250+ TOP MCQs on Engine Performance Parameters and Answers

IC Engines Multiple Choice Questions on “Engine Performance Parameters”.

1. The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called ___________
a) net efficiency
b) efficiency ratio
c) relative efficiency
d) overall efficiency
Answer: c
Clarification: Relative efficiency is defined as the ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency.

2. Compression ratio of I.C. engine is ___________
a) the ratio of volumes of air in cylinder before compression stroke and after compression stroke
b) volume displaced by piston per stroke and clearance volume in cylinder
c) ratio of pressure after compression and before compression
d) swept volume/cylinder volume
Answer: a
Clarification: None.

3. The air standard efficiency of an otto cycle compared to a diesel cycle for the given compression ratio is?
a) same
b) less
c) more
d) more or less depending on power rating
Answer: c
Clarification: None.

4. The calorific value of gaseous fuels is expressed in terms of ___________
a) Kcal
b) Kcal/kg
c) Kcal/m²
d) Kcal/m³
Answer: d
Clarification: None.

5. Indicated power of a 4-stroke engine is equal to ___________
a) pLAN
b) 2pLAN
c) pLAN/2
d) 4pLAN
Answer: c
Clarification: Indicated power of a 4-stroke engine is equal to pLAN/2.
where p = mean effective pressure,
L = stroke
A = area of piston and
N = rpm of engine.

6. If the intake air temperature of I.C. engine increases its efficiency will ___________
a) increase
b) decrease
c) remain same
d) none of the mentioned
Answer: b
Clarification: None.

7. All heat engines utilize ___________
a) low heat value of oil
b) high heat value of oil
c) net calorific value of oil
d) calorific value of fuel
Answer: a
Clarification: None.

8. An engine indicator is used to determine the following ___________
a) speed
b) temperature
c) volume of cylinder
d) m.e.p and I.H.P
Answer: d
Clarification: None.

9. Fuel oil consumption guarantees for I.C. engine are usually based on ___________
a) low heat value of oil
b) high heat value of oil
c) net calorific value of oil
d) calorific value of fuel
Answer: b
Clarification: None.

10. The thermal efficiency of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will ___________
a) increase
b) decrease
c) be independent
d) none of the mentioned
Answer: b
Clarification: None.