The powers of two light sources $S_1$ and $S_2$ are in the ratio 2: 1. Source $S_1$ emits $2 \times 10^{15}$ photons per second at a wavelength of 600 nm . Find the number of photons per second emitted at a wavelength of 300 nm by $S_2$. (Shift - II Memory based)

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YESPYQ · Accepted Answer

Correct answer: c) $5 \times 10^{14}$. \begin{equation} \begin{aligned} & \mathrm{P}_1=\mathrm{P}=\frac{\mathrm{N}_1 \mathrm{hc}}{\lambda_1} \quad \mathrm{P}=\frac{\mathrm{Nhc}}{\lambda} \ & \mathrm{P}_2=\frac{\mathrm{P}}{2}=\frac{\mathrm{N}_2 \mathrm{hc}}{\lambda_2} \ & \frac{\mathrm{P}_1}{\mathrm{P}_2}=\frac{\mathrm{N}_1}{\lambda_1} \cdot \frac{\lambda_2}{\mathrm{~N}_2} \ & \mathrm{~N}_2=\frac{\mathrm{N}_1 \lambda_2}{\lambda_1 2}=\frac{2 \times 10^{15} \times 300}{600 \times 2} \ & \mathrm{n}_2=5 \times 10^{14} \text { per second } \end{aligned} \end{equation}

The powers of two light sources \(S_1\) and \(S_2\) are in the ratio 2: 1. Source \(S_1\) emits \(2 \times 10^{15}\) pho…

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