The sun radiates electromagnetic energy at the rate of 3.9 × 10²⁶ W. Its radius is 6.96 × 10⁸ m. if the distance from the sun to the earth is 1.5 × 10¹¹ m, then the intensity of sunlight on earth's surface will be-(in W/m²)

1.38 × 10³

I_earth = $\frac{P}{A}=\frac{3.9 \times 10^{26}}{4 \times 3.14 \times(6.96)^2 \times 10^{16}}$ = 1.38 × 10³ W/m²