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Free download in PDF Turbomachines Multiple Choice Questions and Answers for competitive exams. These short objective type questions with answers are very important for competitive exams. These short solved questions or quizzes are provided by Gkseries.
(1)
What is the relation between Velocity Coefficient (Cc) and Nozzle efficiency (ηn)?
[A]
Cc = (1/2) (ηn)
[B]
Cc = √(ηn)
[C]
Cc = (ηn)2
[D]
Cc = (ηn)3
(2)
The ratio of actual mass flow rate (ṁa) to ideal mass flow rate (ṁi) is called as________
[A]
nozzle coefficient
[B]
coefficient of nozzle friction
[C]
coefficient of discharge
[D]
coefficient of mass
Answer: coefficient of discharge
(3)
The blade speed ratio of impulse turbine is given as ___________
[A]
(Blade velocity) / (Steam velocity at inlet)
[B]
(Blade velocity) / (Steam velocity at exit)
[C]
(Steam velocity at inlet) / (Blade velocity)
[D]
(Steam velocity at exit) / (Blade velocity)
Answer: (Blade velocity) / (Steam velocity at inlet)
(4)
Discharge capacity of the reciprocating pump is __________ that of the centrifugal pump.
[A]
higher than
[B]
lower than
[C]
same as
[D]
unpredictable
(5)
Which pump is more suitable for an application where very high pressure is required to be developed at moderate discharge?
[A]
Reciprocating pump
[B]
Centrifugal pump
[C]
Turbine
[D]
None of the above
Answer: Reciprocating pump
(6)
The process of filling the liquid into the suction pipe and pump casing upto the level of delivery valve is called as _________.
[A]
filling
[B]
pumping
[C]
priming
[D]
leveling
(7)
The volute pumps and vortex volute pumps are __________ pumps with _________ shaft.
[A]
multistage, horizontal
[B]
multistage, vertical
[C]
single stage, horizontal
[D]
single stage, vertical
Answer: single stage, horizontal
(8)
Which of the following centrifugal pumps has higher specific speed than the others?
[A]
Axial flow
[B]
Radial flow
[C]
Mixed flow
[D]
All have same specific speed
(9)
Angular momentum of gas in the free vortex of vaneless diffuser ___________.
[A]
increases
[B]
decreases
[C]
remains constant
[D]
becomes unpredictable
(10)
Vaneless diffusers are suitable for ___________.
[A]
only low pressure rise
[B]
only high pressure rise
[C]
both low as well as high pressure rise
[D]
None
Answer: only low pressure rise
(11)
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
(12)
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
(13)
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: Pressure coefficient
(14)
___________ 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: Degree of reaction
(15)
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
(16)
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: Mean work input factor (Ψw) decreases
(17)
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: Blade loading coefficient (Ψ) decreases
(18)
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
(19)
In reaction turbine work is done_______________.
[A]
totally due to change in kinetic energy of jet
[B]
totally due to change in pressure head
[C]
mostly due to change in pressure head and small amount of work is due to change in kinetic energy
[D]
mostly due to change in kinetic energy and small amount of work is due to change in pressure head
Answer: mostly due to change in pressure head and small amount of work is due to change in kinetic energy
(20)
In which type of turbine, the runner needs to be run full of water?
[A]
Impulse turbine
[B]
Reaction turbine
[C]
Both a. and b.
[D]
None of the above
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