Explore topic-wise MCQs in Automobile Engineering.

This section includes 315 Mcqs, each offering curated multiple-choice questions to sharpen your Automobile Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

The most popular firing order in case of cylinder in-line IC engine is

A. 1-2-3-4
B. Alcohol
C. 1-4-2-3
D. 4-3-2-1
E. 1-3-4-2
Answer» F.
Discussion
2.

Maximum danger of ol dilution by fuel in an engine occurs when

A. Engine is running at overload
B. Engine is running at rated load
C. Engine is running on lean mixture
D. Choke circuit is cut in for too long a period
E. All of the above
Answer» E. All of the above
Discussion
3.

Which one of the followings is used in S.I. engines?

A. spark plug
B. injector
C. cross-head
D. none of the above
E. None of the above
Answer» B. injector
Discussion
4.

A stratified charged engine provides

A. air fuel mixture of different air-fuel ratios at various places on the combustion chamber
B. different air fuel ratios in consecutive strokes
C. different air fuel ratios at different times depending upon the load
D. none of the above
E. None of the above
Answer» B. different air fuel ratios in consecutive strokes
Discussion
5.

If a lead acid battery is fully charged at specific gravity of 1.28 and fully discharged at specific gravity of 1.11 then at specific gravity of 1.19, the battery will be

A. nearly fully charged
B. more than 50% charged
C. 50% charged
D. less than 50% charged
E. None of the above
Answer» E. None of the above
Discussion
6.

Too early ingition in SI engine will cause

A. pinking, power loss
B. hotter running, power loss
C. power loss, higher fuel consumption
D. none of the above
E. None of the above
Answer» B. hotter running, power loss
Discussion
7.

Generally speaking for better efficiency of IC engine the valves must

A. open before the beginning of a stroke and close before the end of a stroke
B. open after the beginning of a stroke and close before the end of a stroke
C. open after the beginning of a stroke and close after the end of a stroke
D. open before the beginning of a stroke and close after the end of a stroke
E. None of the above
Answer» E. None of the above
Discussion
8.

Deposit of carbon in the exhaust system

A. Will have no effect on back pressure
B. Will reduce back pressure
C. Will increase back pressure
D. Will result in black smoke
E. Will increase noise level
Answer» D. Will result in black smoke
Discussion
9.

The angle between the cord and the centre line of the tread is called

A. tread angle
B. side wall angle
C. crown angle
D. none of the above
E. None of the above
Answer» D. none of the above
Discussion
10.

The inlet value remains open approximately for

A. 160?
B. 180?
C. 190?
D. 235?
E. None of the above
Answer» E. None of the above
Discussion
11.

As a rule, before the pistons are removed it is necessary to remove the

A. Piston rings
B. Circlip
C. Camshaft
D. Crankshaft
E. Gudgeon pin
Answer» B. Circlip
Discussion
12.

Castor is

A. forward tilt of the king pin
B. backward tilt of the king pin
C. either of (A) and (B) above
D. none of the above
E. None of the above
Answer» D. none of the above
Discussion
13.

Too rich mixture for a S.I. engine means air : fuel ratio of about

A. 15 ; 1
B. 13 ; 1
C. 17 ; 1
D. 14 ; 1
E. 10 ; 1
Answer» F.
Discussion
14.

Gum content of petroleum fuels is mainly due to

A. concentration of sulphides and disulphides
B. evaporation loss of lighter fractions
C. oxidation of unsaturated bydrocarbons
D. All of the above
E. None of the above
Answer» D. All of the above
Discussion
15.

During idling in a CI engine, the air fuel ratio may be of the order of

A. 30
B. 10
C. 15
D. 20
E. 5
Answer» B. 10
Discussion
16.

Air injection in case of S.I. engine refers to injection of

A. Doesn't exist
B. Liquid fuel only
C. Air only
D. Air and fuel mixture
E. Super charging
Answer» C. Air only
Discussion
17.

The number of exhaust manifolds in a V-8 engine

A. Eight
B. One
C. There is no exhaust manifold
D. Two
E. Four
Answer» E. Four
Discussion
18.

The instrument used to check the state of charge of a battery is

A. Battery eliminator
B. Hygrometer
C. Hydrometer
D. Anemometer
E. Battery charger
Answer» D. Anemometer
Discussion
19.

Which fully charged the specific gravity of acid in a battery is usually

A. 1.28
B. 1.12
C. 0.74
D. 0.84
E. 1
Answer» B. 1.12
Discussion
20.

A spark voltage needs a voltage of

A. 440 V
B. 220 V
C. 12 V
D. 24 V
E. 5000 - 15000 V.
Answer» F.
Discussion
21.

Which of the following hydrocarbon has ring structure?

A. Paraffin
B. Olefin
C. Diolefin
D. Naphthene
E. None of the above
Answer» E. None of the above
Discussion
22.

The device for smoothening out the power inpulses from the engine is called

A. Clutch
B. Differential
C. Flywheel
D. Gear box
E. Torque convertor
Answer» D. Gear box
Discussion
23.

During discharge of a battery, the sulphuric acid in the electrolyte is replaced by

A. Lead sulphate
B. Water
C. Hydrogen
D. Ions
E. Oxygen
Answer» C. Hydrogen
Discussion
24.

In transmission system if the reverse gear slips out, the probable cause could be

A. Reverse sliding gear teeth worn out
B. Main shaft spines worn
C. Reverse idler gear teeth worn
D. Insufficient gear mesh
E. Any of the above
Answer» F.
Discussion
25.

CFR engine is a

A. high speed engine
B. multi-cylinder four stroke engine
C. 2 and 4 stroke engine
D. variable compression ratio engine
E. None of the above
Answer» E. None of the above
Discussion
26.

