Engineering Questions with Answers - Multiple Choice Questions
Steam Turbines MCQ’s – Centrifugal Compressor
1 - Question
Centrifugal compressors are also known as ____________
a) turbo compressors
b) radial compressors
c) turbo & radial compressors
d) none of the mentioned
View Answer
Answer: b
Explanation: Centrifugal compressors sometimes called as radial compressors.
2 - Question
In idealized turbo machinery, pressure rise is done by adding _______
a) Temperature
b) Mass
c) Kinetic energy
d) None of the mentioned
View Answer
Answer: c
Explanation: In idealized turbo machinery the pressure rise is done by adding kinetic energy.
3 - Question
The pressure rise in impeller is _________ the rise in diffuser.
a) equal to
b) greater than
c) equal to or greater than
d) none of the mentioned
View Answer
Answer: d
Explanation: Not in all cases pressure rise in diffuser equals to pressure rise in impeller in some cases pressure rise in impeller will be more than that of diffuser.
4 - Question
In centrifugal compressor velocity of flow leaving the impeller is equals to _______ in many cases.
a) Speed of sound
b) Double the speed of sound
c) Triple the speed of sound
d) None of the mentioned
View Answer
Answer: a
Explanation: Initially the flow enters straightly into the impeller and the impeller pushes the flow inwards to spin faster and finally when the flow is leaving impeller it has almost speed of sound.
5 - Question
________ are used as stationary compressors in steam turbines.
a) Moving vanes
b) Guide vanes
c) Moving & Guide vanes
d) None of the mentioned
View Answer
Answer: b
Explanation: Guide vanes are used as stationary compressors where guide vanes reduce the velocity and according to Bernoulli’s theorem when velocity is reduced its pressure is increased.
6 - Question
________________ has large change in inlet to exit radius when compared to centrifugal compressors.
a) Axial compressors
b) Axial & Centrifugal compressors
c) Centrifugal compressors
d) None of the mentioned
View Answer
Answer: c
Explanation: Centrifugal compressors has large change in inlet to exit temperature when compared to axial compressor.
7 - Question
The first part in both centrifugal compressor and axial compressor are similar.
a) True
b) False
View Answer
Answer: a
Explanation: The first in both centrifugal compressor and axial compressor are similar.
8 - Question
Centrifugal compressor __________ the energy by increasing the radius where as centrifugal fan decreases the energy.
a) increases
b) decreases
c) both follow the same
d) none of the mentioned
View Answer
Answer: b
Explanation: Both centrifugal compressor and centrifugal fan are similar as both increases the energy by reducing the radius.
9 - Question
Centrifugal compressors increases the density of fluid more than ________
a) 1%
b) 3%
c) 5%
d) 7%
View Answer
Answer: c
Explanation: Centrifugal compressors increases the density of fluid more than 5 %.
10 - Question
Centrifugal fan has relative fluid velocities ______
a) Mach number more than 0.3
b) Mach number less than 0.1
c) Mach number less than 0.3
d) Mach number more than 0.5
View Answer
Answer: c
Explanation: Centrifugal fans often operate at fluid velocities less than mach number 0.3.