Heat and Mass Transfer Depending on the radiating properties, a body will be white when (Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P=1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Inferior insulation should be put over pipe and better one over it Both may be put in any order Better insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Inferior insulation should be put over pipe and better one over it Both may be put in any order Better insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for all coloured bodies black bodies polished bodies All of these all coloured bodies black bodies polished bodies All of these 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 = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The most commonly used method for the design of duct size is the Velocity reduction method Static regains method Dual or double method Equal friction method Velocity reduction method Static regains method Dual or double method Equal friction method ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is known as Convection Conduction None of these Radiation Convection Conduction None of these Radiation ANSWER DOWNLOAD EXAMIANS APP
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