# Axial Flow Compressors - Mechanical Engineering (MCQ) questions and answers

1)   What is the formula for blade loading coefficient (Ψ) for an axial flow compressor?

Where,
W = Workdone
Cf = Axial flow velocity
Cb = Blade velocity

a. Ψ = W / (Cf)2
b. Ψ = (Cf)2 / W
c. Ψ = W / (Cb)2
d. Ψ = (Cb)2 / W
 Answer  Explanation ANSWER: Ψ = W / (Cb)2 Explanation: No explanation is available for this question!

2)   A pair of fixed blade and rotor blade in axial flow compressor is called as _________.

a. step
b. pair
c. stage
d. state
 Answer  Explanation ANSWER: stage Explanation: No explanation is available for this question!

3)   An axial flow compressors have _______.

a. a drum type rotor
b. a disc type rotor
c. a drum type rotor or a disc type rotor
d. none of the above
 Answer  Explanation ANSWER: a drum type rotor or a disc type rotor Explanation: No explanation is available for this question!

4)   ________ blades are attached to the rotor or spindle.

a. Fixed
b. Moving
c. Both fixed and moving
d. None of the above
 Answer  Explanation ANSWER: Moving Explanation: No explanation is available for this question!

5)   The basic principle of operation of axial flow compressor is _______that of the centrifugal compressor.

a. same as
b. totally different than

 Answer  Explanation ANSWER: same as Explanation: No explanation is available for this question!

6)   The blade passages in a compressor are ________

a. converging
b. diverging
c. constant
d. unpredictable
 Answer  Explanation ANSWER: diverging Explanation: No explanation is available for this question!

7)   ___________ can be defined as the ratio of the pressure rise in rotor blades to the pressure rise in stages in an axial flow compressor.

a. Degree of pressure
b. Degree of reaction
c. Pressure ratio
d. Reaction ratio
 Answer  Explanation ANSWER: Degree of reaction Explanation: No explanation is available for this question!

8)   What is the ratio of the actual work absorbed by an axial flow compressor to the theoretical work called?

a. Work input factor
b. Workdone factor
c. Both a. and b.
d. None of the above
 Answer  Explanation ANSWER: Both a. and b. Explanation: No explanation is available for this question!

9)   What is the effect of increasing number of stages in axial flow compressor on the mean work input factor (Ψw)?

a. Mean work input factor (Ψw) decreases
b. Mean work input factor (Ψw) increases
c. Mean work input factor (Ψw) remains constant
d. Unpredictable
 Answer  Explanation ANSWER: Mean work input factor (Ψw) decreases Explanation: No explanation is available for this question!

10)   What is the effect of increasing flow coefficient (Φ) in an axial flow compressor on blade loading coefficient (Ψ)?

a. Blade loading coefficient (Ψ) increases
b. Blade loading coefficient (Ψ) decreases
c. Blade loading coefficient (Ψ) remains constant
d. Unpredictable
 Answer  Explanation ANSWER: Blade loading coefficient (Ψ) decreases Explanation: No explanation is available for this question!