Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.45 0.4 0.55 0.75 0.45 0.4 0.55 0.75 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fouling factor is used In heat exchanger design as a safety factor None of these In case of Newtonian fluids When a liquid exchanges heat with a gas In heat exchanger design as a safety factor None of these In case of Newtonian fluids When a liquid exchanges heat with a gas ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water at 20°C is of the order of 0.42 0.51 0.1 0.23 0.42 0.51 0.1 0.23 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Four One Three Two Four One Three Two ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Is black in colour Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations Is black in colour Absorbs heat radiations of all wave lengths falling on it Reflects all heat Transmits all heat radiations ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a shell and tube heat exchanger, baffles are provided on the shell side to Prevent stagnation of shell side fluid Improve heat transfer Provide support for tubes All of these Prevent stagnation of shell side fluid Improve heat transfer Provide support for tubes All of these ANSWER DOWNLOAD EXAMIANS APP
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