Fluid Mechanics

Question: Net positive suction head (NPSH) of a centrifugal pump must be
[A].

greater than the vapour pressure of the liquid.

[B].

less than the vapour pressure of the liquid.

[C].

equal to the vapour pressure of the liquid.

[D].

less than barometric pressure.

Answer: Option A

Explanation:

No answer description available for this question.

Question: For the same flow rate of a fluid, the pressure drop is the least for
[A].

venturimeter

[B].

orificemeter

[C].

flow-nozzle

[D].

Δp is same for all

Answer: Option A

Explanation:

No answer description available for this question.

Question: A liquid is pumped at the rate of 600 litres using 1000 rpm. If the rpm is changed to 1100, the liquid pumped is __________ litres.
[A].

600

[B].

660

[C].

1.1

[D].

60

Answer: Option B

Explanation:

No answer description available for this question.

Question: A fluid is pumped at the rate of 10 lb/sec to a height of 55 ft. The horse power required is __________ hp.
[A].

1

[B].

10/55

[C].

5.5

[D].

1/55

Answer: Option A

Explanation:

No answer description available for this question.

Question: For very low pressure and high discharge rate, the compressor used is a/an __________ compressor.
[A].

axial

[B].

reciprocating

[C].

rotary

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: A mercury (specific gravity = 13.6) manometer connected across an orificemeter fitted in a pipe shows a manometer reading of 2 cms. If the manometer liquid is changed to carbon tetrachloride (specific gravity = 1.6), then for the same flow rate of water the new manometer reading will be __________ cms.
[A].

17

[B].

42

[C].

84

[D].

1.8

Answer: Option A

Explanation:

No answer description available for this question.

Question: For pumping slurry, one can use a __________ pump.
[A].

reciprocating

[B].

diaphargm

[C].

centrifugal

[D].

pneumatic

Answer: Option B

Explanation:

No answer description available for this question.

Question: In turbulent flow, the
[A].

fluid particles move in an orderly manner.

[B].

momentum transfer is on molecular scale only.

[C].

shear stress is caused more effectively by cohesion than momentum transfer.

[D].

shear stresses are generally larger than in a similar laminar flow.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Multistage compressors are used in industry, because they
[A].

reduce the cost of compressor.

[B].

reduce the size requirement,

[C].

resemble closely to isothermal compression.

[D].

are easy to control.

Answer: Option C

Explanation:

No answer description available for this question.

Question: A fluidis moving at critical flow condition (NRe = 2100) through a pipe of dia 3 cms. Velocity of flow is __________ cm/sec.
[A].

7

[B].

700

[C].

7000

[D].

630

Answer: Option A

Explanation:

No answer description available for this question.