Automobile Engineering 1000+ MCQ with answer for XAT

1. 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

2. The aluminium alloy is used in cylinder blocks because
A. It is lighter and has good heat dissipation characteristics
B. Material cost is low
C. It does not require any cylinder liners
D. The piston is also made of aluminium alloy
Answer : A

3. 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

4. When turning a corner
A. The front wheels are toeing out
B. The front wheels are turning on different angles
C. The inside front wheels has a greater angle than the outside wheel
D. All of the above
Answer : D

5. The formula for Isooctane is
A. C8H18
B. C7H17
C. C6H18
D. C7H18
Answer : A

6. 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

7. The mechanical efficiency (?m) of an I.C. engine is equal to (where I.P. = Indicated power, B.P. = Brake power and F.P. = Frictional power)
A. I.P/B.P.
B. B.P/I.P.
C. B.P/F.P.
D. F.P/B.P.
Answer : B

8. The exhaust gas from petrol engine contains
A. Petrol vapours
B. Water vapours
C. Carbon monoxide
D. All of these
Answer : D

9. The negative terminal post on the top of a battery is
A. Smaller than the positive terminal post
B. Larger than the positive terminal post
C. Of the same size as the positive terminal post
D. None of these
Answer : A

10. 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

11. The characteristic that is enhanced by the honing of cylinder sleeves inner surface is
A. Cooling efficiency
B. Resistance to wear
C. Lubrication performance
D. None of these
Answer : C

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

13. The self ignition temperature of Diesel as compared to petrol is
A. Higher
B. Lower
C. Same
D. Depends on fuel quality
Answer : B

14. The vehicle ride will be comfortable if
A. Unsprung mass is kept minimum
B. Sprang mass is kept minimum
C. Vehicle mass is kept minimum
D. All of these
Answer : A

15. A front stabilizer bar is used to
A. Increase vehicle load carrying capacity
B. Provide a softer ride
C. Control suspension movement and body roll
D. All of the above
Answer : C

16. Which of the following symptom is caused as a result of brake disc run out?
A. Ineffectiveness of the brakes
B. Judder during braking
C. Localized wearing of the brake pads
D. Rapid wearing of the brake pads
Answer : B

17. If clearance volume of I.C. engines is increased, the compression ratio will
A. Increase
B. Decrease
C. Remain constant
D. Be doubled
Answer : B

18. 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

19. The purpose of transmission in an automobile is
A. To vary the speed of automobile
B. To vary the torque at the wheels
C. To vary the power of automobile
D. None of these
Answer : B

20. A laminated glass upon cracking
A. Bursts into sharp edged fragments
B. Bursts into granular pieces
C. Sandwiched layer traps the fragments
D. Breaks into the form of crystals
Answer : C

21. Incorrect steering axis inclination (S.A.I.) causes
A. Tendency to assume toe-out orientation
B. Generation of a braking effect at tight corners
C. Poor recovery of the steering wheel after making a turn
D. The vehicle to pull to the side of lesser inclination
Answer : C

22. Two speed reverse gear arrangements is generally provided in case of
A. Passenger cars
B. Matadors
C. Tractors
D. Trucks
Answer : C

23. 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

24. 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

25. The main function of intake manifold is that it
A. Promotes the mixture of air and fuel
B. Reduces intake noise
C. Cools the intake air to a suitable temperature
D. Distributes intake air equally to the cylinders
Answer : D

26. Which of the following bulb in a car will have the least wattage?
A. Head light bulb
B. Stop light bulb
C. Parking light bulb
D. Ignition warning bulb
Answer : D

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

28. An oil filter bypass valve opens when the
A. Engine is cold
B. Engine overheats
C. Oil filter becomes clogged
D. Engine runs at high speed
Answer : C

29. 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

30. The engine oil is stored in __________ when the engine is not running.
A. Oil pan
B. Cylinder head
C. Oil pump
D. Separate oil tank
Answer : A

31. The function of positive crankcase ventilation (PCV) system is that it
A. Mixes fuel with air
B. Promotes combustion by creating a swirling movement in the air-fuel mixture
C. Returns blow by gases from the crankcase to the intake system
D. Feeds blow by gases to the exhaust manifold
Answer : C

32. In a petrol engine, the high voltage for spark plug is in the order of
A. 1000 volts
B. 2000 volts
C. 11 kilovolts
D. 22 kilovolts
Answer : D

33. The number of exhaust manifolds in a V6 engine is
A. One
B. Two
C. Four
D. Eight
Answer : B

34. 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

35. In a four wheel drive (4WD), the numbers of gear boxes are
A. 1
B. 2
C. 3
D. 4
Answer : B

36. The natural gas is compressed in a CNG cylinder at a pressure of
A. 200 bar
B. 220 bar
C. 250 bar
D. 300 bar
Answer : A

37. In Spark Ignition Engine
A. Only air is introduced into the cylinder
B. The mixture of air and fuel is introduced into the cylinder from carburettor
C. Both A and B
D. None of these
Answer : B

38. 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

39. The connecting rod lower end is connected to the relevant ________ of crankshaft.
A. Big end
B. Crank arm
C. Journal
D. Small end
Answer : C

40. 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

41. The problems caused by the wheel imbalance are
A. Hard steering and hard ride
B. Poor acceleration and hard steering
C. Steering wheel vibrations and uneven tyre wear
D. Poor acceleration and reduced fuel efficiency
Answer : C

42. The most effective method of controlling S.I. engine exhaust emission is by
A. Recirculating exhaust
B. Using catalytic converter
C. Using some additives in the fuel
D. None of these
Answer : B

43. 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

44. The two rows of cylinders in a 'V' type engine are generally arranged at
A. 45°
B. 60°
C. 90°
D. 130°
Answer : B

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

46. The service brakes employed in cars are generally operated
A. Mechanically
B. Hydraulically
C. Pneumatically
D. None of these
Answer : B

47. For the same maximum pressure and temperature
A. Diesel cycle is more efficient than Otto cycle
B. Otto cycle is more efficient than Diesel cycle
C. Both Otto cycle and Diesel cycle are equally efficient
D. None of the above
Answer : A

48. The positive 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 : A

49. The firing order for an inline four cylinder I.C. engine is
A. 1-2-3-4
B. 1-3-4-2
C. 1-2-4-3
D. 1-3-2-4
Answer : B

50. The temperature indicating instrument in vehicles indicates the temperature of
A. Engine piston
B. Engine cylinder
C. Lubricating oil
D. Jacket cooling water
Answer : D