Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is All of these Inversely proportional to density of substance Inversely proportional to specific heat Directly proportional to the thermal conductivity All of these Inversely proportional to density of substance Inversely proportional to specific heat Directly proportional to the thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is known as Convection Radiation None of these Conduction Convection Radiation None of these Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical thickness of insulation for a sphere is 2k/h₀ k/h₀ h₀/k h₀/2k 2k/h₀ k/h₀ h₀/k h₀/2k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Intensity of radiation Emissivity Transmissivity Reflectivity Intensity of radiation Emissivity Transmissivity Reflectivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law. None of these Equal to Inversely proportional to Directly proportional to None of these Equal to Inversely proportional to Directly proportional to ANSWER DOWNLOAD EXAMIANS APP