Physics - Wave Optics Question with Solution | TestHub

Since power emitting by a source is given as $\begin{array}{rl}& =\frac{\text{ Total energy emitted }}{\text{ time }}\\ & =\frac{\left(E_1\text{ photon }\right)\times \text{ Number of photons }(N)}{t}\\ & P_1=\left(E_1\right)n\end{array}$ $\begin{array}{rl}& \frac{{\mathrm{P}}_1}{{\mathrm{P}}_2}=\frac{\left({\mathrm{E}}_1\right){\mathrm{n}}_1}{\left({\mathrm{E}}_2\right){\mathrm{n}}_2}=\frac{\left(\frac{\mathrm{hC}}{{\lambda }_1}\right){\mathrm{n}}_1}{\left(\frac{\mathrm{hC}}{{\lambda }_2}\right){\mathrm{n}}_2}\\ & \frac{{\mathrm{P}}_1}{{\mathrm{P}}_2}=\left(\frac{{\lambda }_2}{{\lambda }_1}\right)\frac{{\mathrm{n}}_1}{{\mathrm{n}}_2}\end{array}$ Substituting the given values $\begin{array}{rl}& 2=\left(\frac{300}{600}\right)\times \frac{2\times 10^{15}}{{\mathrm{n}}_2}\\ & {\mathrm{n}}_2=\frac{1}{2}\times 10^{15}=5\times 10^{14}\text{ Photon }/\sec \end{array}$