Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to Fourth power of absolute temperature Square of temperature Absolute temperature Fourth power of temperature Fourth power of absolute temperature Square of temperature Absolute temperature Fourth power of temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Conduction and convection Convection Conduction Radiation Conduction and convection Convection Conduction Radiation 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 = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Unit of thermal conductivity in M.K.S. units is K cal/hr m² °C K cal m/hr m² °C K calm/hr °C K cal/kg m² °C K cal/hr m² °C K cal m/hr m² °C K calm/hr °C K cal/kg m² °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred by molecular collision, it is referred to as heat transfer by Radiation Convection Scattering Conduction Radiation Convection Scattering Conduction 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 All of these Radiators in automobile Condensers and boilers in steam plants Condensers and evaporators in refrigeration and air conditioning units All of these Radiators in automobile ANSWER DOWNLOAD EXAMIANS APP