Heat and Mass Transfer
According of Kirchhoff's law

Radiant heat is proportional to fourth power of absolute temperature
Emissive power depends on temperature
Emissive power and absorptivity are constant for all bodies
Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Film coefficient is defined as Inside diameter of tube

Film coefficient × Inside diameter Thermal conductivity
Equivalent thickness of film
Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity
Thermal conductivity Equivalent thickness of film Specific heat × Viscosity

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer,

The better insulation must be put inside
One should take into account the steam temperature before deciding as to which insulation is put where
One could place either insulation on either side
The better insulation must be put outside

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Conduction is a process of heat transfer

From one particle of the body to another by the actual motion of the heated particles
None of these
From a hot body to a cold body, in a straight line, without affecting the intervening medium
From one particle of the body to another without the actual motion of the particles

ANSWER DOWNLOAD EXAMIANS APP

Heat and Mass Transfer
Thermal conductivity of a material may be defined as the

Quantity of heat flowing in one second through one cm cube of material when opposite faces are maintained at a temperature difference of 1°C
Heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces
All of these
Quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Heat and Mass Transfer