Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Greater than one Equal to one Equal to Nusselt number Less than one Greater than one Equal to one Equal to Nusselt number Less than one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The most commonly used method for the design of duct size is the Equal friction method Static regains method Velocity reduction method Dual or double method Equal friction method Static regains method Velocity reduction method Dual or double method ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of non-metallic amorphous solids with decrease in temperature Remain constant Increases Decreases May increase or decrease depending on temperature Remain constant Increases Decreases May increase or decrease depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Absorptivity of a body will be equal to its emissivity At critical temperature When system is under thermal equilibrium At one particular temperature At all temperatures At critical temperature When system is under thermal equilibrium At one particular temperature At all temperatures ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A heat exchanger with heat transfer surface area A and overall heat transfer coefficient U handles two fluids of heat capacities Cmax and Cmin. The number of transfer units (NTU) used in the analysis of heat exchanger is specified as U/Cmin Cmin/U U/A.Cmin U.Cmin U/Cmin Cmin/U U/A.Cmin U.Cmin ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP