Heat Transfer MCQs

Question 1

Peclet number (Pe) is given by

Accepted Answer

Pe = Re.Pr

Answer

$${	ext{Pe}} = \frac{{{	ext{Re}}}}{{{	ext{Pr}}}}$$

Answer

$${	ext{Pe}} = \frac{{{	ext{Pr}}}}{{{	ext{Re}}}}$$

Answer

Pe = Nu.Re

Question 2

Pick out the correct equation.

Accepted Answer

$${	ext{JH}} = \left( {{	ext{St}}} ight){\left( {{	ext{Pr}}} ight)^{\frac{2}{3}}} = \frac{{	ext{f}}}{2}$$

Answer

$${	ext{JH}} = \left( {{	ext{St}}} ight){\left( {{	ext{Pr}}} ight)^{\frac{1}{3}}} = \frac{{	ext{f}}}{2}$$

Answer

$${	ext{JH}} = {\left( {{	ext{St}}} ight)^{\frac{2}{3}}}\left( {{	ext{Pr}}} ight) = \frac{{	ext{f}}}{2}$$

Answer

$${	ext{JH}} = {\left( {{	ext{St}}} ight)^{\frac{1}{3}}}\left( {{	ext{Pr}}} ight) = \frac{{	ext{f}}}{2}$$

Question 3

Kirchoff s law applies to __________ radiation.

Accepted Answer

Both A & B

Answer

Total

Answer

Monochromatic

Answer

Neither A nor B

Question 4

The purpose of providing bleed points in the evaporator is to

Accepted Answer

Facilitate removal of non-condensable gases

Answer

Admit the feed

Answer

Remove the product

Answer

Create vacuum

Question 5

Which of the following is unimportant in forced convection?

Accepted Answer

Grashhoff number

Answer

Reynolds number

Answer

Prandtl number

Answer

None of these

Question 6

Duhring rule is important in solving problems on

Accepted Answer

Evaporation

Answer

Distillation

Answer

Crystallisation

Answer

Humidification

Question 7

Fourier's law of heat conduction applies to __________ surfaces.

Accepted Answer

Both A and B

Answer

Isothermal

Answer

Non-isothermal

Answer

Neither A and B

Question 8

Fourier's law applies to the heat transfer by

Accepted Answer

Conduction

Answer

Convection

Answer

Radiation

Answer

All of the above

Question 9

Prandtl number is the ratio of

Accepted Answer

Momentum diffusivity to thermal diffusivity

Answer

Momentum diffusivity to mass diffusivity

Answer

Thermal diffusivity to mass diffusivity

Answer

Thermal diffusivity to momentum diffusivity