Absorptivity of a body will be equal to its emissivity___________________?

Question: In a parallel flow heat exchanger, if the outlet temperature of hot and cold fluids are the same, then the log mean temperature difference (LMTD) is
[A].

minimum

[B].

maximum

[C].

zero

[D].

infinity

Answer: Option C

Explanation:

No answer description available for this question.

Question: Low thermal conductivity of heat insulating materials is due to its
[A].

dense structure.

[B].

high proportion of air space.

[C].

high specific heat.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: The average heat transfer co-efficient over the entire length of the plate (ha) and the local heat transfer co-efficient (hL), in case of heat transfer over a flat plate in lminar zone is related as
[A].

ha = 0.8hL

[B].

ha = 2hL

[C].

ha = hL

[D].

ha = 5hL

Answer: Option B

Explanation:

No answer description available for this question.

Question: With increase in temperature, the thermal conductivity of fresh lubricating oil
[A].

increases

[B].

decreases

[C].

remains unchanged

[D].

may increase or decrease; depends on its composition

Answer: Option B

Explanation:

No answer description available for this question.