engines with belt-driven crankshaft do not need vibration damper. The belt acts as a damper.

8. Which of the following material is the most commonly used in the construction of crankshaft?

a) Cast steel

b) Bronze

c) Copper

d) lead

Answer: a

Explanation: The crankshaft was initially forged but later on casting of the crankshaft has also become quite common. The cast crankshaft both steel as well as S.G iron have been used. The S.G iron has a high strength cast iron in which carbon is in the form of spherical modules of graphite.

9. Which of the following is not a major part of the crankshaft?

a) Main journal

b) Crank pins

c) Water pump

d) Crank webs

Answer: c

Explanation: The main components of a crankshaft are the main journal, crankpins, crank webs, counterweights, and oil holes. Whereas the water pump has no role in the crankshaft construction. The main journal is supported in the main bearing in the crankcase.

10. How many types of crankshaft construction are used universally?

a) 1

b) 2

c) 4

d) 6

Answer: b

Explanation: The crankshaft are generally of two types, they are one piece and built up. In the built-up construction the crankpins and journals are bolted to crank arms, which also serves as flywheels. One-piece construction is almost universally used for automotive crankshaft.

11. How much is the ultimate tensile strength of the crankshaft material in MPa?

a) 400

b) 500

c) 600

d) 700

Answer: c

Explanation: The ultimate tensile strength of the crankshaft material is about 600 MPa. The crankshaft must be adequately strong, tough, hard, and should possess high fatigue strength. As such proper material has to be selected for the construction.

12. What is the percentage of carbon present in a cast steel type crankshaft?

a) 0-1

b) 2-4

c) 1.35-1.6

d) 4-6

Answer: c

Explanation: A typical cast steel for crankshaft has a carbon composition of 1.35-1.6 percentage. Along with carbon the stew contains chromium in 0.05-0.5 percentage, silicon 0.85-11 percentage, manganese 0.6-0.8 percentage etc.

13. Which of the following is also known as harmonic balancer?

a) Counterweight

b) Crank web

c) Vibration dampers

d) Main journal

Answer: c

Explanation: Vibration damper is also called a harmonic balancer. It is mounted on the front end of the crankshaft. It consists of a damper flywheel-cum- crankshaft pulley and a driving flange connected with a rubber ring in between.

This set of Automotive Engine Design Questions and Answers for Entrance exams focuses on “Valve Timing Technologies – Engine Bearings”.

1. What is the thickness in mm of the overlay which is provided on the bearings?

a) 0.01-0.02

b) 0.03-0.04

c) 0.05-0.06

d) 0.07-0.08

Answer: a

Explanation: The thickness of the overlay or the third layer of Babbit is used on top of the copper-lead and aluminum bearings. Due to overlay, which is 0.01-0.02 mm thick, such bearings are expensive.

2. How is one of the bearings made to prevent the crankshaft from moving to and fro in the endwise direction?

a) Magnetic bearing

b) Fluid bearing

c) Ball-bearing

d) Thrust bearing

Answer: d

Explanation: To prevent the crankshaft from moving to and fro in the endwise direction, one of the bearings is made a thrust bearing. It is provided with flanges on both sides, which fit accurately with the sides of the crank web on which it is installed.

3. Which of the following is provided to cushion the journal and to increase the life of the bearing?

a) Direction control valve

b) Overlay

c) Position control valve

d) Compressor

Answer: b

Explanation: A overlay or third layer of Babbit is used on top of the copper-lead and aluminum bearings. Due to the overlay, which is 0.01-0.02 mm thick, such bearings are expensive. However the overlay cushions the journal during the running-in period and thus increases the life of bearing as well as journal.

4. Which is the bearing material which is being used in the modern engine?

a) Brass

b) Cast iron

c) Aluminum

d) Chromium

Answer: c

Explanation: The bearing material used in modern engines is aluminum with small quantities of tin and copper, aluminum bearings are used for high load and speed conditions. However, it is more expensive due to which they are sometimes used with cheaper materials.

5. Which of the following helps the engine bearing by supporting the operating loads with minimum friction?

a) Good fuel-air ratio for combustion

b) Vibration dampers

c) Clutch

d) Lubricant

Answer: d

Explanation: The engine bearing has main requirements like the engine bearing should support the operating loads with minimum friction using lubricant. Whereas the fuel-air ratio, vibration-dampers, and clutch do not affect the engine bearings.

6. Which one of the following is not an engine bearing requirement?

a) Corrosion resistance

b) Long life

c) Should multiple the variation of the shafts

d) Should have score resistance

Answer: c

Explanation: The engine bearing requirements are: they should have a long life, the bearing should have score resistance that prevents the bearing material from seizing to the shaft, corrosion resistance. Whereas the bearing has to have the ability to flow slightly to match the small variations in the shaft and not to multiply the variations.

7. Which are the types of material used in Babbit type bearing material?

a) Lead with a small quantity of copper and antimony

b) Steal with a small quantity of zinc and tin

c) Zinc with a small quantity of lead and copper

d) Silver with a small quantity of brass and aluminum

Answer: a

Explanation: Babbit is made by either lead or tin-based and contains a small quantity of copper and antimony. It is the oldest bearing material for automobile engines and is still used in application where soft material shaft under the moderate loads and speeds is employed.

8. Which of the following material is usually used in the backing to provide support against the shaft load?

a) Lead

b) Copper

c) Tim

d) Steel

Answer: d

Explanation: A modern engine bearing consists of bearing proper and a backing. The.backing is usually of steel which provides support against the shaft load acting on the shaft. There are three types of bearing material they are Babbit,copper-lead, and aluminum.

