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.

Question: In case of a shell and tube heat exchanger, the minimum and maximum baffle spacing is respectively (where, D = inside diameter of the shell)
[A].

D/5 and D

[B].

D/2 and 2 D

[C].

D/4 and 2 D

[D].

D and 2 D

Answer: Option A

Explanation:

No answer description available for this question.

Question: Open pan evaporators are preferred to be used, when the solution to be concentrated is
[A].

scaling

[B].

highly viscous

[C].

corrosive

[D].

salty

Answer: Option B

Explanation:

No answer description available for this question.

Question: Overall thermal resistance for conductive heat transfer through a series of flat resistances is equal to the
[A].

maximum resistance in the series.

[B].

sum of all resistances.

[C].

average of all resistances.

[D].

minimum resistance presents in the series.

Answer: Option B

Explanation:

No answer description available for this question.

Question: LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is
[A].

0

[B].

1

[C].

>1

[D].

<1

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a shell and tube heat exchanger, the shell side fluid velocity can not be changed by changing the
[A].

tube layout

[B].

tube diameter

[C].

tube pitch

[D].

no. of baffles

Answer: Option B

Explanation:

No answer description available for this question.