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 The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to Grashoff number Peclet number Stanton number Biot number Grashoff number Peclet number Stanton number Biot number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following would lead to a reduction in thermal resistance? In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. All of these In convection, stirring of the fluid and cleaning the heating surface. In conduction, reduction in the thickness of the material and an increase in thermal conductivity. In radiation, increasing the temperature and reducing the emissivity. All of these In convection, stirring of the fluid and cleaning the heating surface. ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a Black body Opaque body Grey body White body Black body Opaque body Grey body White body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water _________ with rise in temperature. Remain same Decreases May increase or decrease depending upon temperature Increases Remain same Decreases May increase or decrease depending upon temperature Increases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat exchangers, degree of approach is defined as the difference between temperatures of Hot medium outlet and cold water outlet Cold water inlet and outlet Hot medium inlet and outlet Hot medium outlet and cold water inlet Hot medium outlet and cold water outlet Cold water inlet and outlet Hot medium inlet and outlet Hot medium outlet and cold water inlet ANSWER DOWNLOAD EXAMIANS APP
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