Applied Thermodynamics (3161910) MCQs

MCQs of Part-I Reciprocating Compressors

Showing 31 to 40 out of 66 Questions
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31.

Which of the following statement is correct?

(a)

The ratio of the discharge pressure to the inlet pressure of air is called compressor efficiency
(b)

The compression ratio for the compressor is always greater than unity
(c)

The compressor capacity is the ratio of work-done per cycle to the stroke volume
(d)

During isothermal compression of air, the work-done in a compressor is maximum
Answer:

Option (b)

32.

In a single-stage, single-acting reciprocating air compressor, without clearance, the work done on the air during isentropic compression is __________ the heat required to raise the temperature of air from T1 to T2 at a constant pressure.

(a)

equal to
(b)

less than
(c)

greater than
(d)

none of the mentioned
Answer:

Option (a)

33.

A large clearance volume in a reciprocating compressor results in

(a)

reduced volume flow rate
(b)

increased volume flow rate
(c)

lower suction pressure
(d)

lower delivery pressure
Answer:

Option (a)

34.

The reason for volumetric efficiency of reciprocating compressor being less than 100 percent is

(a)

pressure drop across the valves
(b)

superheating in compressor
(c)

clearance volume and leakages
(d)

all of these
Answer:

Option (d)

35.

The ratio of the volume of free air delivery per stroke to the swept volume of the piston is known as

(a)

compressor efficiency
(b)

volumetric efficiency
(c)

isothermal efficiency
(d)

mechanical efficiency
Answer:

Option (b)

36.

Cylinder clearance in a compressor should be

(a)

as large as possible
(b)

as small as possible
(c)

about 50% of swept volume
(d)

about 100% of swept volume
Answer:

Option (b)

37.

The performance of air compressor at higher altitude will be_________as compared to that at sea level.

(a)

same
(b)

lower
(c)

higher
(d)

none of the mentioned
Answer:

Option (b)

38.

A compressor at high altitudes will require __________ power.

(a)

same
(b)

less
(c)

more
(d)

all of the mentioned
Answer:

Option (b)

39.

Volumetric efficiency is

(a)

the ratio of stroke volume to clearance volume
(b)

the ratio of the air actually delivered to the amount of piston displacement
(c)

reciprocal of compression ratio
(d)

index of compressor performance
Answer:

Option (b)

40.

The volumetric efficiency of a compressor

(a)

constant with decrease in compression ratio
(b)

decreases with decrease in compression ratio
(c)

increases with increase in compression ratio
(d)

decreases with increase in compression ratio
Answer:

Option (d)

Showing 31 to 40 out of 66 Questions
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