Thermal resistance

Thermal coefficient

Temperature gradient

Thermal conductivity

D. Thermal conductivity

S.H/(S.H + L.H)

(S.H + L.H) /S.H

(L.H - S.H)/S.H

S.H/(L.H - S.H)

Solids

Liquids

Gases

None of these

P = 0, x = 0 and a = 1

P= 1, T = 0 and a = 0

P = 0, x = 1 and a = 0

X = 0, a + p = 0 Where a = absorptivity, p = reflectivity, X = transmissivity.

The heat transfer in liquid and gases takes place according to convection.

The amount of heat flow through a body is dependent upon the material of the body.

The thermal conductivity of solid metals increases with rise in temperature

Logarithmic mean temperature difference is not equal to the arithmetic mean temperature difference.

Absolute temperature

T²

T⁵

T

Same

More

Less

Depends on other factors

2 TR

4 TR

8 TR

10 TR

Absolute temperature

Square of the absolute temperature

Cube of the absolute temperature

Fourth power of the absolute temperature

P = 0, x = 0 and a = 1

P=1, x = 0, and a = 0

P = 0, T= 1, and a = 0

X = 0, a + p = 1

A grey body is one which absorbs all radiations incident on it.

At thermal equilibrium, the emissivity and absorptivity are same.

The energy absorbed by a body to the total energy falling on it, is called emissivity.

A perfect body is one which is black in colour.

Added insulation will increase heat loss

Added insulation will decrease heat loss

Convective heat loss will be less than conductive heat loss

Heat flux will decrease

P = 0, x = 0 and a = 1

P=1, x = 0 and a = 0

P = 0, x = 1 and a = 0

X = 0, a + p = 1 Where a = absorptivity, p = reflectivity, X = transmissivity.

Equal to

Directly proportional to

Inversely proportional to

None of these

Directly proportional to the surface area

Directly proportional to the difference of temperatures between the two bodies

Either (A) or (B)

Both (A) and (B)

Blast furnace

Heating of building

Cooling of parts in furnace

Heat received by a person from fireplace

Grashoff number

Biot number

Stanton number

Prandtl number

Conduction

Convection

Radiation

None of these

I.C. engine

Air preheaters

Heating of building in winter

None of the above

Fourier equation

Stefan-Boltzmann equation

Newton Reichmann equation

Joseph-Stefan equation

Improve heat transfer

Provide support for tubes

Prevent stagnation of shell side fluid

All of these

Its temperature

Nature of the body

Kind and extent of its surface

All of the above

Energy transferred by convection to that by conduction

Kinematic viscosity to thermal diffusivity

Inertia force to viscous force

None of the above

Varies with temperature

Varies with wavelength of the incident ray

Is equal to its emissivity

Does not vary with temperature and. wavelength of the incident ray

kcal/m²

kcal/hr °C

kcal/m² hr °C

kcal/m hr °C

Higher

Lower

Same

Depends upon the shape of body

Radiators in automobile

Condensers and boilers in steam plants

Condensers and evaporators in refrigeration and air conditioning units

All of the above

1 : 1

2 : 1

1 : 2

4 : 1

Conduction

Convection

Radiation

Conduction and radiation combined

Grashoff number

Nusselt number

Weber number

Prandtl number

Temperature

Wave length

Physical nature

All of the above