Heat Transfer

Question: Heat produced when a steady state current, I passes through an electrical conductor having resistance, ‘R’ is
[A].

IR

[B].

I2R

[C].

IR2

[D].

I2R2

Answer: Option B

Explanation:

No answer description available for this question.

Question: With increase in the distance between the heat source and the object receiving the heat, the radiation heat transfer
[A].

decreases

[B].

increases

[C].

increases exponentially

[D].

remains unaffected

Answer: Option A

Explanation:

No answer description available for this question.

Question: __________ paint has the minimum absorption co-efficient.
[A].

Black

[B].

White lead

[C].

Grey

[D].

Light cream

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ paint has the maximum absorption coefficient.
[A].

Black

[B].

Yellow

[C].

White

[D].

Grey

Answer: Option A

Explanation:

No answer description available for this question.

Question: With increase in temperature, the total emissivity of conductors
[A].

increases

[B].

decreases

[C].

remains same

[D].

decreases linearly

Answer: Option A

Explanation:

No answer description available for this question.

Question: For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it
[A].

occupies smaller space.

[B].

is more economical.

[C].

is easy to operate and maintain.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: During crystallisation, formation of crystal can occur in __________ solution only.
[A].

saturated

[B].

supersaturated

[C].

undersaturated

[D].

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

Answer: Option B

Explanation:

No answer description available for this question.

Question: It is not preferable to use superheated steam in evaporators, because of its very
[A].

high temperature

[B].

high pressure

[C].

low film co-efficient

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Boiling point of a solution according to Duhring’s rule is a linear function of the __________ of water.
[A].

boiling point (at the same pressure)

[B].

viscosity

[C].

density

[D].

thermal conductivity

Answer: Option A

Explanation:

No answer description available for this question.

Question: Overall heat transfer co-efficient for cooling of hydrocarbons by water is about
[A].

50 -100 Kcal/hr.m2.°C

[B].

50 -100 W/m2 . °K

[C].

50 -100 BTU/hr. ft.2°F

[D].

1000 – 1500 BTU/hr. ft.2°F

Answer: Option C

Explanation:

No answer description available for this question.