HEAT AND MASS TRANSFER QUIZ

160 mm

40 mm

800 mm

25 mm

Static regains method

Velocity reduction method

Dual or double method

Equal friction method

Same

More

Less

Depends on other factors

Forced convection

Convection

Radiation

Free convection

In convection, stirring of the fluid and cleaning the heating surface.

In radiation, increasing the temperature and reducing the emissivity.

All of these

In conduction, reduction in the thickness of the material and an increase in thermal conductivity.

Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body

Emissive power depends on temperature

Emissive power and absorptivity are constant for all bodies

Radiant heat is proportional to fourth power of absolute temperature

U/Cmin

U/A.Cmin

Cmin/U

U.Cmin

Scattering

Conduction

Radiation

Convection

The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body

The wave length corresponding to the maximum energy is proportional to the absolute temperature

The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature

None of these

0.75

0.4

0.45

0.55