Question

When a light rays enters a medium with refractive index $n_2$ from a medium with refractive index $n_1$ at curved interface with radius of curvature $R$ is given by
$\frac{n_2}{V}-\frac{n_1}{U}=\frac{n_2-n_1}{R}$
Now assume that the surface is plane and rewrite the formula with suitable changes.

Answer 1

Formula is given as $\frac{n_2}{v}-\frac{n_1}{u}=\frac{n_2-n_1}{R}$

For plane surface $R=\infty$

Or $\frac{n_2}{v}-\frac{n_1}{u}=\frac{n_2-n_1}{\infty }$

$⟹$ $\frac{n_2}{v}-\frac{n_1}{u}=0$

We get $v=\frac{n_2}{n_1}u$