Internal Combustion Engines MCQs

Question 1

The detonating tendency in petrol engines increases with

Accepted Answer

Increase of compression ratio

Answer

Decrease of compression ratio

Answer

Increase of engine speed

Answer

Decrease of engine speed

Question 2

The antifreeze solution commonly used in automobiles is

Accepted Answer

Glycol

Answer

Normal-heptane

Answer

Iso-octane

Answer

Lead ethyl

Question 3

The power to weight ratio in a two stroke engine as compared to four stroke engine is

Accepted Answer

More

Answer

Less

Answer

Equal

Answer

Depends on the power rating

Question 4

Freezing temperature of petrol is of the order of

Accepted Answer

-50 to -30°C

Answer

-40 to 0°C

Answer

-20 to -10°C

Answer

-30 to -20°C

Question 5

Injection lag in diesel engines is caused by

Accepted Answer

All of the above

Answer

Expansion of fuel-oil discharge lines under high pressure

Answer

Compressibility of fuel

Answer

Leakage past the fuel-oil plunger

Question 6

Pistons of diesel engines are usually cooled by

Accepted Answer

Lubricating oil

Answer

Water

Answer

Air

Answer

Fuel oil

Question 7

In order to reduce wear and eliminate scuffing, the piston rings are

Accepted Answer

Plated with chromium or cadmium

Answer

Made of cast iron

Answer

Lubricated

Answer

Provided with stepped groove

Question 8

The back pressure of petrol engine is usually of the order of

Accepted Answer

1.2 ata

Answer

1.0 ata

Answer

0.8 ata

Answer

0.5 ata

Question 9

The cause of smoky exhaust in a diesel engine could be

Accepted Answer

All of the above

Answer

Fuel is not distributed equally to all the cylinders

Answer

Fuel injection is late or fuel injector is not adjusted right

Answer

Water in the fuel