Heat and Mass Transfer According to Newton's law of cooling, the heat transfer from a hot body to a cold body is Either (A) or (B) Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Directly proportional to the surface area Either (A) or (B) Both (A) and (B) Directly proportional to the difference of temperatures between the two bodies Directly proportional to the surface area ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical radius is the insulation radius at which the resistance to heat flow is Maximum None of these Minimum Zero Maximum None of these Minimum Zero ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to Biot number Grashoff number Stanton number Peclet number Biot number Grashoff number Stanton number Peclet number 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 = 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) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature Increases Decreases Remain constant May increase or decrease depending on temperature Increases Decreases Remain constant May increase or decrease depending on temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to =-1/3 1 =-2/3 -1 =-1/3 1 =-2/3 -1 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS