Automobile Engineering 1000+ MCQ with answer for UPSC CSE

1. The cetane number of a Diesel fuel is a measure of
A. Volatility
B. Viscosity
C. Ignition quality
D. Delay period
Answer : D

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

3. 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

4. A heat treated glass generally used in automobiles bursts into ________ upon cracking,
A. Sharp edged fragments
B. Small particles
C. Large particles
D. None of these
Answer : B

5. The function of an oil control orifice is that it
A. Returns cylinder head lubricating oil to the oil pan at high speed
B. Turns oil into fine mist for spray lubrication
C. Regulates the pressure of engine oil supplied by the oil pump for the lubrication of cylinder head mechanism and other purposes
D. Removes impurities from cylinder head lubricating oil
Answer : C

6. Which of the following parameter can be adjusted by modifying the tie rod attachment length?
A. Camber
B. Caster
C. Toe
D. Steering gear ratio
Answer : C

7. The parking brake generally acts on
A. Front wheels
B. Rear wheels
C. Front and rear wheels
D. Propeller shaft
Answer : B

8. If the spark plug deposit indicates black coating of soot, it indicates that the engine has been generally operating on
A. Too lean mixture
B. Stoichiometric mixture
C. Most economical mixture
D. Too rich mixture
Answer : D

9. The function of a second ring is that it is a
A. Back up compression ring which will work in place of the top ring when it is broken
B. Compression ring and aids the top ring in sealing and cooling
C. Back up oil control ring which will work in place of the bottom ring when it is broken
D. Cushion ring which prevents piston slap and knock
Answer : B

10. The connecting rods are generally made of ________ shaped crosssection.
A. I
B. C
C. L
D. H
Answer : A

11. The power actually developed inside the engine cylinder is called as
A. Indicated power
B. Brake power
C. Frictional power
D. None of these
Answer : A

12. The connecting rod connects the piston and the
A. Cylinder head
B. Cylinder block
C. Camshaft
D. Crankshaft
Answer : D

13. The oil pump is driven by the
A. Camshaft
B. Alternator shaft
C. Crankshaft via drive belt
D. Crankshaft directly
Answer : D

14. Damper is also known as
A. Shock absorber
B. Torsion bar
C. Spring
D. Radius rod
Answer : A

15. The maximum torque multiplication ratio in a torque converter is about
A. 2.5
B. 10
C. 25
D. 40
Answer : A

16. 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

17. 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

18. The octane rating of petrol commercially available is
A. 85-95
B. 95-100
C. 100-110
D. 110-125
Answer : A

19. The Diesel engine works on
A. Otto cycle
B. Carnot cycle
C. Diesel cycle
D. Rankine cycle
Answer : C

20. The discharged lead acid battery has on its plates
A. Lead peroxide (PbO?)
B. Spongy lead (Pb)
C. Lead sulphate (PbSO?)
D. Sulphuric acid (H?SO?)
Answer : C

21. In order to implement gear changes in the gear unit of an automatic transmission, a ________ is used.
A. Synchronizer
B. Planetary gear
C. Magnetic clutch
D. Hydraulic multi plate clutch
Answer : D

22. The ignition in a spark ignition engine takes place when the piston is
A. Exactly at the T.D.C. position on its compression stroke
B. Approaching the T.D.C. position on its compression stroke
C. Leaving the T.D.C. position on its compression stroke
D. Approaching the T.D.C position on its exhaust stroke
Answer : B

23. In which of the following conditions, the idle CO percentage should be measured with the vehicle?
A. Headlights and other electrical devices are switched off
B. Headlights and other electrical devices are switched on
C. Headlights and other lights are switched off
D. Headlights are switched on
Answer : A

24. The difference between DOT 3 and DOT 4 brake fluids is
A. DOT 4 fluids have a higher boiling point than DOT 3 fluid
B. DOT 4 fluids have a lower boiling point than DOT 3 fluid
C. DOT 3 and DOT 4 fluids have the same boiling point, but DOT 4 fluid has a longer service life
D. DOT 4 fluid is more resistant to freezing than DOT 3 fluid
Answer : A

25. If a tyre is designated as 175/65 R-14 82-S, then the aspect ratio for the tyre is
A. 175
B. 65
C. 14
D. 82
Answer : B

26. The Diesel engines are also known as
A. Spark ignition (S.I.) engines
B. Compression ignition (C.I.) engines
C. Steam engines
D. None of these
Answer : B

