Question

Power produced by a star is 4 x 10²⁸ W. If the average wavelength of the emitted radiations is considered to be 4500 A°, find the number of photons emitted in 1 s.

Answer 1

Answer:

No of photon emitted is 1*10^41

Answer 2

Answer:

$9.05\times 10^{47}$

Explanation:

Given,

$\textrm{Power\ produced\ by\ star,P\ }=\ 4\times 10^{28}\ W$

Energy produced by star, E = power x time

                                      $=> E\ =\ 4\times 10^{28}\times 1\ J$

                                        $=>\ E\ =\ 4\times 10^{28}\ J$

Wavelength of radiation,

$\lambda\ =\ 4500\ A^o$

             $=\ 4500\times\ 10^{-10}\ m$

              $=\ 4.5\times 10^{-7}\ m$

According to formula,

$E\ =\ \dfrac{n.h.c}{\lambda}$

$=>\ 4\times 10^{28}\ =\ \dfrac{n\times 6.626\times 10^{-34}\times 3\times 10^{8}}{4.5\times 10{-7}}$

$=>\ n\ =\ 9.05\times 10^{47}$

Hence, the number of photon emitted in one second is $9.05\times 10^{47}$