Iron

Lead

Concrete

Wood

B. Lead

Move actually

Do not move actually

Affect the intervening medium

Does not affect the intervening medium

0.45

0.55

0.40

0.75

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

Stanton number

Biot number

Peclet number

Grashoff number

Grey body

Brilliant white polished body

Red hot body

Black body

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

h₁ + h₂ + h₃

(h₁.h₂.h₃)1/3

1/h₁ + 1/h₂ + 1/h₃

None of these

Conduction

Convection

Radiation

None of these

Composition

Density

Porosity

All of the above

Directly proportional to the thermal conductivity

Inversely proportional to density of substance

Inversely proportional to specific heat

All of the above

k. A. (dT/dx)

k. A. (dx/dT)

k. (dT/dx)

k. (dx/dT)

Conduction

Convection

Radiation

Conduction and convection

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

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

Black body

Grey body

Opaque body

White body

Nature of the body

Temperature of the body

Type of surface of the body

All of these

Iron

Lead

Concrete

Wood

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.

Zeroth law of thermodynamics

First law of thermodynamic

Second law of the thermodynamics

Kirchoff's law

One

Two

Three

Four

High thickness of insulation

High vapour pressure

Less thermal conductivity insulator

A vapour seal

Conduction

Convection

Radiation

None of these

Increases

Decreases

Remain constant

May increase or decrease depending on temperature

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

_{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}

Universal gas constant

Kinematic viscosity

Thermal conductivity

Planck's constant

Reflected

Refracted

Transmitted

Absorbed

The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature

The wave length corresponding to the maximum energy is proportional to the absolute temperature

The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body

None of the above

Conduction

Convection

Radiation

Conduction and radiation combined

Melting of ice

Boiler furnaces

Condensation of steam in condenser

None of these