Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Same Lower Depends upon the shape of body Higher Same Lower Depends upon the shape of body Higher ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called None of these Emissivity Absorptive power Emissive power None of these Emissivity Absorptive power Emissive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity) h = kρ/S h = k/ ρS h = ρS/k h = S/ρk h = kρ/S h = k/ ρS h = ρS/k h = S/ρk ANSWER DOWNLOAD EXAMIANS APP
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 81 3 9 270 81 3 9 270 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter flow heat exchangers Both the fluids at inlet are in their hottest state Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state Both the fluids at exit are in their hottest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet are in their hottest state Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state Both the fluids at exit are in their hottest state One fluid is in hottest state and other in coldest state at inlet ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) X = 0, a + p = 0 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 ANSWER DOWNLOAD EXAMIANS APP
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