Convection

Radiation

Conduction

Both convection and conduction

C. Conduction

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.

h = k/ ρS

h = ρS/k

h = S/ρk

h = kρ/S

Conduction

Convection

Radiation

Scattering

Black radiation

Full radiation

Total radiation

All of these

Better insulation should be put over pipe and better one over it

Inferior insulation should be put over pipe and better one over it

Both may be put in any order

Whether to put inferior OIL over pipe or the better one would depend on steam temperature

Emissivity

Transmissivity

Reflectivity

Intensity of radiation

Grashoff number

Nusselt number

Weber number

Prandtl number

Higher

Lower

Same

Depends on the area of heat exchanger

Thermal conductivity

Thermal diffusivity

Density

Dynamic viscosity

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

A dimensionless parameter

Function of temperature

Used as mathematical model

A physical property of the material

Electric heater

Steam condenser

Boiler

Refrigerator condenser coils

First law of thermodynamics

Newton's law of cooling

Newton's law of heating

Stefan's law

Aluminium

Steel

Brass

Copper

Moisture

Density

Temperature

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

Conduction

Free convection

Forced convection

Radiation

Directly proportional to thermal conductivity

Inversely proportional to density of substance

Inversely proportional to specific heat

All of the above

Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state

Both the fluids at inlet are in their hottest state

Both the fluids at exit are in their hottest state

One fluid is in hottest state and other in coldest state at inlet

One dimensional cases only

Two dimensional cases only

Three dimensional cases only

Regular surfaces having non-uniform temperature gradients

Stanton number

Biot number

Peclet number

Grashoff number

Cold body to hot body

Hot body to cold body

Smaller body to larger body

Larger body to smaller body

Density

Coefficient of viscosity

Gravitational force

All of these

2 TR

4 TR

8 TR

10 TR

Conduction

Convection

Radiation

Conduction and convection

Conduction

Convection

Radiation

Conduction and convection

Below which a gas does not obey gas laws

Above which a gas may explode

Below which a gas is always liquefied

Above which a gas will never liquefied

More than those for liquids

Less than those for liquids

More than those for solids

Dependent on the viscosity

Domestic refrigerators

Water coolers

Room air conditioners

All of these

Increases

Decreases

Remain constant

May increase or decrease depending on temperature