250+ TOP MCQs on Diesel Engine Analysis and Answers

Power Plant Engineering Multiple Choice Questions on “Diesel Engine Analysis”.

1. A fuel of cetane number 40 has the same ignition quality as a mixture of __________
a) 40% alpha methyl napthalene and 60% cetane
b) 40% cetane and 60% alpha methyl napthalene
c) 40% petrol and 60% diesel
d) 40% diesel and 60% petrol
Answer: b
Clarification: A fuel of cetane number 40 has the same ignition quality as a mixture of 40% cetane and 60% alpha methyl naphthalene.

2. The control rods in the control system of nuclear reactors are used to __________
a) control fuel consumption
b) absorb excess neutrons
c) control temperature
d) all of the mentioned
Answer: b
Clarification: The function of control rods is to absorb the excess neutrons released during fission.

3. The pressure at the end of compression, in petrol engines, is approximately __________
a) 10 bar
b) 20 bar
c) 25 bar
d) 35 bar
Answer: a
Clarification: The pressure at the end of compression, in petrol engines, is approximately 10 bar.

4. If the speed of the engine is increased, the indicated power will __________
a) increase
b) decrease
c) remain same
d) none of the mentioned
Answer: a
Clarification: The speed of the engine & indicated power are inter related as they are directly proportional to each other, so if one increases, the other also increases & vice-versa.

5. Number of working strokes per min. for a two stroke cycle engine are __________ the speed of the engine in r.p.m.
a) equal to
b) one-half
c) four-times
d) twice
Answer: a
Clarification: Number of working strokes per min. for a two stroke cycle engine are equal to the speed of the engine in rpm.

6. Reflector in nuclear power plants __________ neutron leakage.
a) increases
b) decreases
c) has no effect
d) all of the mentioned
Answer: b
Clarification: Reflector in nuclear power plants decreases neutron leakage.

7. In order to eliminate knocking in compression ignition engines, there should be __________
a) high self-ignition temperature of fuel
b) late auto-ignition
c) short delay period
d) low compression ratio
Answer: c
Clarification: In order to eliminate knocking in compression ignition engines, there should be a shorter delay period.

8. Which of the following statement is correct?
a) Compression ratio for petrol engines varies from 6 to 10
b) Petrol engines work on Otto cycle
c) Higher compression ratio in diesel engines results in higher pressures
d) All of the mentioned
Answer: d
Clarification: All the mentioned statements are correct.

9. The injector nozzle of a compression ignition engine is required to inject fuel at a sufficiently high pressure in order to __________
a) inject fuel at a high velocity to facilitate atomisation
b) inject fuel in a chamber of high pressure at the end of compression stroke
c) ensure that penetration is not high
d) all of the mentioned
Answer: d
Clarification: The fuel injection is at a sufficiently higher pressure in order to inject fuel at a high velocity to facilitate atomisation, to inject fuel in a chamber of high pressure at the end of compression stroke & to ensure that penetration is not high.

10. The two reference fuels used for cetane rating are __________
a) cetane & iso-octane
b) cetane & normal heptane
c) cetane & alpha methyl naphthalene
d) cetane & tetra ethyl lead
Answer: c
Clarification: Cetane & alpha methyl naphthalene are the two reference fuels used for cetane rating.

11. In petrol engines, the delay period is of the order of __________
a) 0.001 sec
b) 0.002 sec
c) 0.003 sec
d) 0.004 sec
Answer: b
Clarification: The delay period in petrol engines is of the order of 0.002 sec.

12. How much voltage required to produce a spark across the gap, between the sparking points?
a) 2000-4000 volts
b) 4000-6000 volts
c) 6000-10000 volts
d) 10000-12000 volts
Answer: c
Clarification: The voltage required to produce a spark across the gap, between the sparking points is 6000-10000 Volts.

13. The scavenging efficiency of a tour stroke cycle diesel engine is __________
a) between 50-85%
b) between 95-100%
c) below 50%
d) between 85-95%
Answer: b
Clarification: The scavenging efficiency of a tour stroke cycle diesel engine is between 95-100%.

14. The specific fuel consumption per B.P. hour for a petrol engine is about __________
a) 0.2 kg
b) 0.25 kg
c) 0.3 kg
d) 0.35 kg
Answer: b
Clarification: The brake specific fuel consumption for a petrol engine is about 0.25 kg.

15. Which material is most commonly used for shielding?
a) Carbon
b) Concrete
c) Lead
d) All of the mentioned
Answer: c
Clarification: Lead is the material that is most commonly used for Shielding.