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 value of Prandtl number for air is about 1.7 0.1 0.3 0.7 1.7 0.1 0.3 0.7 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature Increases May increase or decrease depending on temperature Decreases Remain constant Increases May increase or decrease depending on temperature Decreases Remain constant ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is valid for One dimensional cases only Regular surfaces having non-uniform temperature gradients Two dimensional cases only Three dimensional cases only One dimensional cases only Regular surfaces having non-uniform temperature gradients Two dimensional cases only Three dimensional cases only ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? None of these I.C. engine Heating of building in winter Air preheaters None of these I.C. engine Heating of building in winter Air preheaters ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The most commonly used method for the design of duct size is the Dual or double method Equal friction method Static regains method Velocity reduction method Dual or double method Equal friction method Static regains method Velocity reduction method ANSWER DOWNLOAD EXAMIANS APP
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