Heat and Mass Transfer According of Kirchhoff's law Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Radiant heat is proportional to fourth power of absolute temperature Emissive power and absorptivity are constant for all bodies ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Reflectivity Emissivity Transmissivity Intensity of radiation Reflectivity Emissivity Transmissivity Intensity of radiation 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 20°C 60°C 66.7°C 40°C 20°C 60°C 66.7°C 40°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature May increase or decrease depending on temperature Remain constant Increases Decreases May increase or decrease depending on temperature Remain constant Increases Decreases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of wood depends on Temperature Density All of these Moisture Temperature Density All of these Moisture ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous body, α + ρ = 1 and τ = 0 α = 0, ρ = 1 and τ = 0 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 α + ρ = 1 and τ = 0 α = 0, ρ = 1 and τ = 0 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 0 and τ = 1 ANSWER DOWNLOAD EXAMIANS APP
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