Heat and Mass Transfer According to Stefan Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the Cube of the absolute temperature Fourth power of the absolute temperature Square of the absolute temperature Absolute temperature Cube of the absolute temperature Fourth power of the absolute temperature Square of the absolute temperature Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of glass wool varies from sample to sample because of variation in Density Porosity Composition All of these Density Porosity Composition All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissive power of a body depends upon its Wave length All of these Temperature Physical nature Wave length All of these Temperature Physical nature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be white when (Where a = absorptivity, p = reflectivity, x = transmissivity) 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 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally More than those for solids More than those for liquids Less than those for liquids Dependent on the viscosity More than those for solids More than those for liquids Less than those for liquids Dependent on the viscosity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity) h = S/ρk h = k/ ρS h = ρS/k h = kρ/S h = S/ρk h = k/ ρS h = ρS/k h = kρ/S ANSWER DOWNLOAD EXAMIANS APP