CHEMICAL ENGINEERING

Question: In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller.
[A].

speed of

[B].

diameter of

[C].

fluid velocity leaving

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: At high Reynolds number
[A].

inertial forces control and viscous forces are unimportant.

[B].

viscous forces predominate.

[C].

inertial forces are unimportant and viscous forces control.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the
[A].

back flow of fluid in the event of stoppage of pump.

[B].

discharge pressure.

[C].

flow of liquid during operation of the pump.

[D].

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

Answer: Option A

Explanation:

No answer description available for this question.

Question: Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, σ = surface tension of mercury)
[A].

d

[B].

1/d

[C].

σ

[D].

l/σ

Answer: Option C

Explanation:

No answer description available for this question.

Question: Dimension of surface tension is(where, F = force, L = length)
[A].

FL-1

[B].

F-1 . L

[C].

F.L-2

[D].

F-2 . L

Answer: Option A

Explanation:

No answer description available for this question.

Question: Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.)
[A].

d

[B].

d1/3

[C].

d2

[D].

d2/3

Answer: Option A

Explanation:

No answer description available for this question.

Question: Drag force on the float of a rotameter is(where Q = flow rate of the )
[A].

∝Q

[B].

∝Q

[C].

∝Q2

[D].

constant

Answer: Option D

Explanation:

No answer description available for this question.

Question: Fanning friction factor for laminar flow of fluid in a circular pipe is
[A].

not a function of the roughness of pipe wall.

[B].

inversely proportional to Reynolds number.

[C].

both (a) & (b).

[D].

neither (a) nor (b).

Answer: Option C

Explanation:

No answer description available for this question.

Question: At low Reynolds number
[A].

viscous forces are unimportant.

[B].

viscous forces control.

[C].

viscous forces control and inertial forces are unimportant.

[D].

gravity forces control.

Answer: Option C

Explanation:

No answer description available for this question.

Question: A pipe is defined as ‘hydraulically smooth’, if the friction factor
[A].

is not a function of Reynolds number.

[B].

for a given Reynolds number remains constant even on further smoothening of the pipe.

[C].

is zero irrespective of the Reynolds number.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.