Heat and Mass Transfer MCQs

Question 1

The most commonly used method for the design of duct size is the

Accepted Answer

Static regains method

Answer

Velocity reduction method

Answer

Equal friction method

Answer

Dual or double method

Question 2

The value of Prandtl number for air is about

Accepted Answer

0.7

Answer

0.1

Answer

0.3

Answer

1.7

Question 3

A steam pipe is to be insulated by two insulating materials put over each other. For best results

Accepted Answer

Better insulation should be put over pipe and better one over it

Answer

Inferior insulation should be put over pipe and better one over it

Answer

Both may be put in any order

Answer

Whether to put inferior OIL over pipe or the better one would depend on steam temperature

Question 4

Total heat is the heat required to

Accepted Answer

Convert water into steam and superheat it

Answer

Change vapour into liquid

Answer

Change liquid into vapour

Answer

Increase the temperature of a liquid or vapour

Question 5

Sensible heat is the heat required to

Accepted Answer

Increase the temperature of a liquid of vapour

Answer

Change vapour into liquid

Answer

Change liquid into vapour

Answer

Convert water into steam and superheat it

Question 6

When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by

Accepted Answer

Conduction

Answer

Convection

Answer

Radiation

Answer

Conduction and convection

Question 7

When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by

Accepted Answer

Radiation

Answer

Conduction

Answer

Convection

Answer

Conduction and convection

Question 8

The concept of overall coefficient of heat transfer is used in case of heat transfer by

Accepted Answer

Conduction and convection

Answer

Conduction

Answer

Convection

Answer

Radiation

Question 9

When heat is transferred by molecular collision, it is referred to as heat transfer by

Accepted Answer

Convection

Answer

Conduction

Answer

Radiation

Answer

Scattering