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 =-2/3 =-1/3 1 -1 =-2/3 =-1/3 1 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 Four Three One Two Four Three One Two ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical thickness of insulation for a sphere is 2k/h₀ h₀/k k/h₀ h₀/2k 2k/h₀ h₀/k k/h₀ h₀/2k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer by radiation mainly depends upon Nature of the body All of these Kind and extent of its surface Its temperature Nature of the body All of these Kind and extent of its surface Its temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally Less than those for liquids More than those for solids Dependent on the viscosity More than those for liquids Less than those for liquids More than those for solids Dependent on the viscosity More than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as the ratio of Thickness of film of fluid to the thermal conductivity Thickness of film of fluid to the temperature drop through the films of fluids Temperature drop through the films of fluids to the thickness of film of fluids Thermal conductivity to the equivalent thickness of the film of fluid Thickness of film of fluid to the thermal conductivity Thickness of film of fluid to the temperature drop through the films of fluids Temperature drop through the films of fluids to the thickness of film of fluids Thermal conductivity to the equivalent thickness of the film of fluid ANSWER DOWNLOAD EXAMIANS APP
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