Heat and Mass Transfer Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity) h = S/ρk h = ρS/k h = k/ ρS h = kρ/S h = S/ρk h = ρS/k h = k/ ρS h = kρ/S 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 = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The most commonly used method for the design of duct size is the Equal friction method Static regains method Velocity reduction method Dual or double method Equal friction method Static regains method Velocity reduction method Dual or double method ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The use of heat exchangers is made in Condensers and boilers in steam plants Radiators in automobile Condensers and evaporators in refrigeration and air conditioning units All of these Condensers and boilers in steam plants Radiators in automobile Condensers and evaporators in refrigeration and air conditioning units All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy transferred by convection to that by conduction is called Biot number Peclet number Nusselt number Stanton number Biot number Peclet number Nusselt number Stanton number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? I.C. engine None of these Air preheaters Heating of building in winter I.C. engine None of these Air preheaters Heating of building in winter ANSWER DOWNLOAD EXAMIANS APP
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