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 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 Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.043055555555556 0.16736111111111 0.084027777777778 0.042361111111111 0.043055555555556 0.16736111111111 0.084027777777778 0.042361111111111 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat transfer, conductance equals conductivity (kcal/hr/sq.m/°C/cm) divided by K.cal (heat) Sq. m (area) Hr (time) °C (temperature) K.cal (heat) Sq. m (area) Hr (time) °C (temperature) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the energy absorbed by the body to total energy falling on it is called Emissivity Absorptive power Emissive power Absorptivity Emissivity Absorptive power Emissive power Absorptivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a shell and tube heat exchanger, baffles are provided on the shell side to Provide support for tubes Improve heat transfer Prevent stagnation of shell side fluid All of these Provide support for tubes Improve heat transfer Prevent stagnation of shell side fluid All of these ANSWER DOWNLOAD EXAMIANS APP
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