Heat and Mass Transfer Unit of thermal conductivity in S.I. units is J/m² sec J/m °K sec Option (B) and (C) above W/m °K J/m² sec J/m °K sec Option (B) and (C) above W/m °K ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The expression Q = ρ AT4 is called Joseph-Stefan equation Fourier equation Stefan-Boltzmann equation Newton Reichmann equation Joseph-Stefan equation Fourier equation Stefan-Boltzmann equation Newton Reichmann equation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is smallest in Gases Liquids None of these Solids Gases Liquids None of these Solids 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 = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Reflectivity Transmissivity Emissivity Intensity of radiation Reflectivity Transmissivity Emissivity Intensity of radiation 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 Less than one Equal to Nusselt number Greater than one Equal to one Less than one Equal to Nusselt number Greater than one ANSWER DOWNLOAD EXAMIANS APP