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 3 81 270 9 3 81 270 9 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Cork is a good insulator because it has Free electrons Porous body Low density Atoms colliding frequency Free electrons Porous body Low density Atoms colliding frequency 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 60°C 40°C 66.7°C 20°C 60°C 40°C 66.7°C 20°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally More than those for liquids Less than those for liquids More than those for solids Dependent on the viscosity More than those for liquids Less than those for liquids More than those for solids Dependent on the viscosity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fouling factor is used In heat exchanger design as a safety factor None of these When a liquid exchanges heat with a gas In case of Newtonian fluids In heat exchanger design as a safety factor None of these When a liquid exchanges heat with a gas In case of Newtonian fluids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) k. A. (dT/dx) k. (dx/dT) k. (dT/dx) k. A. (dx/dT) k. A. (dT/dx) k. (dx/dT) k. (dT/dx) k. A. (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
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