Heat and Mass Transfer According of Kirchhoff's law Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer, One could place either insulation on either side The better insulation must be put outside One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put inside One could place either insulation on either side The better insulation must be put outside One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put inside 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) P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x = 1 and a = 0 P=1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x = 1 and a = 0 P=1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally More or less same as for liquids and gases Less than those for liquids More than those for liquids and gases Less than those for gases More or less same as for liquids and gases Less than those for liquids More than those for liquids and gases Less than those for gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The insulation ability of an insulator with the presence of moisture would May increase/decrease depending on temperature and thickness of insulation Increase Decrease Remain unaffected May increase/decrease depending on temperature and thickness of insulation Increase Decrease Remain unaffected 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 =-2/3 1 -1 =-1/3 =-2/3 1 -1 =-1/3 ANSWER DOWNLOAD EXAMIANS APP
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