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 A perfect black body is one which Is black in colour Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations Is black in colour Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat flows from one body to other when they have Different heat contents Different specific heat Different atomic structure Different temperatures Different heat contents Different specific heat Different atomic structure Different temperatures ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature Decreases May increase or decrease depending on temperature Remain constant Increases Decreases May increase or decrease depending on temperature Remain constant Increases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical thickness of insulation for a sphere is h₀/k h₀/2k 2k/h₀ k/h₀ h₀/k h₀/2k 2k/h₀ k/h₀ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Radiation is the process of heat transfer in which heat flows from a ________, in a straight line, without affecting the intervening medium. Hot body to cold body Cold body to hot body Smaller body to larger body Larger body to smaller body Hot body to cold body Cold body to hot body Smaller body to larger body Larger body to smaller body ANSWER DOWNLOAD EXAMIANS APP
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