27. The basic purpose of tyre rotation on automobiles is to
A. Avoid ply separation
B. Equalize wear
C. Get better ride
D. None of these
Answer : B

28. The starter motor is driven by
A. Chain drive
B. Gear drive
C. Flat belt drive
D. V-belt drive
Answer : B

29. The damper fluid leakage typically occur from
A. Upper damper mounting
B. Bottom of damper
C. Clearance between inner and outer tubes of damper
D. Coil spring mounting
Answer : C

30. The purpose of a thermostat in an engine cooling system is to
A. Prevent the coolant from boiling
B. Allow the engine to warm up quickly
C. Indicate the coolant temperature
D. Pressurise the system to raise the boiling point
Answer : B

31. The engine oil viscosity is defined by _________ ratings.
A. Automatic transmission fluid (ATF)
B. Society of automotive engineers (SAE)
C. Gross vehicle weight (GVW)
D. American petroleum institute (API)
Answer : B

32. A petrol engine of a car develops 125 Nm torque at 2700 r.p.m. The car is driven in second gear having gear ratio of 1.75. The final drive ratio is 4.11. If the overall transmission efficiency is 90%, then the torque available at the driving wheels is
A. 8.091 Nm
B. 80.91 Nm
C. 809.1 Nm
D. 8091 Nm
Answer : C

33. The acid used in automobile battery is
A. Hydrochloric acid
B. Hydrofluoric acid
C. Nitric acid
D. Sulphuric acid
Answer : D

34. The valve overlap in four stroke petrol engines is approximately
A. 30°
B. 60°
C. 90°
D. 120°
Answer : A

35. 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

36. When the front wheels of a vehicle are locked during braking, then
A. Stopping distance becomes extremely long
B. Front tyres skid across the road surface, and the vehicle spins around
C. Rear tyres skid across the road surface, and the vehicle spins around
D. Driver loses control over the steering, and the vehicle continues moving in its current direction
Answer : D

37. When indicated power (I.P.) and frictional power (F.P.) are known, we can calculate
A. Brake power
B. Compression ratio
C. Specific air consumption
D. Mean effective pressure
Answer : A

38. The component that is responsible for converting the rotation of the steering wheel into lateral motion is the
A. Steering wheel
B. Steering shaft
C. Steering gearbox
D. Tie rod
Answer : C

39. The seat belt tensioners are built in the
A. Front seats
B. Shoulder anchors
C. Seat belt retractors
D. Seat belt buckles
Answer : C

40. In radial tyres
A. One ply layer runs diagonally one way and another layer runs diagonally the other way
B. All plies run parallel to one another and vertical to tyre bead
C. Inner tubes are always used
D. None of these
Answer : B

41. 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

42. In comparison with a radial tyre, one advantage of a bias ply tyre is
A. Longer life
B. Lower rolling resistance
C. Smoother ride at low speeds
D. None of these
Answer : C

43. The path taken by intake air is
A. Carburettor (or throttle body) air cleaner intake manifold intake ports cylinders
B. Air cleaner carburettor (or throttle body) intake ports intake manifold cylinders
C. Air cleaner intake manifold carburettor (or throttle body) intake ports cylinders
D. Air cleaner carburettor (or throttle body) intake manifold intake ports cylinders
Answer : D

44. Clutch facings are usually attached to the plate by
A. Steel rivets
B. Brass rivets
C. Aluminium screws
D. Steel screws
Answer : B

45. 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

46. The timing belt is attached to the camshaft pulley and
A. Timing belt drive pulley
B. Distributor
C. Radiator fan pulley
D. Alternator pulley
Answer : A

47. Which one of the following statements correctly describes the construction of a planetary gear type differential?
A. The six planetary pinions rotate in constant mesh with the internal gears.
B. One drive shaft is splined to the central gear and the other to the planetary gear.
C. Each planetary pinion gear meshes with both the central gear and the internal gear.
D. The internal gear is fixed to the planetary gear.
Answer : B

48. The tyre rotation is generally done at
A. 1000 km
B. 4000 km
C. 6000 km
D. 10000 km
Answer : D

49. In aluminium cylinder blocks, the cylinder liners are made of
A. Aluminium
B. Ceramic
C. Brass
D. Cast iron
Answer : D

50. Which of the following indicates multigrade oil?
A. SAE 30
B. API SF
C. SAE 20 W50
D. API 50
Answer : C