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 = 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) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter current flow heat exchanger, the logarithmic temperature difference between the fluids is ________ as compared to parallel flow heat exchanger. Same None of these Less Greater Same None of these Less Greater ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction gives the heat flow for Two dimensional cases only Nonuniform temperature surfaces One dimensional cases only Irregular surfaces Two dimensional cases only Nonuniform temperature surfaces One dimensional cases only Irregular surfaces ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A composite slab has two layers of different materials with thermal conductivities k₁ and k₂. If each layer has the same thickness, then the equivalent thermal conductivity of the slab will be 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂) k₁ k₂ (k₁ + k₂)/ k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂) k₁ k₂ (k₁ + k₂)/ k₁ k₂ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the Grashoff's number Prandtl number, Grashoff's number Reynold's number Reynold's number, Grashoff's number Grashoff's number Prandtl number, Grashoff's number Reynold's number Reynold's number, Grashoff's number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer LMTD in case of counter flow heat exchanger as compared to parallel flow heat exchanger is Lower Depends on the area of heat exchanger Same Higher Lower Depends on the area of heat exchanger Same Higher ANSWER DOWNLOAD EXAMIANS APP