9. Which of the following more when compared to others in a medium-duty sealed powder bearings?

a) Conformability

b) Embeddability

c) Corrosion

d) Fatigue strength

Answer: d

Explanation: In a medium-duty sealed powder bearing copper alloy lining with steel back. Copper-based alloys are harder and have higher fatigue strength but less conformability, embeddability, and corrosion resistance.

10. What is the value of antimony present in a Babbit metal?

a) 5.5

b) 7.5

c) 6.5

d) 8.5

Answer: b

Explanation: The Babbit metal are either antimony-tin or antimony-lead alloys. They have a very good conformability, embeddability, and corrosion resistance but a low fatigue strength. It has 7.5% of antimony, 0.2% lead, 0.1% arsenic, 3.0% copper and tin remainder.

11. Why are the holes provided in a main bearing as shown below?

a) To look attractive

b) For lubrication

c) Release the pressure

d) Vibration damping

Answer: b

Explanation: The oil holes are drilled from the main bearing to the crankpins through crank webs to provide lubrication of bug end bearing. Main bearings are lubricated from oil galleries in the cylinder block.

12. What is the value of silicon and copper in an extra heavy-duty type sealed power bearing?

a) 11% silicon and 1% copper

b) 1% silicon and 11% copper

c) 5% silicon and 10% copper

d) 10% silicon and 5% copper

Answer: a

Explanation: The extra heavy-duty sealed power bearing is made up of tin flash plate, Babbit over plate, aluminum alloy lobbying, and steel back. This contains 11% silicon, 1% copper, and the remainder aluminum. These alloys do not suffer corrosion as it is copper-based alloy.

13. Which of the following when decreased reduces the bearing clearance?

a) Number of shims

b) Number of valves

c) Displacement of the piston

d) Number of spark plugs

Answer: a

Explanation: Several shims are present on each side of the bearing, within it and the cap are also provided in the cast type for adjustment of clearance. Taking out several shims leads to a reduction in the bearing clearance.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Valve Timing”.

1. Theoretically, the inlet valve should open at what position of the piston?

a) Bottom dead centre

b) Side centre position

c) Bottom side position

d) Top dead centre

Answer: d

Explanation: Theoretically the inlet valve should open at Top dead position of the piston and the inlet valve should close at Bottom dead centre position of the piston.

2. Theoretically, the inlet valve should close at what position of the piston?

a) Bottom dead centre

b) Side centre position

c) Bottom side position

d) Top dead centre

Answer: a

Explanation: Theoretically the inlet valve should close at Bottom dead centre position of the piston.The exhaust valve opens before the piston reaches BDC in its power stroke.

3. Theoretically, the exhaust valve should open till the piston reaches which position?

a) Bottom dead centre

b) Side centre position

c) Bottom side position

d) Top dead centre

Answer: d

Explanation: Theoretically the inlet valve should open at the top dead center position of the piston and the exhaust valve should open till the piston reaches the top dead centre.

4. Due to which factor, the valves can’t open instantaneously?

a) Inertia

b) Torsional

c) Momentum

d) Point load

Answer: a

Explanation: In practice, due to inertia the valves cannot open instantaneously, and also the air-fuel mixture has its inertia. Consequently, more time has to be allowed for the intake and exhaust process to complete.

5. What is the event known as when the inlet valve is generally opened about 50° TDC is known as?

a) Valve bent

b) Valve break

c) Valve lag

d) Valve lead

Answer: d

Explanation: The inlet valve is generally opened about 50° TDC is known as valve lead and the inlet valve is generally closed after 45° of BDC is known as Valve lag.

6. What is the event known as when the inlet valve is generally closed after 45° of BDC?

a) Valve bent

b) Valve break

c) Valve lag

d) Valve lead

Answer: c

Explanation: The inlet valve is generally closed after 45° of BDC is known as Valve lag.This valve timing can increase or decrease the power of the engine. Hence, precision is required in valve timing.

7. Practically, the inlet valve opens between what range before TDC?

a) 10°-30°

b) 40°-75°

c) 20°-60°

d) 80°-150°

Answer: a

Explanation: Practically, the inlet valve opens between 10°-30° range before TDC, Exhaust valve opens at 40°-75° range before BDC, Valve overlap at 20°-60° range at TDC and Valve overlap at 80°-150°range at BDC.

8. Practically, Exhaust valve opens at what range before BDC?

a) 10°-30°

b) 40°-75°

c) 20°-60°

d) 80°-150°

Answer: b

Explanation: The exhaust valve opens before the piston reaches BDC in its power stroke. Practically, the inlet valve opens between 10°-30° range before TDC, Exhaust valve opens at 40°-75° range before BDC.

9. Practically, Valve overlap at what range at TDC?

a) 10°-30°

b) 40°-75°

c) 20°-60°

d) 80°-150°

Answer: c

Explanation: Practically, Valve overlap at 20°-60° range at TDC and Valve overlap at 80°-150° range at BDC. Valve overlap is the time during which both the inlet and exhaust valves remain open at the same time.

10. Practically, Valve overlap at what range at BDC?

a) 10°-30°

b) 40°-75°

c) 20°-60°

d) 80°-150°

Answer: d

Explanation: Practically, Valve overlap at 20°-60° range at TDC and Valve overlap at 80°-150° range at BDC. Theoretically, the valves open and close instantaneously at the dead centers.

