Heat and Mass Transfer The amount of radiation mainly depends on Nature of body Temperature of body All of these Type of surface of body Nature of body Temperature of body All of these Type of surface of body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to =-2/3 1 -1 =-1/3 =-2/3 1 -1 =-1/3 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 = 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 The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit Temperature Thickness Time Area Temperature Thickness Time Area ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A composite slab has two layers of different materials with thermal conductivities k₁ and k₂. If each layer has the same thickness, then the equivalent thermal conductivity of the slab will be k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Intensity of radiation Emissivity Reflectivity Transmissivity Intensity of radiation Emissivity Reflectivity Transmissivity ANSWER DOWNLOAD EXAMIANS APP