Brake lining is mounted on

A. Brake shoe
B. Brake drum
C. Master cylinder
D. Wheel cylinder
E. Any of the above
Answer» B. Brake drum
Discussion
27.

The spark advance in SI engine is adjusted to obtain maximum pressure

A. 10 - 12? past TDC
B. at TDC
C. 10 - 12? before TDC
D. none of the above
E. None of the above
Answer» B. at TDC
Discussion
28.

In a Diesel engine, the temperature of gases under full load may be of the order of

A. 100?C
B. 900-1000?C
C. 150-200?C
D. 200-300?C
E. 500-550?C
Answer» F.
Discussion
29.

Water in lubricating oil aids in

A. Burning
B. Dilution
C. Formation of solution
D. Oxidation
E. Decomposition
Answer» D. Oxidation
Discussion
30.

In case of oil bath type air cleaner, the oil sediments formed by the dust must be removed

A. Monthly
B. After about 500 km
C. Weekly
D. After about 5000 km
E. Every day
Answer» E. Every day
Discussion
31.

The octane rating of petrol commercially available is usually

A. 110 - 125
B. 90 - 100
C. 100 - 105
D. 125 - 140
E. 85 - 90
Answer» F.
Discussion
32.

Which of the following action reduces the life of tyre?

A. Low air pressure
B. Extra load
C. Frequent braking
D. All of the above
E. None of the above
Answer» E. None of the above
Discussion
33.

Exhaust valve temperature is about

A. 1000?C
B. 150?C
C. 500?C
D. 100?C
E. 35?C
Answer» D. 100?C
Discussion
34.

The exhaust value of a four stroke I.C. engine should open

A. exactly at the end of expansion stroke
B. slightly after the end of expansion stroke
C. slightly before the end of expansion stroke
D. none of the above
E. None of the above
Answer» D. none of the above
Discussion
35.

Accumulation of rust and scale in the engine cooling system will cause

A. Reduced output
B. Overheating
C. Slow warm up
D. Low exhaust temperature
E. More noise
Answer» C. Slow warm up
Discussion
36.

A hot plug has a

A. Heat dam
B. Short heat path
C. Long insulator
D. Long heat path
E. Short insulator
Answer» B. Short heat path
Discussion
37.

Excess oil consumption in engine may be due to

A. Leakage of oil through oil pan gasket
B. Poor quality or improper viscosity of engine oil
C. Excessive oil pressure
D. Badly worn piston rings
E. Any of the above
Answer» F.
Discussion
38.

Diesel engine as compared to petrol engines require

A. Biggenr flywheels
B. Same size flywheel
C. Smaller flywheel
D. Flywheel whose size may be less or more depending on several other factors
E. No flywheel
Answer» B. Same size flywheel
Discussion
39.

The heating value of diesel is approximately

A. 7500 kcal/kg
B. 6500 kcal/kg
C. 10,000 kcal/kg
D. 8500 kcal/kg
E. 125000 kcal/kg
Answer» D. 8500 kcal/kg
Discussion
40.

In case of friction clutch the coefficient of friction is expected to be

A. 0.4 to 0.5
B. 0.85 to 0.90
C. 0.1
D. 0.01
E. 0.15 to 0.17
Answer» B. 0.85 to 0.90
Discussion
41.

Common causes for excessive oil consumption include

A. Defective radiator
B. Short trips and cold weather
C. Heavy oil and light bearings
D. Frequent oil changes
E. High speed and worn engine
Answer» F.
Discussion
42.

Which oil is more viscous

A. SAE 50
B. SAE 40
C. SAE 70
D. SAE 80
E. SAE 30
Answer» E. SAE 30
Discussion
43.

In a Diesel engine the fuel injection pressure is usually in the range

A. 20 to 25 atm
B. 10 to 15 atm
C. 30 to 40 atm
D. 60 to 70 atm
E. 100 to 170 atm
Answer» F.
Discussion
44.

Grease cannot be used as lubricant for the lubrication of

A. Front wheel bearings
B. Slip joint
C. Input shaft
D. Coolant pump
E. Transmission
Answer» F.
Discussion
45.

In case of petrol engines, into the engine cylinder during suction stroke

A. air and fuel is drawn
B. only fuel is drawn
C. only air is drawn
D. none of the above
E. None of the above
Answer» B. only fuel is drawn
Discussion
46.

The centrifugal advance mechanism is located

A. One the camshaft
B. In the camshaft gear
C. In the distributor
D. On the crankshaft balancer
E. At the drive gear
Answer» D. On the crankshaft balancer
Discussion
47.

In a typical medium speed 4-stroke cycle diesel engine, the inlet value

A. Opens at 20? before TDC and closes at 35? after BDC
B. Opens at TDC and closes at BDC
C. Opens at 10? after TDC and closes at 20? after BDC
D. Remains open for 200?C
E. None of the above
Answer» B. Opens at TDC and closes at BDC
Discussion
48.

The advanctage of stratified charge engine is

A. better part load efficiency
B. resistance to knocking tendency
C. better volumetric efficiency
D. All of the above
E. None of the above
Answer» E. None of the above
Discussion
49.

Commonly used antifeeze solution in automobiles is

A. Freon 12
B. Ammonium chloride
C. Carbon disulphide
D. Liquid ammonia
E. Gloycol
Answer» F.
Discussion
50.

For flow of petrol from fuel tank to the carburettor, the fuel system includes

A. A vacuum pump
B. A suction pump
C. A float
D. A fuel pump
E. An acceleration pump
Answer» E. An acceleration pump
Discussion