Heat Transfer

Question: For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it
[A].

decreases the pressure drop.

[B].

decreases the outlet temperature of cooling medium.

[C].

increases the overall heat transfer coefficient.

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Heat transfer by radiation between two bodies at T1 & T2 and in an ambient temperature of Ta°C depends on
[A].

T1 – T2

[B].

T1 – Ta

[C].

T2 – Ta

[D].

none of these

Answer: Option D

Explanation:

No answer description available for this question.

Question: In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to __________ the velocity head.
[A].

twice

[B].

four times

[C].

square root of

[D].

square of

Answer: Option B

Explanation:

No answer description available for this question.

Question: A BTU/hr.ft.2 °F is equal to
[A].

1 kcal/hr. m2°C.

[B].

4.88 kcal/hr. m.2°C.

[C].

1 kcal/hr. m2.°K.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Out of the following four assumptions used in the derivation of the equation for LMTD , which one is subject to the largest deviation in practice ?
[A].

Constant overall heat transfer co-efficient.

[B].

Constant rate of fluid flow.

[C].

Constant specific heat.

[D].

No partial phase change in the system.

Answer: Option B

Explanation:

No answer description available for this question.

Question: LMTD for counterflow and prallel flow heat exchanger will be the same, when the
[A].

cold fluid is heated to a certain temperature by condensing steam (isothermal fluid).

[B].

outlent temperature of both the hot and cold fluid are same.

[C].

outlet temperature of hot fluid is less than the outlet temperature of the cold fluid.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.

Question: In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid.
[A].

equal to

[B].

more than

[C].

less than

[D].

either more or less than (depending upon the fluid)

Answer: Option A

Explanation:

No answer description available for this question.

Question: An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a
[A].

boiler

[B].

heat exchanger

[C].

recuperator

[D].

regenerator

Answer: Option B

Explanation:

No answer description available for this question.

Question: Boiling point elevation of an ideal solution
[A].

increases rapidly with temperature rise.

[B].

decreases rapidly with temperature rise

[C].

in independent of pressure.

[D].

both (b) and (c).

Answer: Option A

Explanation:

No answer description available for this question.

Question: In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred
[A].

through a metallic wall.

[B].

by direct contact of hot flue gas with air.

[C].

by heating an intermediate material (like chequor bricks) and then heating the air from this hot material.

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.