Light from a point source in air falls on a spherical glass surface (refractive index, $\mu=1.5$ and radius…
Solution

$\begin{aligned} & \frac{\mu_2}{\mathrm{v}}-\frac{\mu_1}{\mathrm{u}}=\frac{\mu_2-\mu_1}{\mathrm{R}} \\ & \frac{1.5}{200}-\frac{1}{-\mathrm{x}}=\frac{1.5-1}{50}\end{aligned}$
$\begin{aligned} & \frac{1}{x}=\frac{1}{100}-\frac{3}{400} \\ & x=400 \mathrm{~cm} \\ & x=4 m\end{aligned}$
Asked in: JEE Main 2025 (03 Apr Shift 2)