Heat and Mass Transfer Kirchhoff's law states that The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of 0.1 0.01 0.02 0.002 0.1 0.01 0.02 0.002 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by Both convection and conduction Conduction Convection Radiation Both convection and conduction Conduction Convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations Is black in colour Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations Is black in colour 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 Which of the following is expected to have highest thermal conductivity? Solid ice Water Melting ice Steam Solid ice Water Melting ice Steam ANSWER DOWNLOAD EXAMIANS APP
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