Automobile Engineering MCQ Solved Paper for UPSC CDS

1. Which one of the following statement correctly describes the construction of a bevel gear type differential?
A. The drive shafts are splined to the differential carrier.
B. The left side gear and the differential carrier rotate in constant unison.
C. The differential carrier houses differential pinion gears and side gears; each pinion gear meshes with a different side gear.
D. The differential carrier houses differential pinion gears and side gears
Answer : D

2. The main function of the brake fluid is
A. Lubrication
B. Power transmission
C. Cooling
D. None of these
Answer : B

3. The main task of a battery in automobiles is to
A. Supply electricity to the alternator
B. Act as a reservoir or stabilizer of electricity
C. Supply electricity to the vehicle's electrical system at all times while the engine is running
D. Supply a large amount of power to turn the starter motor when the engine is being started
Answer : D

4. The fuel pump of a programmed fuel injection (PFI) system operate for two seconds when the ignition is turned to the start position to
A. Enable the pump's fault diagnosis function to operate
B. Warm up and lubricate the pump
C. Supplies a large amount of fuel and thereby creates a choke effect
D. Pressurise the fuel system before the engine is started
Answer : D

5. The instrument used to check specific gravity of acid in a battery is
A. Hydrometer
B. Hygrometer
C. Anemometer
D. Multimeter
Answer : A

6. A basic difference between the spark ignition engine and the Diesel engine is that the
A. Diesel engine compresses air alone instead of an air-fuel mixture
B. Air temperature ignites the fuel in the Diesel engine
C. Fuel is sprayed into the combustion chamber in the Diesel engine as the piston nears T.D.C. on the compression stroke
D. All of the above
Answer : D

7. The function of a connecting rod is
A. To turn the flywheel
B. To drive the drive plate
C. To drive the fuel pump
D. To transmit motion of the piston to the crankshaft
Answer : D

8. If the air-fuel mixture ignites before the spark takes place at spark plug, the condition is called
A. Detonation
B. Ignition
C. Pre-ignition
D. Rumble
Answer : C

9. In petrol engines, during suction stroke, ________ is drawn in the cylinder
A. Air and fuel
B. Only fuel
C. Only air
D. None of these
Answer : A

10. An imbalance wheel during vehicle operation
A. Makes large noise when its heavy point hits the road surface
B. Deflects in the vehicle's longitudinal direction
C. Bounces vertically or deflects from side to side (as seen from front or rear)
D. Creates a standing wave
Answer : C

11. Two general types of tyres are
A. Tube type and tubeless
B. Solid and tubeless
C. Air and pneumatic
D. Split rim and drop centre
Answer : A

12. What type of bearing is used for main bearings and connecting rod bearings?
A. Ball bearings
B. Plain bearings
C. Needle roller bearing
D. Taper roller bearing
Answer : B

13. Highest useful compression ratio (HUCR) is the highest compression ratio at which the
A. Engine can run
B. Engine gives maximum output
C. Engine is most efficient
D. Fuel can be used in a test engine without knocking
Answer : D

14. With the increase of battery temperature, the specific gravity of electrolyte
A. Increases
B. Decreases
C. Remains the same
D. None of these
Answer : B

15. The function of a proportioning control valve (PCV) in a brake system is to
A. Ensure that equal pressure is supplied to the front and rear brakes throughout every braking operation
B. Reduce the brake fluid pressure when the brakes approach their lockup point
C. Cause less brake fluid pressure to act on the front brakes than on the rear brakes when the fluid pressure exceeds a predetermined level
D. Cause less brake fluid pressure to act on the rear brakes than on the front brakes when the fluid pressure exceeds a predetermined level.
Answer : D

16. The main function of an exhaust muffler is the
A. Optimisation of exhaust efficiency
B. Reduction of exhaust noise
C. Reduction of nitrogen oxide in the exhaust gases
D. Reduction of the exhaust gas volume
Answer : B

17. The function of antilock brake system (ABS) is that is
A. Reduces the stopping distance
B. Minimises the brake fade
C. Maintains directional control during braking by preventing the wheels from locking
D. Prevents nose dives during braking and thereby postpones locking of the wheels
Answer : C

18. The most commonly used supplementary restraint system (SRS) component is
A. Seat belt
B. Brake
C. Airbag
D. Steering
Answer : C

19. The component that connects the steering rack to the knuckles is
A. Tie rod
B. Sector gear
C. Pivot
D. Spline
Answer : A

20. The compression ratio for Diesel engines usually lies in the range of
A. 6-10
B. 10-1
C. 15-25
D. 25-40
Answer : C

21. The included angle is the sum of the
A. Camber and castor
B. Castor and S.A.I.
C. Camber and S.A.I.
D. Camber and toe in
Answer : C

22. If the engine coolant leaks into the engine oil, then engine oil
A. Appears milky
B. Become foamy
C. Turns black
D. None of these
Answer : A

23. The function of a radiator fan in the cooling system is that
A. It blows air through the radiator when necessary
B. It is turned by wind force as the vehicle moves forward, and its rotation drives the water pump
C. It cools the engine by blowing air onto the cylinder block
D. It draws heat out of the engine compartment
Answer : A

24. The air gap between the central electrode and ground (or side) electrode of a spark plug is around
A. 0.2 mm
B. 0.5 mm
C. 1 mm
D. 1.5 mm
Answer : C

25. The effect of having excess camber is
A. Excessive steering alignment torque
B. Hard steering
C. Too much traction
D. Uneven tyre wear
Answer : D

26. When the brake pedal free play is less than the specified value, then the
A. Brake drags
B. Brake fades
C. Vapour locking occurs in the brake lines
D. Antilock braking system malfunctions
Answer : A

27. In Diesel engines, the duration between the time of injection and the time of ignition is called
A. Spill cut-off
B. Delay period
C. Injection period
D. Ignition period
Answer : B

28. Two advantages of using helical gears rather than spur gears in a transmission system are
A. Strength and cost
B. Strength and less end thrust
C. Noise level and strength
D. Noise level and economy
Answer : C

29. Bead wires are made of
A. Steel
B. Copper
C. Zinc
D. Aluminium
Answer : A

30. The rolling resistance is because of the friction between the
A. Wheel rim and tyre
B. Tyre and the road surface
C. Wheel rim and road surface
D. None of these
Answer : B

31. The cetane rating of Diesel fuel is in the order of
A. 25
B. 45
C. 70
D. 90
Answer : B

32. An underinflated tyre will wear the tread most
A. Near the centre
B. Near the edges
C. In the lateral direction
D. In the cross direction
Answer : B

33. The function of a governor in automobiles is to
A. Limit the power
B. Limit the vehicle speed
C. Maintain constant engine speed
D. Maximise the fuel economy
Answer : B

34. The fuel pump in the programmed fuel injection (PFI) system is located
A. Between the fuel filler pipe and fuel tank
B. In the fuel tank
C. On the distributor mounting in the engine compartment
D. On the engine compartment bulkhead
Answer : B

35. The parking brakes employed in vehicles are operated
A. Mechanically
B. Hydraulically
C. Pneumatically
D. None of these
Answer : A

36. The Diesel engines as compared to petrol engines require
A. Bigger flywheel
B. Smaller flywheel
C. Same size of flywheel
D. No flywheel
Answer : A

37. The negative plates of a lead acid battery has
A. Lead peroxide (PbO?)
B. Spongy lead (Pb)
C. Lead sulphate (PbSO?)
D. Sulphuric acid (H?SO?)
Answer : B

38. The tilting of the front wheels away from the vertical, when viewed from the front of the car, is called
A. Camber
B. Caster
C. Toe in
D. Toe out
Answer : A

39. The valve tappet clearance is measured by
A. Screw pitch gauge
B. Engineering scale
C. Feeler gauge
D. Vernier caliper
Answer : C

40. In a four speed four stroke Diesel engine, the intake valve
A. Opens at T.D.C. and closes at B.D.C.
B. Opens at 20° before T.D.C. and closes at 35° after B.D.C.
C. Opens at 10° after T.D.C. and closes at 20° before B.D.C.
D. None of the above
Answer : B

41. The fuel that detonates easily, is
A. N-heptane
B. Iso-octane
C. Benzene
D. Alcohol
Answer : A

42. The device for smoothening out the power impulses from the engine is called
A. Clutch
B. Differential
C. Flywheel
D. Torque converter
Answer : C

43. An overinflated tyre will wear the tread most near the
A. Edges
B. Corners
C. Centre
D. None of these
Answer : C

44. The advantage of a tubeless tyre over tube type tyre is
A. Slow air leakage
B. Better fuel efficiency
C. Less chances of running flat
D. All of these
Answer : D

45. The ease with which petrol vaporizes is called its
A. Oxidation
B. Octane number
C. Volatility
D. Cetane number
Answer : C

46. When the piston is at T.D.C, the volume above the piston in the combustion chamber is the
A. Clearance volume
B. Cylinder volume
C. Exhaust volume
D. None of these
Answer : A

47. The heat transfer from coolant to air in the radiator of an automobile engine takes place by
A. Radiation only
B. Convention only
C. Convection and radiation
D. Conduction, convection and radiation
Answer : C

48. The engine oil level should be checked
A. Immediately after the ignition switch is turned off
B. While the engine is running
C. A few minutes after the ignition switch is turned off
D. While the engine is running at high idle speed
Answer : C

49. A traction control system (TCS) in automobiles controls the
A. Vibrations on the steering wheel
B. Engine power during acceleration
C. Torque that is transmitted by the tyres to the road surface
D. Stopping distance in case of emergency
Answer : C

50. In bias ply tyres
A. All plies run parallel to one another
B. Belts of steel mesh are used in the tyres
C. One ply layer runs diagonally one way and another layer runs diagonally the other way
D. All of the above
Answer : C