Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Lower Depends upon the shape of body Higher Same Lower Depends upon the shape of body Higher Same ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k RN = hl/k RN = ρ V l /μ RN = V²/t.cp RN = μ cp/k RN = hl/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Dalton's law of partial pressures, (where pb = Barometric pressure, pa = Partial pressure of dry air, and pv = Partial pressure of water vapour) Pb = pa - pv Pb = pa/pv Pb = pa × pv Pb = pa + pv Pb = pa - pv Pb = pa/pv Pb = pa × pv Pb = pa + pv ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Cork is a good insulator because it has Porous body Low density Free electrons Atoms colliding frequency Porous body Low density Free electrons 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 20°C 66.7°C 60°C 40°C 20°C 66.7°C ANSWER DOWNLOAD EXAMIANS APP
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