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 The ratio of the energy absorbed by the body to total energy falling on it is called Emissive power Absorptivity Emissivity Absorptive power Emissive power Absorptivity Emissivity Absorptive power ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.55 0.4 0.75 0.45 0.55 0.4 0.75 0.45 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total emissivity of polished silver compared to black body is Same Very much lower More or less same Higher Same Very much lower More or less same Higher ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred from hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by Conduction and convection Radiation Convection Conduction Conduction and convection Radiation Convection Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The amount of radiation mainly depends on Type of surface of body Nature of body Temperature of body All of these Type of surface of body Nature of body Temperature of body All of these ANSWER DOWNLOAD EXAMIANS APP