11.The maximum valve opening depends directly on what factor?

a) Throttle position

b) Valve drop

c) Power output

d) Valve peak lift

Answer: d

Explanation: The maximum valve opening depends directly on valve peak lift and the maximum power output of the engine would generally be increased by increasing valve peak lift.

12. The maximum power output of the engine would generally be increased by increasing what?

a) Throttle position

b) Valve drop

c) Power output

d) Valve peak lift

Answer: d

Explanation: The maximum power output of the engine would generally be increased by increasing the valve peak lift. Higher the valve lift, the more the charge can enter the cylinder. Hence, more power is obtained.

13. Which of the mentioned below is not a type of valve?

a) Poppet valve

b) Sleeve valve

c) Rotary valve

d) Non-return valve

Answer: d

Explanation: The Poppet valve, sleeve valve, and rotary valve are all the types of valve used in an internal combustion engine, whereas the Non-return valve is used in the fuel pump.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Poppet Valves”.

1. Which of the mentioned below is the advantage of a poppet valve?

a) Moment of inertia

b) Shape

c) Lightweight

d) Self-centering

Answer: d

Explanation: Simplicity of construction, self-centering, free to rotate about the stem, maintenance of sealing efficiency are all the advantages of the poppet valve.

2. Generally which valve is larger?

a) Exhaust valve

b) Inlet valve

c) Exhaust port

d) Oil port

Answer: b

Explanation: Generally inlet valves are larger than the exhaust valves because the speed of incoming air-fuel mixture is less than the velocity of exhaust gases which leave under pressure.

3. What is the inlet valve face angle that is generally kept?

a) 25°

b) 30°

c) 45°

d) 45° or 30°

Answer: d

Explanation: The inlet valve face angle is generally kept 45° or 30°. A smaller angle provides greater valve opening for a given lift, but poor sealing because of the reduced sealing pressure for a given spring load.

4. What is the exhaust valve face angle that is generally kept?

a) 25°

b) 30°

c) 45°

d) 45° or 30°

Answer: c

Explanation: The exhaust valve face angle is only 45°, as this increases its heat dissipation. In some cases, a further differential angle of about ½ deg to 1 deg is provided between the valve and its seating.

5. Circumferential and longitudinal direction of valve experience which stress?

a) Shear stress

b) Principal stress

c) Longitudinal cyclic stress

d) Thermal stress

Answer: d

Explanation: Thermal stresses in the circumferential and longitudinal directions due to the large temperature gradient from the centre of the head to its periphery and from the crown to the stem.

6. Which property of the valve resists the tensile loads and stem wear?

a) Strength

b) Hardness

c) Both strength and hardness

d) Toughness

Answer: c

Explanation: Exhaust valve material requires high strength and hardness to resist tensile loads and stem wear. High hot strength and hardness to combat head cupping and wear of seats.

7. The least coefficient of thermal expansion to avoid excessive thermal stress is experienced by which part of the valve?

a) Head

b) Face

c) Stem

d) Margin

Answer: a

Explanation: The Least coefficient of thermal expansion to avoid excessive thermal stress is experienced by the head part of the valve because it experiences the heat from the combustion directly.

8. To avoid corrosion, the valve is given a coating with what material?

a) Copper

b) Chromium

c) Zinc

d) Aluminum

Answer: d

Explanation: To avoid corrosion, the valve is given an aluminum coating. Aluminum oxide formed separates the valve stem from the cast iron seat to keep the face metal sticking.

9. What is the highest temperature experienced by the exhaust valve?

a) 550 o C

b) 400 o C

c) 900 o C

d) 750 o C

Answer: d

Explanation: The exhaust valve temperature in modern engines reach very high valves of the order of 750 o C and sodium is present inside the hollow stem of the valve.

10. What is present inside the hollow stem of the valve?

a) Ethyl-glycol

b) Magnesium

c) Sodium

d) Mercury

Answer: c

Explanation: The exhaust valve temperature in modern engines reach very high. So, sodium is present inside the hollow stem of the valve. These valves are also used in Heavy engines.

11. Which material is generally used in valve springs?

a) Carbon steel

b) Chromium-vanadium steel

c) Nickel-chromium steel

d) Both carbon steel or chromium-vanadium steel

Answer: d

Explanation: The valve springs are made from high-grade spring steel wire, the materials being generally hard-drawn carbon steel or chromium-vanadium steel.

12. What is present around the valve in the engine for the cooling?

a) Radiator

b) Ice pack

c) Water jacket

d) Fan

Answer: c

Explanation: Water jackets are present around the valve in the engine for the cooling and there is a small clearance around the stem of the valve for lubrication.

13. Why there is a small clearance around the stem of the valve?

a) Lubrication

b) Cooling

c) Heating

d) Strengthening

Answer: a

Explanation: The small clearance around the stem of the valve for lubrication. The valves experience a high temperature since it is in direct contact with the combustion heat. Hence, lubrication is required.

This set of Automotive Engine Auxiliary Systems Questions and Answers for Campus interviews focuses on “Valve Train Component Details”.

1. What is that part of a cam lobe which controls the valve opening called as?

a) Coldspot

b) Hot spot

c) Low spot

d) High spot

Answer: d

Explanation: A camshaft is a shaft with a cam for each intake and exhaust valve. Each cam has a high spot called cam lobe which controls the valve opening.

2. In which type of engine Valve train is not present?

a) 4-stroke petrol engine

b) 2-stroke petrol engine

c) 4-stroke diesel engine

d) Boxer engine

Answer: b

Explanation: Valve train is not present in the 2-stroke petrol engine, but to do the same work valves are replaced by ports, and its opening and closing is done by piston itself.

