Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/m hr °C kcal/hr °C kcal/m² kcal/m² hr °C kcal/m hr °C kcal/hr °C kcal/m² kcal/m² hr °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Newton's law of cooling, the heat transfer from a hot body to a cold body is Either (A) or (B) Directly proportional to the difference of temperatures between the two bodies Directly proportional to the surface area Both (A) and (B) Either (A) or (B) Directly proportional to the difference of temperatures between the two bodies Directly proportional to the surface area Both (A) and (B) 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 = [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)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat transfer, conductance equals conductivity (kcal/hr/sq.m/°C/cm) divided by Sq. m (area) K.cal (heat) °C (temperature) Hr (time) Sq. m (area) K.cal (heat) °C (temperature) Hr (time) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy transferred by convection to that by conduction is called Nusselt number Biot number Peclet number Stanton number Nusselt number Biot number Peclet number Stanton number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of heat flow through a body is Q = [kA (T₁ - T₂)]/x. The term x/kA is known as Thermal conductivity None of these Thermal resistance Thermal coefficient Thermal conductivity None of these Thermal resistance Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP
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