Heat and Mass Transfer Stefan Boltzmann law is applicable for heat transfer by Radiation Conduction and radiation combined Convection Conduction Radiation Conduction and radiation combined Convection Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = V²/t.cp RN = ρ V l /μ RN = μ cp/k RN = hl/k RN = V²/t.cp RN = ρ V l /μ RN = μ cp/k RN = hl/k 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 Three Two Four One Three Two Four One ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally Less than those for liquids More than those for liquids Dependent on the viscosity More than those for solids Less than those for liquids More than those for liquids Dependent on the viscosity More than those for solids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to one Equal to Nusselt number Less than one Greater than one Equal to one Equal to Nusselt number Less than one Greater than one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 60°C 66.7°C 20°C 40°C 60°C 66.7°C 20°C 40°C ANSWER DOWNLOAD EXAMIANS APP
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