MCQ ~ Internal Combustion Engines

1. In a four stroke engine, the working cycle is completed in

• One revolution of the crankshaft
• Two revolutions of the crankshaft
• Three revolutions of the crankshaft
• Four revolutions of the crankshaft

2. A two stroke cycle engine gives ............... the number of power strokes as compared to the four stroke cycle engine, at the same speed.

• Half
• Same
• Double
• Four times

3. The thermal efficiency of a two stroke cycle engine is .......... a four stroke cycle engine.

• Equal to
• Less than
• Greater than

4. The theoretically correct mixture of air and petrol is

• 10:1
• 15:1
• 20:1
• 25:1

5. The thermodynamic cycle on which the petrol engine works, is

• Otto cycle
• Joule cycle
• Rankine cycle
• Diesel cycle

6. A diesel engine has 

• One valve
• Two valves
• Three valves
• Four valves

7. If petrol is used in a diesel engine, then

• Low power will be produced
• Efficiency will be low
• Higher knocking will occur
• Black smoke will be produced

8. A petrol engine has compression ratio from

• 6 to 10
• 10 to 15
• 15 to 25
• 25 to 40

 9. The function of a distributor in a coil ignition system of I.C engines is

• To distribute the spark
• To distribute the power
• To distribute the current
• To time the spark

10. Supercharging ................ the power developed by the engine.

• Has no effect on
• Increases
• Decreases

11. A carburetor is used to supply  

• Petrol, air and lubricating oil
• Air and diesel
• Petrol and lubricating oil
• Petrol and air

12. A spark plug gap is kept from

• 0.3 to 0.7 mm
• 0.2 to 0.8 mm
• 0.4 to 0.9 mm
• 0.6 to 1.0 mm

13. The knocking tendency in spark ignition engines may be decreases by

• Controlling the air fuel mixture
• Controlling the ignition timing
• Reducing the compression ratio
• All of these

14. The violent sound pulsations within the cylinder of an I.C engine are due to

• Detonation
• Turbulence
• Pre-ignition
• None of these

15. Which of the  following does not relate to a spark ignition engine?

• Ignition coil
• Spark plug
• Distributor
• Fuel injector