Heat and Mass Transfer The thermal diffusivities for solids are generally More or less same as for liquids and gases Less than those for liquids Less than those for gases More than those for liquids and gases More or less same as for liquids and gases Less than those for liquids Less than those for gases More than those for liquids and gases 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
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Greater than one Less than one Equal to Nusselt number Equal to one Greater than one Less than one Equal to Nusselt number Equal to one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is smallest in Liquids Gases None of these Solids Liquids Gases None of these Solids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water at 20°C is of the order of 0.1 0.42 0.23 0.51 0.1 0.42 0.23 0.51 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Lower Higher Depends upon the shape of body Same Lower Higher Depends upon the shape of body Same ANSWER DOWNLOAD EXAMIANS APP
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