Centrifugal Compressors - Mechanical Engineering (MCQ) questions and answers

1)   The mass flow rate of air compressed in axial flow compressor is _____________centrifugal compressor.

a. lower than
b. higher than
c. same as
d. unpredictable
Answer  Explanation 

ANSWER: higher than

Explanation:
No explanation is available for this question!


2)   Which of the following is NOT a type of rotary compressor?

a. Positive displacement type of compressor
b. Steady flow compressor
c. Both a. and b.
d. None of the above
Answer  Explanation 

ANSWER: None of the above

Explanation:
No explanation is available for this question!


3)   Which compressors are suitable for large volume flow rates of above 1200 m3/min

a. Centrifugal compressors
b. Axial flow compressors
c. Both a. and b.
d. None of the above
Answer  Explanation 

ANSWER: Axial flow compressors

Explanation:
No explanation is available for this question!


4)   The function of _________ is to convert high kinetic energy of gases into pressure energy.

a. impeller
b. diffuser
c. casing
d. None of the above
Answer  Explanation 

ANSWER: diffuser

Explanation:
No explanation is available for this question!


5)   How is the variation of air velocity while passing through impeller followed by diffuser in centrifugal compressor?

a. Air velocity goes no increasing in impeller followed by diffuser
b. Air velocity goes no decreasing in impeller followed by diffuser
c. Air velocity increases in impeller and then decreases in diffuser
d. Air velocity decreases in impeller and then increases in diffuser
Answer  Explanation 

ANSWER: Air velocity increases in impeller and then decreases in diffuser

Explanation:
No explanation is available for this question!


6)   Angular momentum of gas in the free vortex of vaneless diffuser ___________.

a. increases
b. decreases
c. remains constant
d. becomes unpredictable
Answer  Explanation 

ANSWER: remains constant

Explanation:
No explanation is available for this question!


7)   Vaneless diffusers are suitable for ___________.

a. only low pressure rise
b. only high pressure rise
c. both low as well as high pressure rise

Answer  Explanation 

ANSWER: only low pressure rise

Explanation:
No explanation is available for this question!


8)   The diffuser blades are kept ______ the number of impeller blades .

a. 1/10 th of
b. 1/3 rd of
c. 10 times
d. 3 times
Answer  Explanation 

ANSWER: 1/3 rd of

Explanation:
No explanation is available for this question!


9)   The ratio of actual whirl velocity to the ideal whirl velocity in the centrifugal compressor is called as _________.

a. velocity factor
b. slip factor
c. work factor
d. none of the above
Answer  Explanation 

ANSWER: slip factor

Explanation:
No explanation is available for this question!


10)   What is the ratio of isentropic work to Euler work in an centrifugal compressor called?

a. Work coefficient
b. Velocity coefficient
c. Pressure coefficient
d. Flow coefficient
Answer  Explanation 

ANSWER: Pressure coefficient

Explanation:
No explanation is available for this question!