Heat and Mass Transfer Depending on the radiating properties, a body will be white when (Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 1 P=1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm4 °K watt/cm3 °K watt2/cm °K⁴ watt/cm2 °K⁴ watt/cm4 °K watt/cm3 °K watt2/cm °K⁴ watt/cm2 °K⁴ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity is A dimensionless parameter Used as mathematical model Function of temperature A physical property of the material A dimensionless parameter Used as mathematical model Function of temperature A physical property of the material ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Better insulation should be put over pipe and better one over it Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Both may be put in any order Better insulation should be put over pipe and better one over it Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Both may be put in any order ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wave length for maximum emissive power is given by Stefan’s law Wine’s law Planck’s law Kirchhoff’s law Stefan’s law Wine’s law Planck’s law Kirchhoff’s law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP