QJEEM25Ph6240: JEE Main 2025 Physics - Class 12 JEEM25Ph6240 Solution: The ratio of the power of a light source to that the light…

$\begin{aligned}&\text { Since power emitting by a source is given as }\\&\begin{aligned}& =\frac{\text { Total energy emitted }}{\text { time }} \\& =\frac{\left(E_1 \text { photon }\right) \times \text { Number of photons }(N)}{t} \\& P_1=\left(E_1\right) n\end{aligned}\end{aligned}$

$\begin{aligned}&\begin{aligned}& \frac{\mathrm{P}_1}{\mathrm{P}_2}=\frac{\left(\mathrm{E}_1\right) \mathrm{n}_1}{\left(\mathrm{E}_2\right) \mathrm{n}_2}=\frac{\left(\frac{\mathrm{hC}}{\lambda_1}\right) \mathrm{n}_1}{\left(\frac{\mathrm{hC}}{\lambda_2}\right) \mathrm{n}_2} \\& \frac{\mathrm{P}_1}{\mathrm{P}_2}=\left(\frac{\lambda_2}{\lambda_1}\right) \frac{\mathrm{n}_1}{\mathrm{n}_2}\end{aligned}\\&\text { Substituting the given values }\\&\begin{aligned}& 2=\left(\frac{300}{600}\right) \times \frac{2 \times 10^{15}}{\mathrm{n}_2} \\& \mathrm{n}_2=\frac{1}{2} \times 10^{15}=5 \times 10^{14} \text { Photon } / \mathrm{sec}\end{aligned}\end{aligned}$