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 Thermal conductivity of water _________ with rise in temperature. Remain same Decreases Increases May increase or decrease depending upon temperature Remain same Decreases Increases May increase or decrease depending upon temperature 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 = hl/k RN = μ cp/k RN = V²/t.cp RN = ρ V l /μ RN = hl/k RN = μ cp/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Conduction Conduction and convection Radiation Convection Conduction Conduction and convection Radiation Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain the final temperature to be measured The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 63.2% of the value of initial temperature difference ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/m² hr °C kcal/m hr °C kcal/m² kcal/hr °C kcal/m² hr °C kcal/m hr °C kcal/m² kcal/hr °C ANSWER DOWNLOAD EXAMIANS APP