Heat and Mass Transfer A perfect black body is one which Absorbs heat radiations of all wave lengths falling on it Is black in colour Reflects all heat Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Is black in colour Reflects all heat Transmits all heat radiations 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= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 1 and a = 0 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 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer All radiations in a black body are Transmitted Absorbed Reflected Refracted Transmitted Absorbed Reflected Refracted ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Stefan Boltzmann law is applicable for heat transfer by Conduction Radiation Convection Conduction and radiation combined Conduction Radiation Convection Conduction and radiation combined 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 Thermal coefficient None of these Thermal resistance Thermal conductivity Thermal coefficient None of these Thermal resistance ANSWER DOWNLOAD EXAMIANS APP
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