250+ TOP MCQs on Petrol Engine Fuel Supply System – Supercharging and Answers

Automotive Engine Auxiliary Systems Multiple Choice Questions on “Petrol Engine Fuel Supply System – Supercharging”.

1. What is the another name of supercharger?
a) Pump
b) Diffuser
c) Cooler
d) Compressor
Answer: d
Clarification: A Supercharger is an air compressor that increases the pressure of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen.

2. Which of the mentioned below is not a driving mechanism of a supercharger?
a) Exhaust gas
b) Belt
c) Gear
d) Chain
Answer: a
Clarification:Power for the supercharger can be provided mechanically using a belt, gear, shaft, or chain connected to the engine’s crankshaft.

3. For a super charger, the drive is obtained by which part of the engine?
a) Cam
b) Connecting rod
c) Exhaust manifold
d) Crankshaft
Answer: d
Clarification: Power for the supercharger can be provided mechanically using a belt, gear, shaft, or chain connected to the engine’s crankshaft. Whereas, turbocharger is driven by exhaust gas.

4. Which are the types of supercharger based on method of gas transfer?
a) Positive displacement and dynamic compressors
b) Positive displacement and negative displacement
c) Dynamic compressors and Static compressors
d) Negative displacement and Static compressors
Answer: a
Clarification: There are two main types of superchargers defined according to the method of gas transfer, they are positive displacement and dynamic compressors.

5. Which supercharger delivers an almost constant level pressure increase at all engine RPM?
a) Dynamic compressor
b) Negative displacement
c) Static compressor
d) Positive displacement
Answer: d
Clarification: Positive displacement supercharger deliver an almost constant level pressure increase at all engine RPM and Dynamic compressor does not deliver pressure at low speeds; above the threshold, speed pressure increases exponentially.

6. Which supercharger doesn’t deliver pressure at low speeds?
a) Dynamic compressor
b) Negative displacement
c) Static compressor
d) Positive displacement
Answer: a
Clarification: Positive displacement supercharger deliver an almost constant level pressure increase at all engine RPM; above the threshold, speed pressure increases exponentially in a compressor.

7. On what basis positive displacement superchargers are usually rated?
a) Capacity per revolution
b) Parts per million
c) Displacement of engine
d) Size of exhaust manifold
Answer: a
Clarification: Positive displacement superchargers are usually rated by their capacity per revolution. In this case of the roots blower, the GMC rating pattern is typical.

8. Which of the mentioned below is the disadvantage of supercharger?
a) More volume of air
b) Increase in temperature
c) Higher density
d) Cold air
Answer: b
Clarification: One disadvantage of supercharging is that compressing the air increases its temperature. Extreme temperature will cause detonation of the fuel-air mixture.

9. Internal compression devices usually use varying compression ratio.
a) True
b) False
Answer: b
Clarification: Internal compression devices usually use a fixed internal compression ratio. When the boosted pressure is equal to the compression pressure of the supercharger, the backflow is zero.

10. When the boosted pressure is equal to the compression pressure of the supercharger, what is the value of the backflow?
a) 10
b) 4
c) 2
d) 0
Answer: d
Clarification: When the boosted pressure is equal to the compression pressure of the supercharger, the backflow is zero. Since the backflow is zero, further the air is forcefully injected and higher power is obtained.

11. Which are the types of dynamic compressors?
a) Centrifugal and centripetal
b) Single-stage and multi-stage axial flow
c) Centripetal and single-stage axial flow
d) Centrifugal and multi-stage axial flow
Answer: d
Clarification: Dynamic compressors rely on accelerating the air to high speed. Major types of dynamic compressors are centrifugal and multi-stage axial flow.

12. What happens to the engine if there is an increase in the temperature of the air+fuel mixture?
a) Lower vibration
b) Higher torque
c) High efficiency
d) Detonation
Answer: d
Clarification: One of the disadvantages of supercharging is that compressing the air increases its temperature. Extreme temperature will cause detonation of the fuel-air mixture.

13. In two-stroke engines, what is required to purge exhaust gasses?
a) Lighter piston
b) Lubrication
c) Oil
d) Scavenging
Answer: d
Clarification: In two-stroke engines, scavenging is required to purge exhaust gasses, as well as charge the cylinders for the next power stroke. In small engines, this requirement is commonly met by using the crankcase as a blower.