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As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient

CHEMICAL ENGINEERING, Heat Transfer /
Question: As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient
[A].

continues to increase.

[B].

continues to decrease.

[C].

goes through a minimum.

[D].

goes through a maximum.

Answer: Option C

Explanation:

No answer description available for this question.

As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient Read More »

CHEMICAL ENGINEERING, Heat Transfer

For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then

CHEMICAL ENGINEERING, Heat Transfer /
Question: For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then
[A].

hf = hd

[B].

hf > hd

[C].

hf < hd

[D].

hf could be greater or smaller than hd

Answer: Option C

Explanation:

No answer description available for this question.

For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then Read More »

CHEMICAL ENGINEERING, Heat Transfer

At steady state the temperature variation in a plane wall, made of two different solids I & II is shown below :The thermal conductivity of material I

CHEMICAL ENGINEERING, Heat Transfer /
Question: At steady state the temperature variation in a plane wall, made of two different solids I & II is shown below :The thermal conductivity of material I
[A].

is smaller than that of II.

[B].

is greater than that of II.

[C].

is equal to that of II.

[D].

can be greater than or smaller than that of II.

Answer: Option A

Explanation:

No answer description available for this question.

At steady state the temperature variation in a plane wall, made of two different solids I & II is shown below :The thermal conductivity of material I Read More »

CHEMICAL ENGINEERING, Heat Transfer

For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area

CHEMICAL ENGINEERING, Heat Transfer /
Question: For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area
[A].

increases

[B].

decreases

[C].

remains constant

[D].

passes through a maxima

Answer: Option D

Explanation:

No answer description available for this question.

For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area Read More »

CHEMICAL ENGINEERING, Heat Transfer

In thermal radiation for a black body (where, ε is emissivity and α is absorptivity)

CHEMICAL ENGINEERING, Heat Transfer /
Question: In thermal radiation for a black body (where, ε is emissivity and α is absorptivity)
[A].

α = 1; ε ≠ 1

[B].

α ≠ 1, ε = 1

[C].

α ≠ 1, ε ≠ 1

[D].

α = 1; ε = 1

Answer: Option D

Explanation:

No answer description available for this question.

In thermal radiation for a black body (where, ε is emissivity and α is absorptivity) Read More »

CHEMICAL ENGINEERING, Heat Transfer

A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2.K. The Biot number is

CHEMICAL ENGINEERING, Heat Transfer /
Question: A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2.K. The Biot number is
[A].

5.6

[B].

0.025

[C].

3.5

[D].

0.0035

Answer: Option B

Explanation:

No answer description available for this question.

A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2.K. The Biot number is Read More »

CHEMICAL ENGINEERING, Heat Transfer

In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be

CHEMICAL ENGINEERING, Heat Transfer /
Question: In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be
[A].

less than 45°C

[B].

more than 45°C

[C].

equal to 45°C

[D].

initially decreases and remains constant thereafter.

Answer: Option B

Explanation:

No answer description available for this question.

In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining the same, the temperature of the exit liquid will be Read More »

CHEMICAL ENGINEERING, Heat Transfer

Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be

CHEMICAL ENGINEERING, Heat Transfer /
Question: Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be
[A].

0.35

[B].

0.45

[C].

0.55

[D].

0.85

Answer: Option B

Explanation:

No answer description available for this question.

Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be Read More »

CHEMICAL ENGINEERING, Heat Transfer

An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is

CHEMICAL ENGINEERING, Heat Transfer /
Question: An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is
[A].

4000

[B].

9000

[C].

4600

[D].

3000

Answer: Option A

Explanation:

No answer description available for this question.

An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is Read More »

CHEMICAL ENGINEERING, Heat Transfer