Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm2 °K⁴ watt2/cm °K⁴ watt/cm3 °K watt/cm4 °K watt/cm2 °K⁴ watt2/cm °K⁴ watt/cm3 °K watt/cm4 °K 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 = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 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 The expression Q = ρ AT4 is called Fourier equation Joseph-Stefan equation Stefan-Boltzmann equation Newton Reichmann equation Fourier equation Joseph-Stefan equation Stefan-Boltzmann equation Newton Reichmann equation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissive power of a body depends upon its Physical nature All of these Wave length Temperature Physical nature All of these Wave length Temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A grey body is one whose absorptivity Varies with wavelength of the incident ray Is equal to its emissivity Varies with temperature Does not vary with temperature and. wavelength of the incident ray Varies with wavelength of the incident ray Is equal to its emissivity Varies with temperature Does not vary with temperature and. wavelength of the incident ray ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity ANSWER DOWNLOAD EXAMIANS APP
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