Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to 1 =-2/3 -1 =-1/3 1 =-2/3 -1 =-1/3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Kirchoff's law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a Grey body Red hot body Black body Brilliant white polished body Grey body Red hot body Black body Brilliant white polished body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissive power of a body depends upon its All of these Physical nature Wave length Temperature All of these Physical nature Wave length Temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fouling factor is used When a liquid exchanges heat with a gas In heat exchanger design as a safety factor In case of Newtonian fluids None of these When a liquid exchanges heat with a gas In heat exchanger design as a safety factor In case of Newtonian fluids None of these 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 = (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) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Pick up the wrong case. Heat flowing from one side to other depends directly on Time Face area Thickness Temperature difference Time Face area Thickness Temperature difference ANSWER DOWNLOAD EXAMIANS APP