Heat and Mass Transfer A perfect black body is one which Is black in colour Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it Is black in colour Transmits all heat radiations Reflects all heat Absorbs heat radiations of all wave lengths falling on it 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 = (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) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heat transfer will take place mainly by Convection Radiation Free convection Forced convection Convection Radiation Free convection Forced convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Absorptivity of a body will be equal to its emissivity At all temperatures At critical temperature At one particular temperature When system is under thermal equilibrium At all temperatures At critical temperature At one particular temperature When system is under thermal equilibrium ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Conduction is a process of heat transfer From one particle of the body to another by the actual motion of the heated particles From one particle of the body to another without the actual motion of the particles None of these From a hot body to a cold body, in a straight line, without affecting the intervening medium From one particle of the body to another by the actual motion of the heated particles From one particle of the body to another without the actual motion of the particles None of these From a hot body to a cold body, in a straight line, without affecting the intervening medium ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling ANSWER DOWNLOAD EXAMIANS APP
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