Heat and Mass Transfer Thermal conductivity of non-metallic amorphous solids with decrease 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 In heat exchangers, degree of approach is defined as the difference between temperatures of Hot medium outlet and cold water inlet Hot medium inlet and outlet Hot medium outlet and cold water outlet Cold water inlet and outlet Hot medium outlet and cold water inlet Hot medium inlet and outlet Hot medium outlet and cold water outlet Cold water inlet and outlet 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 = 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) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 66.7°C 20°C 60°C 40°C 66.7°C 20°C 60°C 40°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of glass wool varies from sample to sample because of variation in Porosity All of these Composition Density Porosity All of these Composition Density ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The use of heat exchangers is made in Condensers and boilers in steam plants Condensers and evaporators in refrigeration and air conditioning units Radiators in automobile All of these Condensers and boilers in steam plants Condensers and evaporators in refrigeration and air conditioning units Radiators in automobile All of these ANSWER DOWNLOAD EXAMIANS APP