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 Thermal diffusivity is Used as mathematical model A physical property of the material Function of temperature A dimensionless parameter Used as mathematical model A physical property of the material Function of temperature A dimensionless parameter ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.55 0.45 0.4 0.75 0.55 0.45 0.4 0.75 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The automobile radiator is a heat exchanger of Counter flow type Regenerator type Parallel flow type Cross flow type Counter flow type Regenerator type Parallel flow type Cross flow type ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat of sun reaches to us according to Radiation None of these Conduction Convection Radiation None of these Conduction Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to Nusselt number Less than one Greater than one Equal to one Equal to Nusselt number Less than one Greater than one Equal to one ANSWER DOWNLOAD EXAMIANS APP
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