CHEMICAL ENGINEERING

Question: Heat transfer efficiency leading of energy conservation in a heat exchanger can be achieved by
[A].

keeping the heat transfer surface clean.

[B].

enhancing the fluid pumping rate.

[C].

increasing the tube length.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by This is valid for the value of NRe equal to
[A].

< 2100

[B].

2100-4000

[C].

> 4000

[D].

> 10000

Answer: Option D

Explanation:

No answer description available for this question.

Question: __________ equation relates the thermal conductivity of a solid to its temperature.
[A].

Antonie

[B].

Kopp’s

[C].

Lee’s

[D].

Kistyakowski

Answer: Option C

Explanation:

No answer description available for this question.

Question: For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone.
[A].

extremely low

[B].

low

[C].

high

[D].

no

Answer: Option C

Explanation:

No answer description available for this question.

Question: Nusselt number is the ratio of the temperature gradient at the wall to
[A].

temperature difference

[B].

heat flux

[C].

that across the entire pipe

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Minimum recommended baffle spacing in a shell and tube heat exchanger is about (where, D = shell diameter)
[A].

0.2 D

[B].

0.5 D

[C].

0.66 D

[D].

0.80 D

Answer: Option A

Explanation:

No answer description available for this question.

Question: Baffles are provided in heat exchangers to increase the
[A].

fouling factor

[B].

heat transfer area

[C].

heat transfer co-efficient

[D].

heat transfer rate

Answer: Option C

Explanation:

No answer description available for this question.

Question: If heat transfer rate varies with the time, it is termed as
[A].

forced convection

[B].

steady state conduction

[C].

monochromatic radiation

[D].

none of these

Answer: Option D

Explanation:

No answer description available for this question.

Question: A hot body will radiate heat most rapidly, if its surface is
[A].

white & rough

[B].

black & rough

[C].

white & polished

[D].

black & polished

Answer: Option B

Explanation:

No answer description available for this question.

Question: A black body when hot, emits heat radiation of __________ wavelengths.
[A].

small

[B].

large

[C].

all

[D].

one fixed

Answer: Option C

Explanation:

No answer description available for this question.