Heat and Mass Transfer Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P=1, T = 0 and a = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Two Four Three One Two Four Three One ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A perfect black body is one which Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it Reflects all heat Is black in colour Transmits all heat radiations Absorbs heat radiations of all wave lengths falling on it ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm2 °K⁴ watt/cm3 °K watt/cm4 °K watt2/cm °K⁴ watt/cm2 °K⁴ watt/cm3 °K watt/cm4 °K watt2/cm °K⁴ ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is given by (where h = Thermal diffusivity, ρ = Density of substance, S = Specific heat, and k = Thermal conductivity) h = ρS/k h = k/ ρS h = kρ/S h = S/ρk h = ρS/k h = k/ ρS h = kρ/S h = S/ρk ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The highest thermal diffusivity is of Lead Iron Wood Concrete Lead Iron Wood Concrete ANSWER DOWNLOAD EXAMIANS APP
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