Heat Transfer MCQs

Question 1

Baffles are provided in heat exchangers to increase the

Accepted Answer

Heat transfer co-efficient

Answer

Fouling factor

Answer

Heat transfer area

Answer

Heat transfer rate

Question 2

What is the geometric mean of two heat transfer areas A1 and A2?

Accepted Answer

$$\sqrt {{{	ext{A}}_1} \cdot {{	ext{A}}_2}} $$

Answer

$$\sqrt {{{	ext{A}}_1} + {{	ext{A}}_2}} $$

Answer

$$\frac{1}{2}\sqrt {{{	ext{A}}_1} \cdot {{	ext{A}}_2}} $$

Answer

$$2\sqrt {{{	ext{A}}_1} \cdot {{	ext{A}}_2}} $$

Question 3

If the thermal conductivity of a wall material is independent of temperature, the steady state temperature distribution in the very large thin plane wall having steady, uniform surface tempeature follows __________ law.

Accepted Answer

Parabolic

Answer

Hyperbolic

Answer

Linear

Answer

Logarithmic

Question 4

In a single effect evaporator, the economy is

Accepted Answer

< 1

Answer

1

Answer

> 1

Answer

None of these

Question 5

Fruit juice (a heat sensitive material) can be concentrated in a __________ evaporator.

Accepted Answer

Falling film

Answer

Long tube

Answer

High pressure

Answer

None of these

Question 6

Film condensation is promoted on a/an __________ surface.

Accepted Answer

Clean & smooth

Answer

Oily

Answer

Coated

Answer

Dirty

Question 7

Dropwise condensation is promoted on a/an __________ surface.

Accepted Answer

Oily

Answer

Glazed

Answer

Coated

Answer

Smooth

Question 8

In a backward feed multiple effect evaporator

Accepted Answer

Feed flows from low pressure to high pressure

Answer

Feed is introduced in the first effect

Answer

No pumps are required between successive effects

Answer

None of these

Question 9

Which type of heat exchanger is preferred for heavy heat loads?

Accepted Answer

Series and parallel set of shell and tube

Answer

Double pipe

Answer

Plate fine

Answer

None of these