Physics - Geometrical Optics Question with Solution | TestHub

The apparent depth of water in cylindrical water tank of diameter $2R\mathrm{cm}$ is reducing at the rate of $x\mathrm{cm}/$ minute when water is being drained out at a constant rate. The amount of water drained in c.c. per minute is ( $n_1=$ refractive index of air, $n_2=$ refractive index of water).