Heat and Mass Transfer The emissivity for a black body is 0.75 0.5 1 0.75 0.5 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wave length for maximum emissive power is given by Planck’s law Stefan’s law Wine’s law Kirchhoff’s law Planck’s law Stefan’s law Wine’s law Kirchhoff’s law 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 A perfect black body is one which Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A non-dimensional number generally associated with natural convection heat transfer is Weber number Nusselt number Grashoff number Prandtl number Weber number Nusselt number Grashoff number Prandtl number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan's law, the total radiation from a black body per second per unit area is proportional to Absolute temperature T2 T T5 Absolute temperature T2 T T5 ANSWER DOWNLOAD EXAMIANS APP
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