Heat and Mass Transfer Depending on the radiating properties, body will be transparent when (Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P = 0, x= 1, and a = 0 X = 0, a + p = 1 P=1, x = 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, x = 0, and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction gives the heat flow for One dimensional cases only Two dimensional cases only Irregular surfaces Nonuniform temperature surfaces One dimensional cases only Two dimensional cases only Irregular surfaces Nonuniform temperature surfaces ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In radiation, increasing the temperature and reducing the emissivity. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. All of these In convection, stirring of the fluid and cleaning the heating surface. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be One Three Two Four One Three Two Four ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The insulation ability of an insulator with the presence of moisture would Increase Remain unaffected May increase/decrease depending on temperature and thickness of insulation Decrease Increase Remain unaffected May increase/decrease depending on temperature and thickness of insulation Decrease ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The expression Q = ρ AT4 is called Stefan-Boltzmann equation Fourier equation Joseph-Stefan equation Newton Reichmann equation Stefan-Boltzmann equation Fourier equation Joseph-Stefan equation Newton Reichmann equation ANSWER DOWNLOAD EXAMIANS APP
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