3. How many cam lobes are present on the camshaft per cylinder?

a) 6

b) 5

c) 3

d) 2

Answer: d

Explanation: There will be two cam lobes per cylinder head, one is for intake valve and another is for exhaust valve. In modern engines, Dual overhead cams are also present.

4. Why is the clearance given between bearing journals and the bores?

a) lubrication and metal expansion

b) Friction

c) For lubrication

d) Thermal expansion

Answer: a

Explanation: The clearance given between bearing journals and the bores are given for lubrication and metal expansion in the range of 0.05 to 0.125mm.

5. What is the range of clearance given between bearing journals and the bores?

a) 0.06 to 0.5cm

b) 0.025 to 1.2mm

c) 0.5 to 1cm

d) 0.05 to 0.125mm

Answer: d

Explanation:The clearance given between bearing journals and the bores are given in the range of 0.05 to 0.125mm. This also helps in cooling and reduces the wear due to friction.

6. The end wise movement of the camshaft is limited by which component?

a) Key

b) Spigot

c) Thrust plate

d) Shear plate

Answer: c

Explanation:The end wise movement of the camshaft is limited by the thrust plate. Shear plate is added to bear the load in the weak joint of the welding.

7. What is the speed of the camshaft rotation?

a) Half the crankshaft speed

b) Double the crankshaft speed

c) Thrice the crankshaft speed

d) Same as crankshaft speed

Answer: a

Explanation: The speed of the camshaft rotation is half the crankshaft speed and in overhead cams,Chain or belt type of drive is used to drive the camshaft.

8. In overhead cams, which type of drive is used to drive camshaft?

a) Gear

b) Chain or belt

c) Chain

d) Toothed belt

Answer: b

Explanation: Chain or belt type of drive is used to drive the camshaft. Gears are space consuming and adds weight to the engine and also is requires lubrication. So, gears are not used.

9. Which component, transmit the torque load from the drive to the drive pulley?

a) Facing

b) Backing plate

c) Molded teeth

d) Load-carrying cords

Answer: d

Explanation: Load-carrying cords are used to transmit the torque load from the drive to the drive pulley. These are made of very strong flexible glass-fiber cords.

10. What are bonded to the inside layer of the load-carrying cords?

a) Facing

b) Backing plate

c) Molded teeth

d) Load-carrying cords

Answer: c

Explanation: Moulded teeth, which provide grip. Neoprene rubber teeth moldings are bonded to the inside layer of the load-carrying cords. Silent drive is the advantage of the toothed belt drive.

11. Which of the mentioned is the advantage of the toothed belt drive?

a) Silent drive

b) High vibration

c) High heat built up

d) High lubrication

Answer: a

Explanation: In a flat belt type, the stress distribution is uneven and there is a slip. To overcome this V-tooths are made on it. Silent drive is the advantage of the toothed belt drive.

12. Which material is not used for timing gear?

a) Cast iron

b) Steel

c) Nichrome

d) Aluminum

Answer: c

Explanation: Cast iron, steel, and aluminum are all the material used in timing gear based on their life. Whereas nichrome is a material that is usually found on the heating element.

Answer: a

Explanation: Increased volumetric efficiency and reduced pumping losses can be done by varying cam timing using a Variable cam phaser component.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Variable Valve Timing”.

1. Which technology changes the timing of intake/exhaust valves when the engine is running?

a) CRDI

b) DOHC

c) TDI

d) VVT

Answer: d

Explanation: VVT is a generic term for an automobile engine technology that allows the timing os the intake/exhaust valves to be changed when the engine is working.

2. Which system can change independently the valve-event timing and valve lift?

a) Profile switching system

b) Phase changing system

c) Variable event-timing system

d) Variable lift system

Answer: a

Explanation: The profile switching system can change independently of the valve-event timing and valve lift. Variable event-timing system can change both the phase and duration of the valve event.

3. Which system can change both the phase and duration of the valve event?

a) Profile switching system

b) Phase changing system

c) Variable event-timing system

d) Variable lift system

Answer: d

Explanation: Variable event-timing system can change both the phase and duration of the valve events and can be optimized at different engine speeds and load conditions.

4. Which system reduces the pumping losses due to conventional throttle?

a) Profile switching system

b) Phase changing system

c) Variable event-timing system

d) Variable lift system

Answer: d

Explanation: Variable lift system has the main advantage of reducing the pumping losses due to conventional throttle. Variable event-timing system can change both the phase and duration of the valve events.

5. What does VTEC stands for?

a) Valve timing and lift electronic control system

b) Variable valve timing and lift electronic system

c) Variable timing electronic system

d) Variable valve timing and lift electronic control system

Answer: d

Explanation: VTEC stands for variable valve timing and lift electronic control system. This creates a large amount of overlap between the inlet and the exhaust valves, is beneficial at high speeds.

6. What results in the use of a high degree of overlap inat lower engine speed?

a) Loss of torque

b) Gain of performance

c) loss of torque and performance

d) Gain of torque and performance

Answer: c

Explanation: The use of a high degree of valve overlap results in a loss of torque and performance at lower engine speeds. Moreover, the engine idling is also unstable-the engine hunts and misses, on stall.

7. What is the value of the valve overlap, for a smooth idle and healthy low rpm torque?

a) 0

b) 40°-75°

c) 1

d) 80°-150°

Answer: a

Explanation: For a smooth idle and healthy low rpm torque we need to have zero valve overlap between the inlet and exhaust valve. Hence, 0 is the right answer.

