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 Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.042361111111111 0.043055555555556 0.16736111111111 0.084027777777778 0.042361111111111 0.043055555555556 0.16736111111111 0.084027777777778 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The energy distribution of an ideal reflector at higher temperatures is largely in the range of Wavelength has nothing to do with it Remain same at all wavelengths Longer wavelength Shorter wavelength Wavelength has nothing to do with it Remain same at all wavelengths Longer wavelength Shorter wavelength ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles due to difference of density caused by temperature of the particle is known as Forced convection Free convection Conduction Radiation Forced convection Free convection Conduction Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a shell and tube heat exchanger, baffles are provided on the shell side to Improve heat transfer Provide support for tubes All of these Prevent stagnation of shell side fluid Improve heat transfer Provide support for tubes All of these Prevent stagnation of shell side fluid ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An ordinary passenger aircraft requires a cooling system of capacity. 4 TR 10 TR 8 TR 2 TR 4 TR 10 TR 8 TR 2 TR ANSWER DOWNLOAD EXAMIANS APP
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