IC Engines
JKSSB Junior Engineer (Mechanical) · Metrology and Automobile Engineering · 21 practice questions with answers and explanations: 10 Easy, 11 Medium, 0 Hard.
Sample questions
Sample Easy question 1
A carburettor is used in:
- gas turbines
- petrol (spark ignition) engines
- steam engines
- diesel engines
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Answer: B. It prepares the air–fuel mixture for SI engines.
Sample Easy question 2
In a four-stroke engine, the number of crankshaft revolutions per power stroke is:
- Half
- One
- Two
- Four
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Answer: C. A four-stroke cycle takes two revolutions, with one power stroke per cycle.
Sample Easy question 3
The four strokes of a four-stroke engine in order are:
- Power, suction, compression, exhaust
- Compression, suction, exhaust, power
- Exhaust, power, compression, suction
- Suction, compression, power, exhaust
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Answer: D. Intake draws in the charge, compression squeezes it, combustion drives the piston, and exhaust clears the cylinder.
Sample Medium question 4
In a two-stroke engine, a power stroke occurs once every:
- Four revolutions
- Two revolutions
- Revolution of the crankshaft
- Half revolution
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Answer: C. A two-stroke cycle is completed in one revolution.
Sample Medium question 5
Turbocharging increases engine power by:
- Supplying air at higher pressure and density
- Increasing the compression ratio only
- Cooling the exhaust
- Reducing friction
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Answer: A. More air allows more fuel to be burnt per cycle.
Sample Medium question 6
Increasing the compression ratio of an Otto cycle engine generally:
- makes the cycle isothermal
- has no effect on efficiency
- decreases its thermal efficiency
- increases its thermal efficiency
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Answer: D. η = 1 − 1/r^(γ−1) rises with the compression ratio r (limited by knock).