8. Which type of valve system does the VTEC uses in Indian ‘Honda city’?

a) DOHC

b) SOHC

c) TDCI

d) CRDI

Answer: b

Explanation: The VTEC used in Indian ‘Honda city’ is a SOHC type that varies the timing and lift of only the intake valves. The DOHC type of VTEC varies valve timing and lift of both the intake and exhaust valves.

9. Which valve system varies the valve timing and lift of both intake and exhaust?

a) DOHC

b) SOHC

c) TDCI

d) CRDI

Answer: a

Explanation: The VTEC used in Indian ‘Honda city’ is a SOHC type that varies the timing and lift of only the intake valves. The DOHC type of VTEC varies valve timing and lift of both the intake and exhaust valves. – duplicate of Q8

10. What was the Fiat’s new air management technology in 2009 known as?

a) I-VTEC

b) VVTEC

c) Turbo engine

d) MultiAir

Answer: d

Explanation: Fiat unveiled its new air management technology named ‘MultiAir’ at the 2009 Geneva Motor Show. This is a real technological breakthrough and claimed to be much better than the VVT system.

11. How many valves per cylinder are used in Multi air technology?

a) 1

b) 2

c) 3

d) 4

Answer: d

Explanation: In this technology, instead of twin camshafts of four valves per cylinder engine, a single camshaft opens up all four valves and eliminates engine pumping losses.

12. By which component in a Camless engine, each engine valve is operated individually?

a) ECU

b) Cam

c) Sensor

d) Actuator

Answer: d

Explanation: In a Camless engine, each engine valve is operated individually by an actuator. There is no camshaft. So cylinder deactivation is possible.

13. Which of the mentioned bellow is a disadvantage of a poppet valve?

a) Cold start wear

b) Higher overall valve train efficiency

c) Cylinder deactivation

d) Valve stem scuffing

Answer: d

Explanation: Valve stem scuffing is due to geometrical irregularities or over-speeding. This can be corrected by bent or slanted valve, which may need replacement.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Exhaust System – Mufflers”.

1. What pressure does an exhaust gases have?

a) Medium level pressure

b) Low pressure

c) No pressure

d) High pressure

Answer: d

Explanation: When the exhaust valve opens, the high-pressure exhaust gas is released, which causes a pressure wave in the air causing an explosion.

2. What is the low-frequency note of an exhaust gas?

a) 50 to 500Hz

b) 5 to 10Hz

c) 3000 to 10000Hz

d) 30000 to 200000Hz

Answer: a

Explanation: The predominant notes out of these have been found in two groups, viz, low-frequency notes from 50 to 500Hz, and high-frequency notes from 3000 to 10000Hz.

3. What is the high-frequency note of an exhaust gas?

a) 50 to 500Hz

b) 5 to 10Hz

c) 3000 to 10000Hz

d) 30000 to 200000Hz

Answer: c

Explanation:Exhaust gases have a very high temperature and pressure, when this strikes the walls of the exhaust system, they produce a high-frequency notes from 3000 to 10000Hz.

4. Which part is connected to the engine exhaust via an exhaust pipe,to reduce the noise?

a) Silencer

b) Valve

c) Header

d) Manifold

Answer: a

Explanation:To reduce the noise, the engine exhaust is connected via an exhaust pipe to the silencer, which is also called muffler. Muffler reduces noise by canceling the waves.

5. To which part a tailpipe carries the exhaust gas to the rear side near wheels?

a) Valve

b) Header

c) Manifold

d) Muffler

Answer: d

Explanation: A tailpipe carries the exhaust gases from the muffler to the rear or side of the vehicle near the wheel. Muffler reduces noise by canceling the waves.

6. Which of the mentioned below is not a type of muffler?

a) Baffle type

b) Resonance type

c) Light type

d) Absorber type

Answer: c

Explanation: Baffle type, Wave cancellation type, Resonance type, Absorber type, and Combined resonance and absorber type are all the types of mufflers. Whereas light type is not a muffler.

7. Which is the major drawback of the baffle type of muffler?

a) Restriction of exhaust gas

b) Free flow of exhaust gas

c) Wave cancellation

d) Reduced noise

Answer: a

Explanation: The major drawback of the baffle muffler is their low efficiency. Because of the restriction provided to the flow by the baffles, the backpressure is increased thus causing a loss in engine power.

8. In which type of muffler crest of one wave coincide with the trough of the second wave?

a) Baffle type

b) Wave cancellation type

c) Resonance type

d) Absorber type

Answer: b

Explanation: In wave cancellation type, the length of these paths is so adjusted that after they come out of the muffler, the crest of one wave coincides with the trough of the second wave, thus reducing noise.

9. What is the other name of resonance type muffler?

a) Mizer type

b) Max type

c) Helmholtz type

d) Heisenberg type

Answer: c

Explanation: Resonance type muffler is also called a Helmholtz type, after the person who originated the idea. It consists of several Helmholtz resonators in series.

10. In which type of muffler series of resonators are connected?

a) Baffle type

b) Wave cancellation type

c) Resonance type

d) Absorber type

Answer: c

Explanation: Resonance type muffler is also called a Helmholtz type, after the person who originated the idea. It consists of several Helmholtz resonators in series. Series of resonators eliminate the fundamental and higher harmonics of the engine noise.

11. In which type of muffler fiberglass is used?

a) Baffle type

b) Wave cancellation type

c) Resonance type

d) Absorber type

Answer: d

Explanation: In absorber type muffler, the sound-absorbing material, usually fiberglass, is placed in this case around the perforated tube through which the exhaust gases pass.

