Minimum energy

Maximum energy

Both (A) and (B)

None of these

B. Maximum energy

A dimensionless parameter

Function of temperature

Used as mathematical model

A physical property of the material

Cold water inlet and outlet

Hot medium inlet and outlet

Hot medium outlet and cold water inlet

Hot medium outlet and cold water outlet

h = k/ ρS

h = ρS/k

h = S/ρk

h = kρ/S

Zeroth law of thermodynamics

First law of thermodynamics

Second law of thermodynamics

Kirchhoff's law

Conduction

Convection

Radiation

None of these

Velocity reduction method

Equal friction method

Static regains method

Dual or double method

Directly proportional to thermal conductivity

Inversely proportional to density of substance

Inversely proportional to specific heat

All of the above

Increases

Decreases

Remain constant

May increase or decrease depending on temperature

Solids

Liquids

Gases

None of these

Liquids

Energy

Temperature

Entropy

Hr (time)

Sq. m (area)

°C (temperature)

K.cal (heat)

1 : 1

2 : 1

1 : 2

4 : 1

Thermal coefficient

Thermal resistance

Thermal conductivity

None of these

k₁ k₂

(k₁ + k₂)

(k₁ + k₂)/ k₁ k₂

2 k₁ k₂/ (k₁ + k₂)

Thermal resistance

Thermal coefficient

Temperature gradient

Thermal conductivity

Thermal conductivity to the equivalent thickness of the film of fluid

Temperature drop through the films of fluids to the thickness of film of fluids

Thickness of film of fluid to the thermal conductivity

Thickness of film of fluid to the temperature drop through the films of fluids

Free electrons

Atoms colliding frequency

Low density

Porous body

6

9

27

81

Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁)

Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)]

Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁)

Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁)

Watt/cm² °K

Watt/cm4 °K

Watt²/cm °K⁴

Watt/cm² °K⁴

Iron

Lead

Concrete

Wood

Radiators in automobile

Condensers and boilers in steam plants

Condensers and evaporators in refrigeration and air conditioning units

All of the above

_{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})

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

Energy transferred by convection to that by conduction

Kinematic viscosity to thermal diffusivity

Inertia force to viscous force

None of the above

Grashoff number

Biot number

Stanton number

Prandtl number

Stanton number

Nusselt number

Biot number

Peclet number

Absolute temperature

T²

T⁵

T

Fourier equation

Stefan-Boltzmann equation

Newton Reichmann equation

Joseph-Stefan equation

Grey body

Brilliant white polished body

Red hot body

Black body