Total Internal Reflection

PQ and PR are two light rays emerging from the object as shown in the figure below:

(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(ii) Copy the ray diagram and complete it to show the position of the image of the object P when seen obliquely from above.
(iii) Name the phenomenon that occurs if the angle of incidence ∠PQN is increased still further.

Observe the given figure and write appropriate phenomenon of light in the box.

If a ray of light passes from medium I to medium II without any change of direction, what can be said about the refractive indices of these media (angle I is not 0)?

Prove the statement.

A rainbow is the combined effect of the refraction, dispersion, and total internal reflection of light.

Answer the following question.

Under what conditions are total internal reflection possible? Explain it with a suitable example.

The adjacent diagram shows two right-angled isosceles prisms A and B. Complete the diagram to show the path of rays P and Q emerging out of the prism B. What principles have you used to complete the diagram?

A spherical marble, of refractive index 1.5 and curvature 1.5 cm, contains a tiny air bubble at its centre. Where will it appear when seen from outside?

Observe the given figure of the raindrop and answer the following questions:

1. Label A and B of the given diagram. Why colour will deviate most.
2. Name the phenomenon shown in label C.