Heat and Mass Transfer The most commonly used method for the design of duct size is the Dual or double method Equal friction method Velocity reduction method Static regains method Dual or double method Equal friction method Velocity reduction method Static regains method 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/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of Prandtl number for air is about 0.7 0.3 1.7 0.1 0.7 0.3 1.7 0.1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer by radiation mainly depends upon Nature of the body Kind and extent of its surface Its temperature All of these Nature of the body Kind and extent of its surface Its temperature All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the energy absorbed by the body to total energy falling on it is called Absorptivity Emissivity Absorptive power Emissive power Absorptivity Emissivity Absorptive power Emissive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Sensible heat factor is given by (where S.H. = Sensible heat, and L.H. = Latent heat) S.H/(S.H + L.H) (L.H - S.H)/S.H S.H/(L.H - S.H) (S.H + L.H) /S.H S.H/(S.H + L.H) (L.H - S.H)/S.H S.H/(L.H - S.H) (S.H + L.H) /S.H ANSWER DOWNLOAD EXAMIANS APP
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