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 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 0 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 = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by Conduction Radiation Convection Conduction and convection Conduction Radiation Convection Conduction and convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In convection, stirring of the fluid and cleaning the heating surface. All of these In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. In convection, stirring of the fluid and cleaning the heating surface. All of these In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to =-1/3 -1 =-2/3 1 =-1/3 -1 =-2/3 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of non-metallic amorphous solids with decrease in temperature Increases Remain constant Decreases May increase or decrease depending on temperature Increases Remain constant Decreases May increase or decrease depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for polished bodies All of these all coloured bodies black bodies polished bodies All of these all coloured bodies black bodies ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS