For set 1 – Click here
Here are top 20 important MCQs of IC ENGINE. Read the questions carefully and try to answer all of them from your own.
Q1. Which of the following statement is wrong
(a) A four stroke cycle engine develops twice the power as that of a two stroke cycle engine
(b) For the same power developed, a four stroke cycle engine is lighter, less bulky and occupies less floor area
(c) The petrol engines are costly than diesel engines.
(d) all of the above.
Q2. In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as
(a) Polymerisation
(b) scavenging
(c) detonation
(d) supercharging
Q3. The scavenging efficiency of a four stroke cycle diesel engine is
(a) below 50%
(c) between 85 and 95%
(b) between 50 and 85%
(d) between 95 and 100%
Q4. In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to
(a) prevent sparking across the gap between the points
(b) cause more rapid break of the primary current, giving a higher voltage in the secondary circuit
(c) both (a) and (b)
(d) none of the above.
Q5. An ignition coil in the spark ignition engines supplies __ voltage to the spark plug
(a) high
(b) low
Q6. The voltage required to produce a spark across the gap, between the sparking points is
(a) 2000 to 4000 volts
(b) 4000 to 6000 volts
(c) 6000 to 10000 volts
(d) 10 000 to 12000 volts.
Q7. Supercharging is the process of supplying the intake air to the engine cylinder at a density the density of the surrounding atmosphere.
(a) equal to
(b) less than
(c) greater than
Q8. The increase in intake temperature of internal combustion engines will……… efficiency
(a) have no effect on
(b) increase
(c) decrease
Q9. The function of a distributor in a coil ignition system of 1.C. engines is
(a) to distribute spark
(b) to distribute power
(c) to distribute current
(d) to time the spark.
Q10. A supercharged engine as compared to an ordinary engine
(a) requires smaller foundation
(b) consumes less lubricating oil
(c) is lighter
(d) all of these.
Q11. Supercharging ___ the power developed by the engine
(a) has no effect on
(b) increases
(c) decreases
Q12. A carburettor is used to supply.
(a) petrol, air and lubricating oil
(b) petrol and lubricating oil
(c) air and diesel
(d) petrol and air
Q13. A diesel engine is ___ as compared to petrol engine, both running at rated load
(a) equally efficient
(b) less efficient depends upon
(c) more efficient
Q14. The firing order in an I.C. engine depends upon
(a) arrangement of the cylinders
(b) design of crankshaft
(c) number of cylinders
(d) all of these.
Q15. The compensating jet in a carburettor supplies almost constant amount of petrol at all speeds because the
(a) jet area is automatically varied depending on the suction
(b) the flow from the main jet is diverted to the compensatingjet with increase in speed
(c) the diameter of the jet is constant and the discharge coefficient is invariant
(d) flow is produced due to the static head in the float chamber.
Q16. Which of the following statement is correct
(a) Compression ratio for petrol engines varies from 6 to 10.
(b) Higher compression ratio in diesel engines results in higher pressures.
(c) Petrol engines work on Otto cycle.
(d) all of the above.
Q17. The spark ignition engines are governed by
(a) hit and miss governing
(b) quantitative governing
(c) qualitative governing
(d) combination of (b) and (c)
Q18. The compression ignition engines are governed by
(a) hit and miss governing
(b) quantitative governing
(c) qualitative governing
(d) combination of (b) and (c)
Q19. The air-fuel ratio of the petrol engine is controlled by
(a) carburettor
(b) injector
(c) governor
(d) none of these
Q20. The correct mixture strength (by weight) for petrol is about
(a) 14.6:1
(b) 18.5:1
(c) 20.4:1
(d) 22.6:1
That was the set 2 of top 20 important MCQs of IC ENGINE. Set 1 of IC ENGINE has been uploaded earlier. All read set 1 by clicking above link. This will help a lot for the competitive examinations. If you like this content then do share this with your well wishers. If you have any doubts regarding any mechanical engineering then let us know in comment section or contact us through email.