Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called Emissive power Absorptive power None of these Emissivity Emissive power Absorptive power None of these Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in heat transfer problems of Conduction and convection Convection Conduction Radiation Conduction and convection Convection Conduction Radiation 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 k₁ k₂ (k₁ + k₂) 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ k₁ k₂ (k₁ + k₂) 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following property of air does not increase with rise in temperature? Thermal diffusivity Dynamic viscosity Thermal conductivity Density Thermal diffusivity Dynamic viscosity Thermal conductivity Density ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Dalton's law of partial pressures, (where pb = Barometric pressure, pa = Partial pressure of dry air, and pv = Partial pressure of water vapour) Pb = pa × pv Pb = pa/pv Pb = pa + pv Pb = pa - pv Pb = pa × pv Pb = pa/pv Pb = pa + pv Pb = pa - pv 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
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