Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Electromagnetic Waves

Question:
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:
Options:
$1.4\times 10^4 W/m^2$
$2.8 \times 10^5 W/m^2$
$4.2\times 10^6 W/m^2$
$5.6 \times 10^7 W/m^2$
Correct Answer:
$5.6 \times 10^7 W/m^2$
Explanation:
$ 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$