Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

The type of rotary compressor used in gas turbines, is of

A. centrifugal type
B. axial flow type
C. radial flow type
D. none of these
Answer» C. radial flow type
Discussion
2.

The inlet pressure is always __________ the discharge pressure.

A. equal to
B. less than
C. more than
D. -
Answer» C. more than
Discussion
3.

The clearance volume in the compressor is kept minimum because it effects on volumetric efficiency.

A. Correct
B. Incorrect
C. -
D. -
Answer» B. Incorrect
Discussion
4.

The ratio of workdone 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
Answer» E.
Discussion
5.

For a two stage reciprocating compressor, compression from p 1 to p 3 is with perfect intercooling and no pressure losses. If compression in both the cylinders follows the same polytropic process and the atmospheric pressure is p a , then the intermediate pressure p 2 is given by

A. p 2 = ( p 1 + p 3 )/2
B. p 2 = p 1 . p 3
C. P 2 = P a x p 3 / p 1
D. p 2 = p a p 3 / p 1
Answer» C. P 2 = P a x p 3 / p 1
Discussion
6.

Intercooling in multi-stage compressors is done

A. to cool the air during compression
B. to cool the air at delivery
C. to enable compression in two stages
D. to minimise the work of compression
Answer» E.
Discussion
7.

The capacity of a compressor is expressed in

A. kg/m 2
B. kg/m 3
C. m 3 /min
D. m 3 /kg
Answer» D. m 3 /kg
Discussion
8.

The maximum delivery pressure in a rotary air compressor is

A. 10 bar
B. 20 bar
C. 30 bar
D. 50 bar
Answer» B. 20 bar
Discussion
9.

The increase in pressure in a vane blower takes place first due to compression and then due to back flow of air.

A. Correct
B. Incorrect
C. -
D. -
Answer» B. Incorrect
Discussion
10.

In a single acting reciprocating compressor, the suction, compression and delivery of air takes place in __________ of the piston.

A. one stroke
B. two strokes
C. three strokes
D. four strokes
Answer» C. three strokes
Discussion
11.

An open cycle gas turbine works on the same cycle as that of a closed cycle gas turbine.

A. Yes
B. No
C. -
D. -
Answer» B. No
Discussion
12.

In a jet propulsion

A. the propulsive matter is ejected from within the propelled body
B. the propulsive matter is caused to flow around the propelled body
C. its functioning does not depend upon presence of air
D. none of the above
Answer» C. its functioning does not depend upon presence of air
Discussion
13.

The total heat rejected in a reciprocating air compressor is equal to the sum of the heat rejected during polytropic compression per kg of air and heat rejected in the intercooler per kg of air.

A. True
B. False
C. -
D. -
Answer» B. False
Discussion
14.

The stagnation pressure rise in a centrifugal compressor takes place

A. in the diffuser only
B. in the impeller only
C. in the diffuser and impeller
D. in the inlet guide vanes only
Answer» D. in the inlet guide vanes only
Discussion
15.

The rotary compressors are suitable for large discharge of air at low pressure.

A. True
B. False
C. -
D. -
Answer» B. False
Discussion
16.

The maximum temperature in a gas turbine is

A. 200°C
B. 500°C
C. 700°C
D. 1000°C
Answer» D. 1000°C
Discussion
17.

The volumetric efficiency for reciprocating air compressors is about

A. 10 to 40%
B. 40 to 60%
C. 60 to 70%
D. 70 to 90%
Answer» E.
Discussion
18.

A rocket works with maximum overall efficiency when air-craft velocity is __________ the jet velocity.

A. equal to
B. one-half
C. double
D. -
Answer» C. double
Discussion
19.

In a four stage compressor, if the pressure at the first and third stage are 1 bar and 16 bar, then the delivery pressure at the fourth stage will be

A. 1 bar
B. 16 bar
C. 64 bar
D. 256 bar
Answer» D. 256 bar
Discussion