Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called First law of thermodynamics Newton's law of heating Newton's law of cooling Stefan's law First law of thermodynamics Newton's law of heating Newton's law of cooling Stefan's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally 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 Less than those for liquids More than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In case of liquids and gases, the heat transfer takes place according to Convection Radiation None of these Conduction Convection Radiation None of these 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 = hl/k RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k RN = hl/k RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles due to difference of density caused by temperature of the particle is known as Radiation Conduction Forced convection Free convection Radiation Conduction Forced convection Free convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In regenerator type heat exchanger, heat transfer takes place by A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Generation of heat again and again Direct mixing of hot and cold fluids A complete separation between hot and cold fluids Flow of hot and cold fluids alternately over a surface Generation of heat again and again Direct mixing of hot and cold fluids ANSWER DOWNLOAD EXAMIANS APP
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