This set of IC Engines Multiple Choice Questions & Answers (MCQs) focuses on “Delay Period”.
1. ___________ is the time immediately following injection of the fuel during which the ignition process is being initiated and the pressure does not rise beyond the value it would have due to compression of air.
a) Knocking
b) Delay period
c) Startability
d) None of the mentioned
View Answer
Explanation: Delay period is defined as the time immediately following injection of the fuel during which the ignition process is being initiated and the pressure does not rise beyond the value it would have due to compression of air.
2. The ___________ extends for about 13º, movement of the crank.
a) knocking
b) delay period
c) start ability
d) none of the mentioned
View Answer
Explanation: None.
3. The time for which delay period occurs decreases with ___________ in engine speed.
a) increases
b) decreases
c) unpredictable
d) none of the mentioned
View Answer
Explanation: None.
4. Delay period serves a useful purpose in that it allows the fuel jet to penetrate well into the combustion space.
a) True
b) False
View Answer
Explanation: None.
5. If the delay is too short the amount of fuel available for the simultaneous explosion is too great and the resulting pressure rise is too rapid.
a) True
b) False
View Answer
Explanation: No, in fact, if the delay is too long the amount of fuel available for a simultaneous explosion is too great and the resulting pressure rise is too rapid.
6. The delay period depends upon temperature and pressure in the cylinder at the time of injection.
a) True
b) False
View Answer
Explanation: None.
7. The delay period ___________ with load.
a) increases
b) decreases
c) unpredictable
d) none of the mentioned
View Answer
Explanation: Delay period is directly proportional to load, so the delay period increases with load.
8. The delay period depends upon the nature of the fuel mixture strength.
a) True
b) False
View Answer
Explanation: None.
9. Higher cetane number means a ___________ delay period and smoother engine operation.
a) higher
b) lower
c) normal
d) none of the mentioned
View Answer
Explanation: None.
10. Increase in compression ratio ___________ delay period.
a) increases
b) reduces
c) unpredictable
d) none of the mentioned
View Answer
Explanation: Compression ratio is indirectly proportional to delay period, so an increase in compression ratio reduces delay period.
11. At constant speed, delay period is proportional to the delay angle.
a) True
b) False
View Answer
Explanation: None.
12. A pre-combustion chamber gives a shorter delay compared to an open type of combustion chamber.
a) True
b) False
View Answer
Explanation: None.
Sanfoundry Global Education & Learning Series – IC Engine.
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