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 = 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) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Moisture would find its way into insulation by vapour pressure unless it is prevented by High thickness of insulation A vapour seal Less thermal conductivity insulator High vapour pressure High thickness of insulation A vapour seal Less thermal conductivity insulator High vapour pressure ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = V²/t.cp RN = hl/k RN = ρ V l /μ RN = μ cp/k RN = V²/t.cp RN = hl/k RN = ρ V l /μ RN = μ cp/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Less than one Equal to Nusselt number Greater than one Equal to one Less than one Equal to Nusselt number Greater than one Equal to one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The product of Reynolds number and Prandtl number is known as Stanton number Grashoff number Biot number Peclet number Stanton number Grashoff number Biot number Peclet number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these ANSWER DOWNLOAD EXAMIANS APP
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