Question

How many photons does the sun emits per second?

Answer 1

Given intensity $I=1.4\times {10}^{3}W/m^2$ and wavelength of light $\lambda$=5$\times {10}^{-7}m$

We know $n=\frac{intensity\times \lambda }{hc}$ where h= planks constant=6.63$\times$${10}^{-34}$ and C=speed of light in air =3$\times {10}^8$.

Now putting he above mentioned values in the provided equation we get,

$n=\frac{1.4\times {10}^3\times 5\times {10}^{-7}}{6.63\times {10}^{-34}\times 3{\times 10}^8}=3.5\times {10}^{21}$