Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.45 0.75 0.4 0.55 0.45 0.75 0.4 0.55 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called None of these Convection Radiation Conduction None of these Convection Radiation Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to Fourth power of temperature Absolute temperature Square of temperature Fourth power of absolute temperature Fourth power of temperature Absolute temperature Square of temperature Fourth power of absolute temperature 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 = V²/t.cp RN = μ cp/k RN = ρ V l /μ RN = hl/k RN = V²/t.cp RN = μ cp/k RN = ρ V l /μ RN = hl/k ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Prevost theory of heat exchange Heat transfer in most of the cases takes place by combination of conduction, convection and radiation Heat transfer by radiation requires no medium All bodies above absolute zero emit radiation It is impossible to transfer heat from low temperature source to t high temperature source Heat transfer in most of the cases takes place by combination of conduction, convection and radiation Heat transfer by radiation requires no medium All bodies above absolute zero emit radiation It is impossible to transfer heat from low temperature source to t high temperature source ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer takes place according to Zeroth law of thermodynamics First law of thermodynamics Kirchhoff's law Second law of thermodynamics Zeroth law of thermodynamics First law of thermodynamics Kirchhoff's law Second law of thermodynamics ANSWER DOWNLOAD EXAMIANS APP
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