CHEMICAL ENGINEERING

Question: In the low Reynolds number region, the drag force on a sphere is proportional to
[A].

V

[B].

V2

[C].

V4

[D].

V0.5

Answer: Option A

Explanation:

No answer description available for this question.

Question: For the laminar flow of a fluid in a circular pipe of radius R, the Hagen-Poisseule equation predicts the volumetric flow rate to be proportional to
[A].

R

[B].

R2

[C].

R4

[D].

R0.5

Answer: Option C

Explanation:

No answer description available for this question.

Question: A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity
[A].

same as that of A.

[B].

one fourth as that of A.

[C].

twice as that of A.

[D].

four times as that of A.

Answer: Option B

Explanation:

No answer description available for this question.

Question: For Laminar flow through a packed bed, the pressure drop is proportional to (Vs is the superficial liquid velocity and Dp is the particle diameter)
[A].

Vs/Dp2

[B].

Vs2/Dp2

[C].

Vs2/Dp3

[D].

Vs/Dp3

Answer: Option A

Explanation:

No answer description available for this question.

Question: In a fully turbulent flow (Re > 105) in a pipe of diameter ‘d’, for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is
[A].

d

[B].

d2

[C].

d2.5

[D].

d4

Answer: Option C

Explanation:

No answer description available for this question.

Question: A rotameter through which air at room temperature and atmospheric pressure is flowing gives a certain reading for a flow rate of 100 cc/sec. If helium (molecular weight 4) is used and rotameter shows the same reading, the flow rate (cc/sec) is
[A].

26

[B].

42

[C].

269

[D].

325

Answer: Option C

Explanation:

No answer description available for this question.

Question: In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes
[A].

less than atmospheric pressure.

[B].

more than liquid vapor pressure.

[C].

less than liquid vapor pressure.

[D].

more than atmospheric pressure.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is
[A].

90

[B].

60

[C].

45

[D].

30

Answer: Option B

Explanation:

No answer description available for this question.

Question: A bed consists of particles of density 2000 kg/m3. If the height of the bed is 1.5 metres and its porosity 0.6, the pressure drop required to fluidise the bed by air is
[A].

25.61 kPa

[B].

11.77 kPa

[C].

14.86 kPa

[D].

21.13 kPa

Answer: Option B

Explanation:

No answer description available for this question.

Question: A Pitot tube indicates 5 cm of water (manometer) when it is being used for measuring velocity of air. The velocity of air in m/sec is
[A].

5

[B].

14.1

[C].

56.22

[D].

28.2

Answer: Option D

Explanation:

No answer description available for this question.