The sun radiates electromagnetic energy at the rate of $3.9 \times 10^{26}W$. Its radius is $6.96 \times 10^8m$,
The intensity of sun light at the solar surface will be:
Answer & explanation
Correct answer: option 4
$ I = \frac{P}{A} = \frac{P}{4\pi R^2} = \frac{3.9\times 10^26}{4\pi \times (6.9\times 10^8)^2} = 5.6\times 10^7 W/m^2$