Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 270 9 3 81 270 9 3 81 ANSWER DOWNLOAD EXAMIANS APP
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 A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 66.7°C 40°C 20°C 60°C 66.7°C 40°C 20°C 60°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of solid metals with rise in temperature normally Decreases Remain constant Increases May increase or decrease depending on temperature Decreases Remain constant Increases May increase or decrease depending on temperature 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 One Four Two Three One Four Two Three ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by Convection Conduction and convection Radiation Conduction Convection Conduction and convection Radiation Conduction ANSWER DOWNLOAD EXAMIANS APP
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