AP EAPCET 04-Jul-2022 Shift 1 Paper

Given surface area of sphere, A=4m2
Temperature, T=400K
Emissivity, ε=0.5
Environment temperature,
T0=200K
Sțefan Boltzmann constant, σ=567×10−8Wm−2K4
According to stefan Boltzmann law, rate of energy exchange of the sphere
E‌=εσA(T4−T04)
‌=0.5×5.67×10−8×4(4004−2004)
‌=27216×103W=2721.6W