Internal Combustion Engines MCQs

Question 1

Ignition lag is

Accepted Answer

The time taken by fuel after injection (before top dead centre) to reach upto auto-ignition temperature

Answer

Time before actual fuel injection and the pump plunger starts to pump fuel

Answer

Time corresponding to actual injection and top dead centre

Answer

Time corresponding to actual ignition and top dead centre

Question 2

The spark plug gap is normally maintained at

Accepted Answer

0.45 to 0.6 mm

Answer

0.1 to 0.2 mm

Answer

0.2 to 0.4 mm

Answer

0.6 to 0.8 mm

Question 3

The function of a fuel pump in a petrol pump is to

Accepted Answer

Pump fuel so that it reaches carburetor

Answer

Inject fuel in cylinder

Answer

Supply fuel when carburettor fails

Answer

Improve thermal efficiency

Question 4

The delay period in petrol engine is of the order of

Accepted Answer

0.002 sce

Answer

0.001 sec

Answer

0.01 sec

Answer

0.05 sec

Question 5

Detonation is caused by the following unstable compounds

Accepted Answer

Peroxides, aldehydes and ketones

Answer

Peroxides, aldehydes, oxides and sulphides

Answer

Aldehydes, oxides and ketones

Answer

Ketones and sulphur compounds

Question 6

If overhead clearance is less, then the following type of engine should be selected

Accepted Answer

Horizontal

Answer

V-type

Answer

In-line

Answer

Vertical

Question 7

Which is false statement about advantages of V-type engine

Accepted Answer

Less overhead clearance

Answer

Compact design requiring lesser space

Answer

Casting less liable to distortion

Answer

Reduced torsional vibration because of shorter crankshaft

Question 8

The pistons are usually given a coating such as tin plating in order to

Accepted Answer

Reduce possibility of scoring reduce friction

Answer

Reduce weight

Answer

Conduct heat efficiently

Answer

Increase lubrication effect

Question 9

Piston rings are usually made of

Accepted Answer

Cast iron

Answer

Aluminium

Answer

Phosphor bronze

Answer

Babbitt