Question

A ray of green light enters a liquid from air, as shown in Fig. 4.21. The angle 1 is ${45}^{\circ }$ and angle 2 is ${30}^{\circ }$.

(a) Find the refractive index of the liquid.

(b) Show in the diagram the path of the ray after it strikes the mirror and re-enters in the air. Mark in the diagram the angles wherever necessary.

(c) Redraw the diagram if the plane mirror becomes normal to the refracted ray inside the liquid. State the principle used.

Answer 1

(b)

(c)

Here, the principle of reversibility is used.