12. Which type of mufflers are called as glass packed mufflers?

a) Baffle type

b) Wave cancellation type

c) Resonance type

d) Absorber type

Answer: d

Explanation: In absorber type muffler, the sound is reduced by conversion into heat by sound-absorbing material. Such mufflers are commonly known as glass packed mufflers.

13. Combined resonance and absorber type muffler has sound-absorbing material in it?

a) True

b) False

Answer: a

Explanation: Combined resonance and absorber type muffler is a combination of both resonance and absorber type. This contains fiberglass as a noise absorbing material.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Petrol Engine Fuel Supply System – Supercharging”.

1. What is the another name of supercharger?

a) Pump

b) Diffuser

c) Cooler

d) Compressor

Answer: d

Explanation: A Supercharger is an air compressor that increases the pressure of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen.

2. Which of the mentioned below is not a driving mechanism of a supercharger?

a) Exhaust gas

b) Belt

c) Gear

d) Chain

Answer: a

Explanation:Power for the supercharger can be provided mechanically using a belt, gear, shaft, or chain connected to the engine’s crankshaft.

3. For a super charger, the drive is obtained by which part of the engine?

a) Cam

b) Connecting rod

c) Exhaust manifold

d) Crankshaft

Answer: d

Explanation: Power for the supercharger can be provided mechanically using a belt, gear, shaft, or chain connected to the engine’s crankshaft. Whereas, turbocharger is driven by exhaust gas.

4. Which are the types of supercharger based on method of gas transfer?

a) Positive displacement and dynamic compressors

b) Positive displacement and negative displacement

c) Dynamic compressors and Static compressors

d) Negative displacement and Static compressors

Answer: a

Explanation: There are two main types of superchargers defined according to the method of gas transfer, they are positive displacement and dynamic compressors.

5. Which supercharger delivers an almost constant level pressure increase at all engine RPM?

a) Dynamic compressor

b) Negative displacement

c) Static compressor

d) Positive displacement

Answer: d

Explanation: Positive displacement supercharger deliver an almost constant level pressure increase at all engine RPM and Dynamic compressor does not deliver pressure at low speeds; above the threshold, speed pressure increases exponentially.

6. Which supercharger doesn’t deliver pressure at low speeds?

a) Dynamic compressor

b) Negative displacement

c) Static compressor

d) Positive displacement

Answer: a

Explanation: Positive displacement supercharger deliver an almost constant level pressure increase at all engine RPM; above the threshold, speed pressure increases exponentially in a compressor.

7. On what basis positive displacement superchargers are usually rated?

a) Capacity per revolution

b) Parts per million

c) Displacement of engine

d) Size of exhaust manifold

Answer: a

Explanation: Positive displacement superchargers are usually rated by their capacity per revolution. In this case of the roots blower, the GMC rating pattern is typical.

8. Which of the mentioned below is the disadvantage of supercharger?

a) More volume of air

b) Increase in temperature

c) Higher density

d) Cold air

Answer: b

Explanation: One disadvantage of supercharging is that compressing the air increases its temperature. Extreme temperature will cause detonation of the fuel-air mixture.

9. Internal compression devices usually use varying compression ratio.

a) True

b) False

Answer: b

Explanation: Internal compression devices usually use a fixed internal compression ratio. When the boosted pressure is equal to the compression pressure of the supercharger, the backflow is zero.

10. When the boosted pressure is equal to the compression pressure of the supercharger, what is the value of the backflow?

a) 10

b) 4

c) 2

d) 0

Answer: d

Explanation: When the boosted pressure is equal to the compression pressure of the supercharger, the backflow is zero. Since the backflow is zero, further the air is forcefully injected and higher power is obtained.

11. Which are the types of dynamic compressors?

a) Centrifugal and centripetal

b) Single-stage and multi-stage axial flow

c) Centripetal and single-stage axial flow

d) Centrifugal and multi-stage axial flow

Answer: d

Explanation: Dynamic compressors rely on accelerating the air to high speed. Major types of dynamic compressors are centrifugal and multi-stage axial flow.

12. What happens to the engine if there is an increase in the temperature of the air+fuel mixture?

a) Lower vibration

b) Higher torque

c) High efficiency

d) Detonation

Answer: d

Explanation: One of the disadvantages of supercharging is that compressing the air increases its temperature. Extreme temperature will cause detonation of the fuel-air mixture.

13. In two-stroke engines, what is required to purge exhaust gasses?

a) Lighter piston

b) Lubrication

c) Oil

d) Scavenging

Answer: d

Explanation: In two-stroke engines, scavenging is required to purge exhaust gasses, as well as charge the cylinders for the next power stroke. In small engines, this requirement is commonly met by using the crankcase as a blower.

This set of Automotive Engine Auxiliary Systems Problems focuses on “Petrol Engine Fuel Supply System – Superchargers Types”.

1. Which of the mentioned below is not a type of supercharger?

a) Centrifugal type

b) Root’s type

c) Screw type

d) Nut type

Answer: d

Explanation: Centrifugal type, root’s type, vane type, screw type are all the types of superchargers whereas nut type is not present as a supercharger.

2. Which type of supercharger has an impeller at the center?

a) Root’s type

b) Centrifugal type

c) Vane type

d) Screw type

Answer: b

Explanation: In centrifugal-type supercharger, the air/fuel mixture enters the impeller at the center and after passing through the impeller and the diffuser vane, it enters the volute casing.

