Internal Combustion Engines MCQs

Question 1

The ignition coil in diesel engines produces voltage of the order of

Accepted Answer

20,000 volts

Answer

6 to 12 volts

Answer

240 volts

Answer

1000 volts

Question 2

If the door of a diesel engine crankcase is opened just after shutdown before cooling of engine, then

Accepted Answer

There is a risk of explosion taking place

Answer

Efficiency of engine will be poor

Answer

It is the safest practice

Answer

Some parts may be subjected to thermal stresses

Question 3

The thermal efficiency of a diesel engine is of the order of

Accepted Answer

34%

Answer

92%

Answer

68%

Answer

52%

Question 4

Theoretically, the following engine should have maximum efficiency

Accepted Answer

4-stroke C.I. engine

Answer

Gas engine

Answer

4-stroke S.I. engine

Answer

Steam engine

Question 5

The part load efficiency of a carburetor is,

Accepted Answer

Poor

Answer

Maximum

Answer

Optimum

Answer

Constant

Question 6

In petrol engine using a fixed octane rating fuel and fixed compression ratio, supercharging will

Accepted Answer

Increase the knocking tendency

Answer

Decrease the knocking tendency

Answer

Not affect the knocking tendency

Answer

Increase or decrease knocking tendency depending on strength and time of spark

Question 7

In open combustion chamber in diesel engines

Accepted Answer

The shape and layout of the piston crown, the inlet port, and the valve produce the turbulent effect on fuel mixture

Answer

Fuel is injected into an auxiliary chamber that is separated from the cylinder by an orifice or throat

Answer

Only a part of air charge is contained in an auxiliary chamber in which the fuel starts to burn with insufficient air which due to explosion tendency mixes thoroughly into main cylinder charge

Answer

Fuel is injected at atmospheric pressure

Question 8

The basic requirement of a good combustion chamber is

Accepted Answer

High power output and high thermal efficiency

Answer

High compression ratio

Answer

Low volumetric efficiency

Answer

Minimum turbulence

Question 9

Deposition of carbon in petrol engine cylinder would result in increase of

Accepted Answer

Compression ratio

Answer

Clearance volume

Answer

Swept volume

Answer

Volumetric efficiency