## Internal Combustion Engine Questions and Answers Part-1

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

Explanation: 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

Explanation: The ratio of volumes of air in cylinder before compression stroke and after compression stroke

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

Explanation: more

4. The calorific value of gaseous fuels is expressed in terms of ___________
a) Kcal
b) Kcal/kg
c) Kcal/m2
d) Kcal/m3

Explanation: Kcal/m3

5. Indicated power of a 4-stroke engine is equal to __________ .
a) pLAN
b) 2pLAN
c) pLAN/2
d) 4pLAN

Explanation: 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

Explanation: If the intake air temperature of I.C. engine increases its efficiency will decrease

7. All heat engines utilize ___________
a) low heat value of oil
b) high heat value of oil
c) net heat value of oil
d) calorific value of fuel

Explanation: low heat value of oil

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

Explanation: m.e.p and I.H.P

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 heat value of oil
d) calorific value of fuel