Answer 1

Given:-

T = 727 + 273 = 1000 K,

σ = 5.7 x 10^-8 J/m²sK⁴, e = 0.2

To find:- Power radiated (E)

Formula:-

`(E)Q/(At)=sigmaeT^4`

Calculation:- From formula,

E = 0.2 x 5.7 x 10^-8 x (1000)⁴

    ^{= 11400}

∴ E = 1.14 x 10⁴ watt/m²

The power radiated per unit area is 1.14 x 10⁴ watt/m².