Composition
Density
Porosity
All of the above
D. All of the above
Wien's law
Stefan's law
Kirchhoff's law
Planck's law
Varies with temperature
Varies with wavelength of the incident ray
Is equal to its emissivity
Does not vary with temperature and. wavelength of the incident ray
P = 0, x = 0 and a = 1
P=1, x = 0, and a = 0
P = 0, T= 1, and a = 0
X = 0, a + p = 1
1 : 1
2 : 1
1 : 2
4 : 1
Change vapour into liquid
Change liquid into vapour
Increase the temperature of a liquid of vapour
Convert water into steam and superheat it
Composition
Density
Porosity
All of the above
Iron
Lead
Concrete
Wood
Higher
Lower
Same
Depends upon the shape of body
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
Kirchhoff's law
Temperature
Thickness
Area
Time
Less than those for gases
Less than those for liquids
More than those for liquids and gases
More or less same as for liquids and gases
Zeroth law of thermodynamics
First law of thermodynamic
Second law of the thermodynamics
Kirchoff's law
One
Two
Three
Four
Quantity of heat flowing in one second through one cm cube of material when opposite faces ^re maintained at a temperature difference of 1°C
Quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C
Heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces
All of the above
m²/hr
m²/hr °C
kcal/m² hr
kcal/m. hr °C
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
2 TR
4 TR
8 TR
10 TR
Conduction
Free convection
Forced convection
Radiation
Blast furnace
Heating of building
Cooling of parts in furnace
Heat received by a person from fireplace
S.H/(S.H + L.H)
(S.H + L.H) /S.H
(L.H - S.H)/S.H
S.H/(L.H - S.H)
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.
High thickness of insulation
High vapour pressure
Less thermal conductivity insulator
A vapour seal
Increase
Decrease
Remain unaffected
May increase/decrease depending on temperature and thickness of insulation
0.002
0.02
0.01
0.1
Solids
Liquids
Gases
None of these
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
Absolute temperature (T)
I²
F
T
Watt/cm² °K
Watt/cm4 °K
Watt²/cm °K⁴
Watt/cm² °K⁴
Change vapour into liquid
Change liquid into vapour
Increase the temperature of a liquid or vapour
Convert water into steam and superheat it
Thermometer
Thermistor
Thermocouple
None of these