Question

The number of photons of light having wave number x in 10 J of energy source is

Answer 1

$$\begin{gathered} E=\frac{nhc}{\lambda }=nhc\stackrel{\rightharpoonup }{\nu }(\sin ce\stackrel{\rightharpoonup }{\nu }=\frac{1}{\lambda }) \\ 10=nhc\stackrel{\rightharpoonup }{\nu } \\ n=\frac{10}{hc\stackrel{\rightharpoonup }{\nu }}=\frac{10}{hcx}=\frac{10}{6.626\times {10}^{-34}\times 3\times {10}^8\times x}=\frac{0.5031}{x}\times {10}^{-26} \end{gathered}$$