Physics - Geometrical Optics Question with Solution | TestHub

The hollow glass cell is biconcave in shape, so it diverges light when the material inside is optically denser than the medium outside: $\frac{{\mu }_{in}}{{\mu }_{out}}>1$. Filling it with ${\mathrm{CS}}_2(\mu =1.6)$ and immersing it in water $(\mu =1.3)$ gives 1.6/1.3 > 1, so the biconcave shape diverges a parallel beam. Hence (D).