Heat and Mass Transfer According of Kirchhoff's law Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Emissive power and absorptivity are constant for all bodies Radiant heat is proportional to fourth power of absolute temperature Ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body Emissive power depends on temperature Emissive power and absorptivity are constant for all bodies Radiant heat is proportional to fourth power of absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous body, α = 0, ρ = 1 and τ = 0 α + ρ = 1 and τ = 0 α = 0, ρ = 0 and τ = 1 α = 1, ρ = 0 and τ = 0 α = 0, ρ = 1 and τ = 0 α + ρ = 1 and τ = 0 α = 0, ρ = 0 and τ = 1 α = 1, ρ = 0 and τ = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer takes place as per Kirchoff's law First law of thermodynamic Second law of the thermodynamics Zeroth law of thermodynamics Kirchoff's law First law of thermodynamic Second law of the thermodynamics Zeroth law of thermodynamics ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law. Directly proportional to None of these Inversely proportional to Equal to Directly proportional to None of these Inversely proportional to Equal to ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 800 mm 160 mm 25 mm 40 mm 800 mm 160 mm 25 mm 40 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissivity for a black body is 1 0.5 0.75 1 0.5 0.75 ANSWER DOWNLOAD EXAMIANS APP
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