250+ TOP MCQs on Supercharging and Answers

IC Engines Multiple Choice Questions on “Supercharging”.

1. Supercharging of S.I engines is employed only for aircraft and racing car engines.
a) True
b) False
Answer: a
Clarification: Supercharging requires when speed is taken into consideration so, supercharging of S.I engines is employed only for aircraft and racing car engines.

2. ____________ in supercharging pressure increases the tendency to detonate and pre-ignite.
a) Decrease
b) Increase
c) Unpredictable
d) None of the mentioned
Answer: a
Clarification: Detonation and pre-ignition are increased by an increase in supercharging pressure.

3. The supercharged petrol engines have a lower fuel consumption than naturally aspirated engines.
a) True
b) False
Answer: b
Clarification: Actually, supercharged petrol engines have a greater fuel consumption than naturally aspirated engines.

4. Increased intake pressure and temperature reduces ignition delay and decreases flame speed.
a) True
b) False
Answer: b
Clarification: In fact, increased intake pressure and temperature reduce ignition delay and increases flame speed.

5. The increased flame speeds make the petrol engine more sensitive to fuel-air ratio and engine cannot run on strong mixtures without knock.
a) True
b) False
Answer: b
Clarification: Actually, the increased flame speeds make the petrol engine more sensitive to fuel-air ratio and engine cannot run on weak mixtures without knock.

6. Rich mixtures are used to control detonation, which further increases the specific fuel consumption of the engine.
a) True
b) False
Answer: a
Clarification: None.

7. The ignition timings and thermal load on the engine affect the knock limit of CI engine.
a) True
b) False
Answer: b
Clarification: No, in fact the ignition timings and thermal load on the engine affect the knock limit of SI engine.

8. The ignition must be retarded at high intake pressure and temperature.
a) True
b) False
Answer: a
Clarification: None.

9. The power developed by the turbocharger is not sufficient to drive the compressor, and overcome its mechanical friction.
a) True
b) False
Answer: b
Clarification: In fact, the power developed by the turbocharger is sufficient to drive the compressor, and overcome its mechanical friction.

10. The loss in piston work due to the early opening of the exhaust valve is less than offset by better charging and scavenging of the engine.
a) True
b) False
Answer: b
Clarification: No, in fact, the loss in piston work due to the early opening of the exhaust valve is more than offset by better charging and scavenging of the engine.