3. Which material is used in impellers of Centrifugal supercharger?

a) Nichrome

b) Iron

c) Copper

d) Alloy steel

Answer: d

Explanation: The impeller runs at a very high speed, which should be able to take the accompanying stresses at such high speeds. Generally, impellers are made of duralumin, or alloy steels.

4. Which type of supercharger consists of two rotors of epicycloid shape?

a) Root’s type

b) Centrifugal type

c) Vane type

d) Screw type

Answer: a

Explanation: Root’s supercharger consists of two rotors of epicycloid shape. An epicycloid is the locus of a point on the circumference of a circle which rolls on another circle.

5. Which type of pump is Eaton 5 th generation supercharger?

a) Dynamic compressor

b) Negative displacement

c) Static compressor

d) Positive displacement

Answer: d

Explanation: Eaton 5 th generation supercharger is a root’s type positive displacement pump with no internal compression. Each of the tri-lobe rotors are twisted to 60 degrees to reduce noise.

6. In a vane-type supercharger, the drum slide in or out against which force?

a) Centrifugal force

b) Centripetal force

c) Inertia force

d) Spring force

Answer: d

Explanation: In a vane-type supercharger, several vanes are mounted on the drum in such a manner that they can slide in or out against some spring force.

7. Which of the mentioned below is not a desired property of vane material?

a) High strength

b) Low friction

c) Low coefficient of thermal expansion

d) Quiet running

Answer: a

Explanation: The properties required for a vane material are quiet running, low friction, low coefficient of thermal expansion, and resistance to continuous exposure to oil and petrol.

8. Which type of supercharger, compress the air between two intermeshing screws?

a) Screw type

b) Root type

c) Nut type

d) Vane type

Answer: a

Explanation: Screw type supercharger compresses the air between two intermeshing screws, in root’s supercharger consists of two rotors of epicycloid shape to compress the air.

9. In which type of supercharger, the compressing air travels along the screw axis?

a) Screw type

b) Root type

c) Nut type

d) Vane type

Answer: a

Explanation: Screw type supercharger compresses the air between two intermeshing screws, taking it at one end and compressing the air as it travels along the screw axis.

10. On which engines, the centrifugal-type supercharger has been mainly used?

a) Automobile engine

b) Marine engine

c) Aircraft engine

d) Lawnmower engine

Answer: c

Explanation: The centrifugal-type supercharger has been used mainly on aircraft engines, whereas the roots-type supercharger is used in automobile engines.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “ Petrol Engine Fuel Supply System – Turbocharger”.

1. Turbocharger is driven by which mechanism?

a) Intake gas

b) V-belt

c) Chain

d) Exhaust gas

Answer: d

Explanation: Both the supercharger and the turbocharger perform the same function, the supercharger is driven directly by the engine, whereas a turbocharger is driven by exhaust gas.

2. The exhaust gas drives which part of the turbocharger?

a) Intercooler

b) Turbine

c) Manifolds

d) Coupling

Answer: b

Explanation: Supercharger is mechanically driven by the engine, often through a belt connected to the crankshaft, whereas a turbocharger is powered by a turbine.

3. What is the disadvantage of turbocharger?

a) Turbo temperature

b) Hot air

c) Turbo drop

d) Throttle lag

Answer: d

Explanation: Throttle lag is the disadvantage of turbocharger. This occurs because turbocharger rely on the buildup of exhaust gas pressure to drive the turbine.

4. Which technology is the combination of turbocharging and supercharging an engine?

a) Twin-charging

b) Bi-lateral charging

c) Tripping

d) Maxcharging

Answer: a

Explanation: Compared with a mechanically driven supercharger, turbochargers tend to be more efficient, but less responsive. Twin-charger refers to an engine with both a supercharger and a turbocharger.

5. Which loss is increased when a turbocharger place exhaust back pressure on engines?

a) Fuel loss

b) Traction loss

c) Lubrication loss

d) Pumping loss

Answer: d

Explanation: A turbocharger does not place a direct mechanical load on the engine, although turbochargers place exhaust back pressure on engines, increasing pumping losses.

6. In a naturally aspirated engine, the air is drawn into the engine by which mechanism?

a) Supercharging

b) Turbocharging

c) Upward stroke of the piston

d) Downward stroke of the piston

Answer: d

Explanation: In naturally aspirated engines, intake gases are drawn into the engine by atmospheric pressure filling the volumetric void caused by the downward stroke of the piston.

7. What is the main objective of a turbocharger?

a) Volumetric efficiency

b) Thermal efficiency

c) Load

d) Fuel efficiency

Answer: a

Explanation: The objective of a turbocharger is to improve an engine’s volumetric efficiency by increasing the density of the intake gas allowing more power per engine cycle.

8. The turbocharger’s compressor draws in ambient air and compresses it before it enters into which part?

a) Intake manifold

b) Exhaust manifold

c) Air filter

d) Intake resonator

Answer: a

Explanation: The turbocharger’s compressor draws in ambient air and compresses it before it enters into the intake manifold at an increased pressure to the cylinder.

9. What are the systems that use a turbocharger to maintain an engine’s sea-level power output is known as?

a) CRDI engine

b) Multi-air engine

c) TDCI engine

d) Turbo-normalized engine

Answer: d

Explanation: Systems that use a turbocharger to maintain an engine’s sea-level power out are called turbo-normalized systems. Generally, it maintain a manifold pressure of 100KPa.

10. Smaller turbochargers have less turbo lag than a larger one?

a) True

b) False

Answer: a

Explanation: Smaller turbochargers have less turbo lag than larger ones, so often two small turbochargers are used instead of one large one. Hence, the statement is true.

