Irregular surfaces

Nonuniform temperature surfaces

One dimensional cases only

Two dimensional cases only

C. One dimensional cases only

One

Two

Three

Four

Density

Coefficient of viscosity

Gravitational force

All of these

Thermometer

Thermistor

Thermocouple

None of these

Shorter wavelength

Longer wavelength

Remain same at all wavelengths

Wavelength has nothing to do with it

Black bodies

Polished bodies

All coloured bodies

All of the above

kcal/m²

kcal/hr °C

kcal/m² hr °C

kcal/m hr °C

2 TR

4 TR

8 TR

10 TR

Conduction

Convection

Radiation

Conduction and convection

_{1} r_{2} (T_{1} - T_{2})/ (r_{2} - r_{1})

_{1} r_{2} (T_{1} - T_{2})/ (r_{2} - r_{1})

_{1} r_{2} (T_{1} - T_{2})/ (r_{2} - r_{1})

_{1} r_{2} (T_{1} - T_{2})/ (r_{2} - r_{1})

Conduction

Convection

Radiation

Conduction and convection

Increases

Decreases

Remain constant

May increase or decrease depending on temperature

Convection

Radiation

Conduction

Both convection and conduction

More than those for liquids

Less than those for liquids

More than those for solids

Dependent on the viscosity

1 : 1

2 : 1

1 : 2

4 : 1

_{m} = (Δt_{1} - Δt_{2})/ log_{e} (Δt_{1}/Δt_{2})

_{m} = log_{e} (Δt_{1}/Δt_{2})/ (Δt_{1} - Δt_{2})

_{m} = t_{m} = (Δt_{1} - Δt_{2}) log_{e} (Δt_{1}/Δt_{2})

_{m} = log_{e} (Δt_{1} - Δt_{2})/ Δt_{1}/Δt_{2}

Electric heater

Steam condenser

Boiler

Refrigerator condenser coils

0.1

0.3

0.7

1.7

Moisture

Density

Temperature

All of the above

Absorptive power

Emissive power

Emissivity

None of these

Equivalent thickness of film

Thermal conductivity Equivalent thickness of film Specific heat × Viscosity

Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity

Film coefficient × Inside diameter Thermal conductivity

Nature of body

Temperature of body

Type of surface of body

All of the above

-1/3

-2/3

1

-1

Stanton number

Nusselt number

Biot number

Peclet number

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

None of these

Irregular surfaces

Nonuniform temperature surfaces

One dimensional cases only

Two dimensional cases only

Equal to

Directly proportional to

Inversely proportional to

None of these

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 time taken to attain the final temperature to be measured

The time taken to attain 50% of the value of initial temperature difference

The time taken to attain 63.2% of the value of initial temperature difference

Determined by the time taken to reach 100°C from 0°C

One dimensional cases only

Two dimensional cases only

Three dimensional cases only

Regular surfaces having non-uniform temperature gradients