Internal Combustion Engines MCQs

Question 1

For spark ignition engines, fuels in order of decreasing knock tendency are

Accepted Answer

Paraffins, napthenes, aromatics

Answer

Napthenes, paraffins, aromatics

Answer

Paraffins, aromatics, napthenes

Answer

Aromatics, paraffins, napthenes

Question 2

Tendency of detonation in S.I. engines increases with

Accepted Answer

Increase of compression ratio

Answer

Decrease of engine speed

Answer

Increase of engine speed

Answer

Decrease of compression ratio

Question 3

Antiknock for compression ignition engines is

Accepted Answer

Tetra ethyl lead

Answer

Amyl nitrate

Answer

Ethylene dibromide

Answer

Napthene

Question 4

Detonation in petrol engines can be suppressed or reduced by the addition of small quantity of

Accepted Answer

Lead ethide

Answer

Iso-octane

Answer

N-heptane

Answer

Methyl napthalene

Question 5

It is possible to obtain a number of blends of the fuel by mixing/blending

Accepted Answer

Cetane with α-methyl napthalene

Answer

Cetane with iso-octane

Answer

Cetane with aldehydes and ketones

Answer

Cetane with tetra-ethyle lead

Question 6

Compression ratio for spark ignition engines usually varies between

Accepted Answer

6-13

Answer

4-6

Answer

10-18

Answer

14-25

Question 7

Four-stroke petrol engines as compared to two stroke petrol engines having same output rating and same compression ratio have

Accepted Answer

Higher thermal efficiency

Answer

Lower thermal efficiency

Answer

Higher specific fuel consumption

Answer

Higher specific output

Question 8

Compression ratio for compression ignition engines usually varies between

Accepted Answer

14-25

Answer

4-6

Answer

6-12

Answer

10-18

Question 9

The air requirement of a petrol engine during acceleration period in comparison to theoretically correct air required for complete combustion is

Accepted Answer

Less

Answer

More

Answer

Same

Answer

May be less or more depending upon engine capcity