Heat and Mass Transfer The most commonly used method for the design of duct size is the Dual or double method Static regains method Equal friction method Velocity reduction method Dual or double method Static regains method Equal friction method Velocity reduction method ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) k. A. (dT/dx) k. (dT/dx) k. A. (dx/dT) k. (dx/dT) k. A. (dT/dx) k. (dT/dx) k. A. (dx/dT) k. (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is known as Conduction Convection None of these Radiation Conduction Convection None of these Radiation 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 = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In case of liquids and gases, the heat transfer takes place according to Convection None of these Conduction Radiation Convection None of these Conduction Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissive power of a body depends upon its Wave length All of these Temperature Physical nature Wave length All of these Temperature Physical nature ANSWER DOWNLOAD EXAMIANS APP
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