11. Which type of turbochargers use moveable vanes to adjust air-flow?

a) Variable compressor

b) Variable- geometry

c) Variable-nozzle

d) Variable-nozzle or Variable-geometry

Answer: d

Explanation: Variable-geometry or variable-nozzle turbochargers use moveable vanes to adjust the air-flow to the turbine, imitating a turbocharger of the optimal size throughout the power curve.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Engine Performance”.

1. Which of the mentioned below is not an example of engine operating behavior?

a) Fuel consumption

b) Noise

c) Mechanical loading

d) Passenger loading

Answer: d

Explanation: The engine operating behavior in the speed load domain, for example, the behavior of emissions, fuel consumption, noise, mechanical and thermal loading.

2. Which of the mentioned below is a sensor to check the camshaft position?

a) CKP

b) CMP

c) VSS

d) CFK

Answer: b

Explanation: CKP is a crankshaft position sensor, CMP is a camshaft position sensor, VSS is a vehicle speed sensor, and APP is an acceleration pedal position.

3. Which of the mentioned below is a sensor to check the crankshaft position?

a) CKP

b) CMP

c) VSS

d) CFK

Answer: a

Explanation: CKP is a crankshaft position sensor. It is an electronic device used to monitor the position of the rotational speed of the crankshaft, to alter the ignition timing.

4. Which of the mentioned below is a sensor to check the acceleration pedal position?

a) AAP

b) ACC

c) APP

d) APS

Answer: c

Explanation: APP is an acceleration pedal position.This transmits the position of the accelerator pedal to the engine control unit to alter the amount of charge sent to the cylinder.

5. Which of the mentioned below is a sensor to check the vehicle speed sensor?

a) TPS

b) TSS

c) VPS

d) VSS

Answer: d

Explanation: VSS is a vehicle speed sensor. It is a type of tachometer, used to read the speed of a vehicle’s wheel rotation. It consists of a toothed ring and pickup.

6. Which of the mentioned below is a sensor to check the oxygen?

a) MAP

b) Knock sensor

c) TPS

d) Lambda sensor

Answer: d

Explanation: A lambda sensor is an oxygen sensor is an electronic device that measures the proportion of oxygen(O 2 ) in the exhaust gas or the liquid being analyzed.

7. Which sensor is fitted in the intake manifold?

a) MAP

b) TPS

c) Lambda sensor

d) APP

Answer: a

Explanation: The Manifold absolute pressure sensor  is one of the sensors used in an internal combustion engine’s electronic control system. Fitted in the intake manifold.

8. Which of the mentioned below is an actuator in engine performance?

a) Fuel injector

b) Lambda

c) TPS

d) Knock sensor

Answer: a

Explanation: Knock sensor, TPS, lambda sensors give input to the engine control unit and this decides the amount of fuel to be sprayed. The fuel injector is an actuator.

This set of Automotive Engine Auxiliary Systems Multiple Choice Questions & Answers  focuses on “Testing of Automobile Engine”.

1. Which test is used to determine the evaporative emissions from an engine?

a) Canister test

b) Cat aging test

c) Vibration test

d) SHED test

Answer: d

Explanation: SHED stands for Sealed Housing Evaporative Determination. This testing method allows for the measurement of evaporative emissions from an engine.

2. Which test is used to measure a coating’s resistance to abrasions?

a) Coating and paint testing

b) Gravelometer testing

c) Emission bench testing

d) Mechanical testing

Answer: b

Explanation: Gravelometer testing is another means of measuring a coating’s resistance to abrasions. In a gravelometer test, the samples have 300 pieces of gravel heaved at them by the machine’s air pressure.

3. Which test is used to determine, how quickly a catalytic converter’s effectiveness reduces?

a) Canister test

b) Cat aging test

c) Vibration test

d) SHED test

Answer: b

Explanation: To test how quickly a catalytic converter’s effectiveness reduces, a cat aging test has to be done. The catalytic converter is an essential component of the emission control system.

4. On which component driving creates constant vibrations?

a) Transmission

b) Cooling system

c) Vehicle frame

d) SHED

Answer: c

Explanation: Driving creates constant vibrations on the vehicle’s frame and components. This vibrations are transferred to passengers. To reduce this, vibration dampers are used.

5. Which test is used to determine the lifespan and foster premature wear of automobiles?

a) Climatic test

b) Cat aging test

c) Vibration test

d) SHED test

Answer: a

Explanation: The environment plays a substantial role in the lifespan of automobiles and their components. Certain climates have conditioned the foster premature wear.

6. Which gases cannot be measured in emissions bench testing?

a) Carbon monoxide

b) Carbon dioxide

c) Methane

d) Ethane

Answer: d

Explanation: A typical emissions bench can measure the greenhouse gas emissions, amounts of carbon monoxide, methane, hydrocarbons, nitrogen oxides, and carbon dioxide.

7. Which components are tested using pressure impulse testing?

a) Hydraulic components

b) Thermal components

c) Electrical components

d) Mechanical components

Answer: a

Explanation: Pressure impulse testing puts the system’s hydraulic components through their paces. Multiple systems use fluid movement to create mechanical motion.

8. Which test is used to examine engine performance and efficiency?

a) Hydraulic testing

b) Thermal testing

c) Electrical testing

d) Mechanical testing

Answer: d

Explanation: Automotive mechanical testing is used to examine engine performance and efficiency from a variety of systems. Dynamic analysis, stress testing, and more.