Heat and Mass Transfer According to Dalton's law of partial pressures, (where pb = Barometric pressure, pa = Partial pressure of dry air, and pv = Partial pressure of water vapour) Pb = pa - pv Pb = pa + pv Pb = pa × pv Pb = pa/pv Pb = pa - pv Pb = pa + pv Pb = pa × pv Pb = pa/pv 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 = 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) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wave length for maximum emissive power is given by Wine’s law Planck’s law Stefan’s law Kirchhoff’s law Wine’s law Planck’s law Stefan’s law Kirchhoff’s law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The use of heat exchangers is made in All of these 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 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature Remain constant May increase or decrease depending on temperature Increases Decreases Remain constant May increase or decrease depending on temperature Increases Decreases ANSWER DOWNLOAD EXAMIANS APP