Heat and Mass Transfer Kirchhoff's law states that The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body None of these The wave length corresponding to the maximum energy is proportional to the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The value of the wavelength for maximum emissive power is given by Fourier's law Stefan's law Planck's law Wien’s law Fourier's law Stefan's law Planck's law Wien’s law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity) RN = μ cp/k RN = V²/t.cp RN = hl/k RN = ρ V l /μ RN = μ cp/k RN = V²/t.cp RN = hl/k RN = ρ V l /μ ANSWER DOWNLOAD EXAMIANS APP
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 Emissivity Emissive power Absorptive power None of these Emissivity Emissive power Absorptive power None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A non-dimensional number generally associated with natural convection heat transfer is Grashoff number Nusselt number Weber number Prandtl number Grashoff number Nusselt number Weber number Prandtl number 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 Convection Conduction and convection Radiation Conduction Convection Conduction and convection Radiation ANSWER DOWNLOAD EXAMIANS APP
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