Fluid Mechanics

Question: A stream tube is that, which has __________ cross-section entirely bounded by stream lines.
[A].

a circular

[B].

any convenient

[C].

a small

[D].

a large

Answer: Option B

Explanation:

No answer description available for this question.

Question: I.D. of 1/4″ schedule 40 pipe is 0.364″. I.D. of a 1/2″ schedule 40 pipe would be __________ inch
[A].

4.728

[B].

0.5

[C].

0.622

[D].

0.474

Answer: Option C

Explanation:

No answer description available for this question.

Question: Nominal size of the discharge pipe of a pump is usually __________ the nominal size of the inlet pipe.
[A].

smaller than

[B].

larger than

[C].

same as

[D].

twice

Answer: Option A

Explanation:

No answer description available for this question.

Question: Actual lift of a pump is always less than the theoretical lift and is limited by the
[A].

specific gravity & temperature of the liquid.

[B].

leakage & pressure decreasing at higher elevations.

[C].

frictional resistance through pipes, fittings & passages.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Delivery of insufficient quantity of liquid by a pump may be caused by
[A].

air leak in the inlet

[B].

low rpm

[C].

too high a lift

[D].

all (a), (b) and (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: A pump operating under specific conditions delivers insufficient quantity of liquid. This may be set right by
[A].

decreasing the size of the inlet pipe.

[B].

increasing the size of the inlet pipe.

[C].

lowering the pump position.

[D].

both (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: A rectangular surface 3′ x 4′, has the lower 3 edge horizontal and 6′ below a free oil surface (sp. gr. 0.8). The surface inclination is 300 with the horizontal. The force on one side of the surface is(where, y = specific weight of water)
[A].

39.6y

[B].

48y

[C].

49.2y

[D].

58y

Answer: Option B

Explanation:

No answer description available for this question.

Question: Centrifugal pump can’t be used to pump
[A].

molten sodium (used as a coolant in Fast Breeder Reactor).

[B].

moderately viscous vegetable oil used in soap industry.

[C].

thick molten soap at 80°C.

[D].

none of the above.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Multistage centrifugal pumps are generally used for
[A].

high head.

[B].

low head but high discharge.

[C].

highly viscous liquid.

[D].

slurries of high solid concentration.

Answer: Option A

Explanation:

No answer description available for this question.

Question: For flow through a venturi at a particular discharge, the correct relationships among velocities at point X, Y and Z would be
[A].

V1 < V2 < V3

[B].

V2 > V1 and V2 > V3

[C].

V1 > V2 > V3

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.