Rankers Physics

Uncategorized: Practice Problem & Solution

Assuming the sun to have a spherical outer surface of radius $r$, radiating like a black body at temperature $t^{\circ}\text{C}$, the power received by a unit surface, (normal to the incident rays) at a distance $R$ from the center of the sun is where $\sigma$ is the Stefan's constant: (2007)
$\frac{r^2\sigma(t + 273)^4}{4\pi R^2}$
$\frac{16\pi^2 r^2 \sigma t^4}{R^2}$
$\frac{r^2\sigma(t + 273)^4}{R^2}$
$\frac{4\pi r^2 \sigma t^4}{R^2}$

Solution Explained:

To solve this problem, we apply the core principles of Uncategorized. Understanding the underlying formula is key to arriving at the correct answer below:

Power received by a unit surface is Intensity $I = \frac{\sigma (4\pi r^2) T^4}{4\pi R^2} = \frac{\sigma r^2 (t+273)^4}{R^2}$.

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