Heat Transfer

Question: Intermittant tube cleaning is possible to be done in case of a __________ evaporator.
[A].

basket type

[B].

horizontal tube

[C].

calendria

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: A dephlegmator is a
[A].

total condenser

[B].

vacuum evaporator

[C].

partial condenser

[D].

double pipe heat exchanger

Answer: Option C

Explanation:

No answer description available for this question.

Question: For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally
[A].

decreases

[B].

increases

[C].

remains unchanged

[D].

increases exponentially

Answer: Option A

Explanation:

No answer description available for this question.

Question: Multiple effect evaporation is generally recommended, when the
[A].

large scale evaporation of liquor is needed.

[B].

corrosive liquids are to be concentrated.

[C].

fuel is cheaply available.

[D].

evaporation on small scale is to be done.

Answer: Option A

Explanation:

No answer description available for this question.

Question: jH factor for heat transfer is not a function of the __________ number.
[A].

Reynolds

[B].

Nusselt

[C].

Grashoff

[D].

both (b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: In case of heat flow by conduction for a cylindrical body with an internal heat source, the nature of temperature distribution is
[A].

linear

[B].

hyperbolic

[C].

parabolic

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re0.8 . Prn, is not valid, if the value of
[A].

n = 0.4 is used for heating.

[B].

n = 0.3 is used for cooling.

[C].

Reynolds number for the flow involved is > 10000.

[D].

Reynolds number for the flow involved is < 2100.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Arithmetic mean area can be used in heat transfer problem to calculate the heat flow by conduction through a cylinder which is
[A].

thin walled having the value of Ao Ai/< 2.

[B].

thick walled.

[C].

having the value of Ao/Ai > 2.

[D].

both (b) and (c).

Answer: Option A

Explanation:

No answer description available for this question.

Question: Analogy between mass and heat transfer is not applicable in case of
[A].

same velocity profile or equal eddy diffusivities.

[B].

thermal or pressure mass diffusion.

[C].

viscous heating or chemical reaction.

[D].

both (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Heat exchanger tubes are never made of
[A].

plain carbon steel

[B].

stainless steel

[C].

lead

[D].

copper

Answer: Option C

Explanation:

No answer description available for this question.