Internal Combustion Engines MCQs

Question 1

Injection lag is

Accepted Answer

Time before actual fuel injection and the pump pluger starts to pump fuey

Answer

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

Answer

Time corresponding to actual injection and top dead centre

Answer

Time corresponding to actual ignition and top dead centre

Question 2

Ignition quality of diesel-fuel oil is ex, pressed by an index called

Accepted Answer

Cetane number

Answer

Octane number

Answer

Calorific value

Answer

Carbon content

Question 3

Carbon residue in diesel oil should not be more than

Accepted Answer

0.10%

Answer

1%

Answer

0.50%

Answer

0.01%

Question 4

The most popular firing order in case of four cylinder in-line I.C. engine is

Accepted Answer

1-3-4-2

Answer

1-2-3-4

Answer

1-4-2-3

Answer

1-2-4-3

Question 5

The compression ratio of motor cars is

Accepted Answer

7

Answer

5

Answer

10

Answer

13

Question 6

The specific gravity of diesel oil is

Accepted Answer

0.85

Answer

1

Answer

0.7

Answer

0.5

Question 7

Freezing temperature of petrol is usually

Accepted Answer

Less than -30°C

Answer

0°C

Answer

-10°C

Answer

10°C

Question 8

Pick up the correct statement. Detonation can be controlled by

Accepted Answer

Retarding the spark timing

Answer

Varying compression ratio

Answer

Using lean mixture

Answer

Reducing the r.p.m.

Question 9

The efficiency of I.C. engines normally is of the order of

Accepted Answer

30-35%

Answer

15-20%

Answer

20-25%

Answer

25-30%