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)/ k₁ k₂ (k₁ + k₂) k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) ANSWER DOWNLOAD EXAMIANS APP
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 Reynolds number is the ratio of Energy transferred by convection to that by conduction Inertia force to viscous force None of these Kinematic viscosity to thermal diffusivity Energy transferred by convection to that by conduction Inertia force to viscous force None of these Kinematic viscosity to thermal diffusivity 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= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of Prandtl number for air is about 0.7 1.7 0.3 0.1 0.7 1.7 0.3 0.1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Unit of thermal diffusivity is kcal/m. hr °C kcal/m² hr m²/hr m²/hr °C kcal/m. hr °C kcal/m² hr m²/hr m²/hr °C ANSWER DOWNLOAD EXAMIANS APP