Question: Leidenfrost point is a term concerned with the
[A].

condensation of the saturated vapor on a cold surface.

[B].

concentration of a corrosive solution by evaporation.

[C].

heat transfer between two highly viscous liquids.

[D].

boiling of a liquid on a hot surface.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Heat transfer in the laminar sublayer in case of a liquid flowing through a pipe, is mostly by
[A].

eddies current

[B].

conduction

[C].

convection

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.

Question: Electro-magnetic spectrum range, which is important for radiation varies from __________ microns.
[A].

1 to 100

[B].

0.5 to 50

[C].

10 to 100

[D].

100 to 1000

Answer: Option B

Explanation:

No answer description available for this question.

Question: Heat transfer rate per unit area is called
[A].

thermal conductivity

[B].

heat flux

[C].

heat transfer co-efficient

[D].

thermal diffusivity

Answer: Option B

Explanation:

No answer description available for this question.

Question: Kirchoff s law applies to __________ radiation.
[A].

total

[B].

monochromatic

[C].

both (a) & (b)

[D].

neither (a) nor (b)

Answer: Option C

Explanation:

No answer description available for this question.

Question: With increase in porosity, the thermal conductivity of a solid substance
[A].

increases

[B].

decreases

[C].

remains unchanged

[D].

may increase or decrease; depends on the solid

Answer: Option B

Explanation:

No answer description available for this question.

Question: Maximum heat transfer rate is achieved in __________ flow.
[A].

co-current

[B].

counter-current

[C].

turbulent

[D].

laminar

Answer: Option C

Explanation:

No answer description available for this question.

Question: In case of heat transfer by conduction in a hollow cylinder, __________ mean area is used to calculate the heat transfer rate.
[A].

geometric

[B].

arithmetic

[C].

logarithmic

[D].

either (a), (b) or (c)

Answer: Option C

Explanation:

No answer description available for this question.