Hydraulic Machines

Question: Manometric head, in case of a centrifugal pump, is equal to
[A].

Suction lift + Loss of head in suction pipe due to friction + Delivery lift + Loss of head in delivery pipe due to friction + Velocity head in the delivery pipe

[B].

Workdone per kN of water – Losses within the impeller

[C].

Energy per kN at outlet of impeller – Energy per kN at inlet of impeller

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: In the casing of a centrifugal pump, the kinetic energy of the water is converted into pressure energy before the water leaves the casing.
[A].

True

[B].

False

Answer: Option A

Explanation:

No answer description available for this question.

Question: Which of the following statement is wrong ?
[A].

The reaction turbines are used for low head and high discharge.

[B].

The angle of taper on draft tube is less than 8°.

[C].

An impulse turbine is generally fitted slightly above the tail race.

[D].

A Francis turbine is an impulse turbine.

Answer: Option D

Explanation:

No answer description available for this question.

Question: The cavitation in reaction turbines is avoided, to a great extent by
[A].

installing the turbine below the tail race level

[B].

using stainless steel runner of the turbine

[C].

providing highly polished blades to the runner

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The cavitation in a hydraulic machine
[A].

causes noise and vibration of various parts

[B].

reduces the discharge of a turbine

[C].

causes sudden drop in power output and efficiency

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The cavitation in a hydraulic machine is mainly due to
[A].

low velocity

[B].

high velocity

[C].

low pressure

[D].

high pressure

Answer: Option C

Explanation:

No answer description available for this question.

Question: A Pelton wheel working under a constant head and discharge, has maximum efficiency when the speed ratio is
[A].

0.26

[B].

0.36

[C].

0, 46

[D].

0.56

Answer: Option C

Explanation:

No answer description available for this question.

Question: A draft tube is used with impulse turbines.
[A].

Yes

[B].

No

Answer: Option B

Explanation:

No answer description available for this question.

Question: A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used ?
[A].

Pelton wheel with one nozzle

[B].

Pelton wheel with two or more nozzles

[C].

Kaplan turbine

[D].

Francis turbine

Answer: Option A

Explanation:

No answer description available for this question.

Question: For 450 m head of water, __________ shallbeused.
[A].

Pelton wheel

[B].

Kaplan turbine

[C].

Francis turbine

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.