This set of IC Engines Multiple Choice Questions & Answers (MCQs) focuses on “Effects Of Supercharging”.
1. The knock limit is dependent upon ___________
a) the type of fuel used
b) mixture ratio
c) spark advance
d) all of the mentioned
View Answer
Explanation: The knock limit is dependent upon the following factors
i) the type of fuel used
ii) mixture ratio
iii) spark advance
iv) design feature of the engine.
2. For volatile petroleum fuels of high octane number, the knocking is reduced at _____________ mixture.
a) very rich
b) very lean
c) equal
d) none of the mentioned
View Answer
Explanation: It has been observed that for volatile petroleum fuels of high octane number, the knocking is reduced at very rich mixture and reduces pre-ignition at very lean mixture.
3. For volatile petroleum fuels of high octane number, pre-ignition is reduced at _____________ mixture.
a) very rich
b) very lean
c) equal
d) none of the mentioned
View Answer
Explanation: For volatile petroleum fuels of high octane number, pre-ignition is reduced at very lean mixture while the knocking is reduced at very rich mixture.
4. In alcoholic fuels the knock is reduced at _____________ mixtures.
a) rich
b) lean
c) equal
d) none of the mentioned
View Answer
Explanation: In alcoholic fuels the knock is reduced at rich mixtures because of the cooling effect of high latent heat of the fuel.
5. A slight ___________ in lean mixture makes the engine operation irregular and intermittent.
a) increase
b) reduction
c) heat
d) none of the mentioned
View Answer
Explanation: Very lean and very rich mixtures give non-knocking operations, and as a reason a slight reduction in lean mixture makes the engine operation irregular and intermittent.
6. The ignition timings and thermal load on the engine affect the knock limit of _____________ engine.
a) SI
b) CI
c) SI & CI
d) None of the mentioned
View Answer
Explanation: The ignition timings and thermal load on the engine affect the knock limit of SI engine while there is no such case in CI engine.
7. The pressure of supercharger used is ___________
a) 1.0 to 1.3 bar
b) 1.2 to 1.4 bar
c) 1.3 to 1.5 bar
d) none of the mentioned
View Answer
Explanation: In general, the supercharger pressure of 1.3 to 1.5 bar is used, which corresponds to about 30 to 50 percent supercharging.
8. In CI engine, the power developed by the turbocharger is sufficient to drive the compressor, and overcome mechanical friction.
a) True
b) False
View Answer
Explanation: In CI engine there is no use of superchargers, as in the case of SI engines, so the power from turbocharger is sufficient to drive the compressor and overcome mechanical friction.
9. Increase in pressure and temperature of the intake air increases significantly delay and rate of pressure.
a) True
b) False
View Answer
Explanation: Increase in pressure and temperature of the intake air reduces significantly delay and rate of pressure.
10. The speed range of turbocharger is from ___________
a) 10000 to 20000 r.p.m
b) 20000 to 30000 r.p.m
c) 30000 to 40000 r.p.m
d) none of the mentioned
View Answer
Explanation: The speed range of the turbocharger is from 20000 to 30000 r.p.m.
Sanfoundry Global Education & Learning Series – IC Engine.
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