Heat and Mass Transfer Thermal diffusivity of a substance is Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these Inversely proportional to specific heat Directly proportional to the thermal conductivity Inversely proportional to density of substance All of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wavelength for maximum emissive power is given by Fourier's law Wien’s law Stefan's law Planck's law Fourier's law Wien’s law Stefan's law Planck's law 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 = 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) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Radiation Conduction Convection Conduction and convection Radiation Conduction Convection Conduction and convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 X = 0, a + p = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, body will be transparent when(Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 X = 0, a + p = 1 P = 0, x= 1, and a = 0 ANSWER DOWNLOAD EXAMIANS APP