Chemical Engineering

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.

Question: Creeping flow around a sphere is defined, when particle Reynolds number is
[A].

< 2100

[B].

< 0.1

[C].

> 2.5

[D].

< 500

Answer: Option B

Explanation:

No answer description available for this question.

Question: Equivalent length of a pipe fitting is
[A].

dependent on Reynolds number.

[B].

independent of Reynolds number.

[C].

dependent on the length of the pipe.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.

Question: At a constant speed of the centrifugal pump . it __________ the impeller diameter.
[A].

capacity varies directly with

[B].

head varies as the square of

[C].

horsepower varies as the cube of

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: With a constant diameter impeller of a centrifugal pump
[A].

its capacity varies directly as the square of speed.

[B].

head varies as the square of speed.

[C].

horsepower input varies as the square of speed.

[D].

head varies as the speed.

Answer: Option B

Explanation:

No answer description available for this question.

Question: A centrifugal pump designed to pump water is employed to pump a more viscous oil. In the later case, the pump
[A].

develops a lower head.

[B].

capacity is reduced.

[C].

requires more power.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Mass velocity is independent of temperature & pressure, when the flow is
[A].

unsteady through unchanged cross-section.

[B].

steady through changing cross-section.

[C].

steady and the cross-section is unchanged.

[D].

unsteady and the cross-section is changed.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Cavitation in a centrifugal pump results from
[A].

high discharge pressure

[B].

low barometric pressure

[C].

high discharge velocity

[D].

high discharge rate

Answer: Option B

Explanation:

No answer description available for this question.