Thermal Engineering 3

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Objective Questions and Answer: Thermal Engineering 3

Subject: Thermal Engineering 3

Part 3: Objective questions and answers of Thermal Engineering

 

Q1. If the temperature of intake air in internal combustion engine increases, then its efficiency will

a) Remain same

b) Decrease

c) Increase

d) None of the above

 

Q2. The thermal efficiency of a petrol engine is ______ as compared to diesel engine.

a) Same

b) Less

c) More

d) None of the above

 

Q3. In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as

a) Scavenging

b) Detonation

c) Supercharging

d) Polymerization

 

Q4. In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to

a) Prevent sparking across the gap between the points

b) Cause more rapid of the primary current, giving a higher voltage in the secondary circuit

c) Both (a) and (b)

d) None of the above

 

Q5. Supercharging is the process of supplying the intake air to the engine cylinder at a density ______ the density of the surrounding atmosphere.

a) Equal to

b) Less than

c) Greater than

d) None of the above

 

Q6. A diesel engine is ______ as compared to petrol engine, both running at rated load

a) Equally efficient

b) Less efficient

c) More efficient

d) None of the above

 

Q7. The firing order in I. C. Engine depends upon

a) Arrangement of the cylinders

b) Design of crankshaft

c) Number of cylinders

d) All of these

 

Q8. The spark ignition engines are governed by

a) Hit and miss governing

b) Qualitative governing

c) Quantitative governing

d) Combination of (b) and (c)

 

Q9. The air – fuel ratio of the petrol engine is controlled by

a) Carburetor

b) Injector

c) Governor

d) None of these

 

Q10. The loud pulsating noise heard within the cylinder of an internal combustion engine is known as

a) Detonation

b) Turbulence

c) Pre – ignition

d) Supercharging

 

Q11. Which of the following does not relate to a spark ignition engine ?

a) Ignition coil

b) Spark plug

c) Carburetor

d) Fuel injector

 

Q12. Which of the following does not relate to a compression ignition engine

a) Fuel pump

b) Fuel injector

c) Governor

d) Carburetor

 

Q13. The object of supercharging the engine is

a) To reduce mass of the engine per brake power

b) To reduce space occupied by the engine

c) To increase the power output of an engine when greater power is required

d) All of the above

 

Q14. The frictional power (F.P) is given by

a) F.P = B.P – I.P

b) F.P = I.P – B.P

c) F.P = B.P / I.P

d) F.P = I.P / B.P

 

Q15. The ratio of the work obtained at the crankshaft in a given time to the energy supplied during the same time is called

a) Mechanical efficiency

b) Overall efficiency

c) Indicated thermal efficiency

d) Volumetric efficiency

 

Q16. A compressed air may be used

a) In gas turbine plants

b) For operating pneumatic drills

c) In starting and supercharging of I.C engines

d) All of the above

 

Q17. The ratio of recharge pressure to the inlet pressure of air is called

a) Compression ratio

b) Expansion ratio

c) Compressor efficiency

d) Volumetric efficiency

 

Q18. The volume of air sucked by the compressor during its suction stroke is called

a) Free air delivery

b) Compressor capacity

c) Swept volume

d) None of these

 

Q19. The compressor capacity is defined as the

a) Actual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions

b) Volume of air delivered by the compressor

c) Volume of air sucked by the compressor during its suction stroke

d) None of the above

 

Q20. The ratio of work done per cycle to the stroke volume of the compressor is known as

a) Compressor capacity

b) Compression ratio

c) Compressor efficiency

d) Mean effective pressure

 

Part 3: Objective questions and answers of Thermal Engineering

 

Q1. Answer: b

Q2. Answer: b

Q3. Answer: a

Q4. Answer: c

Q5. Answer: c

Q6. Answer: c

Q7. Answer: d

Q8. Answer: b

Q9. Answer: a

Q10. Answer: a

Q11. Answer: d

Q12. Answer: d

Q13. Answer: d

Q14. Answer: b

Q15. Answer: b

Q16. Answer: d

Q17. Answer: a

Q18. Answer: c

Q19. Answer: b

Q20. Answer: d

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