Question: Log mean temperature difference (LMTD) cannot be used, if
[A].

heat transfer co-efficient over the entire heat exchanger is not constant.

[B].

there exists an unsteady state.

[C].

the heat capacity is not constant and there is a phase change.

[D].

none of these.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Dietus-Boelter equation cannot be used for molten metals mainly due to its very low
[A].

Prandtl number

[B].

Grashoff number

[C].

thermal conductivity

[D].

viscosity

Answer: Option A

Explanation:

No answer description available for this question.

Question: Multiple effect evaporation accounts for
[A].

steam economy

[B].

lower operating costs

[C].

investment economy

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: In forced circulation, the heating element is injected
[A].

internally

[B].

externally

[C].

both (a) and (a)

[D].

neither (a) nor (b)

Answer: Option A

Explanation:

No answer description available for this question.

Question: An ejector is used to
[A].

increase pressure

[B].

increase temperature

[C].

remove condensate

[D].

none of these

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used
[A].

in low range of temperature differences.

[B].

in high range of temperature differences.

[C].

because of its low cost.

[D].

to prevent corrosion of the tube bundles.

Answer: Option B

Explanation:

No answer description available for this question.

Question: With the increase of temperature, the Col-burn jH factor
[A].

increases.

[B].

decreases.

[C].

remains unchanged.

[D].

may increase or decrease ; depending on temperature.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Multiple effect evaporators ar used to
[A].

increase the steam economy & decrease the capacity.

[B].

increase the steam economy & the capacity.

[C].

decrease the steam economy & the capacity.

[D].

decrease the steam economy & increase the capacity.

Answer: Option B

Explanation:

No answer description available for this question.