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 = (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) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, body will be transparent when(Where a = absorptivity, p = reflectivity, x = transmissivity) P=1, x = 0, and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P=1, x = 0, and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x= 1, and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by Conduction Both convection and conduction Convection Radiation Conduction Both convection and conduction Convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Steel Brass Copper Aluminium Steel Brass Copper Aluminium ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be lined with two layers of insulating materials of different thermal conductivities. For the minimum heat transfer, The better insulation must be put inside One could place either insulation on either side One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put outside The better insulation must be put inside One could place either insulation on either side One should take into account the steam temperature before deciding as to which insulation is put where The better insulation must be put outside ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The product of Reynolds number and Prandtl number is known as Stanton number Peclet number Grashoff number Biot number Stanton number Peclet number Grashoff number Biot number ANSWER DOWNLOAD EXAMIANS APP
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