Steam

Solid ice

Melting ice

Water

B. Solid ice

Direct mixing of hot and cold fluids

A complete separation between hot and cold fluids

Flow of hot and cold fluids alternately over a surface

Generation of heat again and again

Thermometer

Thermistor

Thermocouple

None of these

I.C. engine

Air preheaters

Heating of building in winter

None of the above

Zeroth law of thermodynamics

First law of thermodynamics

Second law of thermodynamics

Kirchhoff's law

Higher

Lower

Same

Depends on the area of heat exchanger

Irregular surfaces

Nonuniform temperature surfaces

One dimensional cases only

Two dimensional cases only

k/h₀

2k/h₀

h₀/k

h₀/2k

Iron

Lead

Concrete

Wood

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.

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.

Blast furnace

Heating of building

Cooling of parts in furnace

Heat received by a person from fireplace

Kirchhoff's law

Stefan's law

Wines law

Planck's law

The better insulation must be put inside

The better insulation must be put outside

One could place either insulation on either side

One should take into account the steam temperature before deciding as to which insulation is put where

Conduction

Convection

Radiation

Conduction and convection

Convection

Radiation

Conduction

Both convection and conduction

Glass

Water

Plastic

Air

Directly proportional to the surface area of the body

Directly proportional to the temperature difference on the two faces of the body

Dependent upon the material of the body

All of the above

J/m² sec

J/m °K sec

W/m °K

Option (B) and (C) above

Absolute temperature

Square of temperature

Fourth power of absolute temperature

Fourth power of temperature

Conduction

Convection

Radiation

Conduction and convection

Reynold's number

Grashoff's number

Reynold's number, Grashoff's number

Prandtl number, Grashoff's number

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.

m²/hr

m²/hr °C

kcal/m² hr

kcal/m. hr °C

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

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

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

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

Their atoms collide frequently

Their atoms are relatively far apart

They contain free electrons

They have high density

Steam

Solid ice

Melting ice

Water

Directly proportional to thermal conductivity

Inversely proportional to density of substance

Inversely proportional to specific heat

All of the above

Reflected

Refracted

Transmitted

Absorbed

25 mm

40 mm

160 mm

800 mm

Solids

Liquids

Gases

None of these