A light ray passes from air to denser medium of certain thickness and emerges on the other side. If emergent ray is parallel to the incident ray, the distance travelly by the ray of light in the denser medium is 6 cm, and the angle of incidence and refraction are `60^(@) and 30^(@)` , respectively, find the lateral displacement of the light ray.

Explanation

(i) Angle of deviation d = I - r

In triangle ABC
`(BC)/(AB) = sin d`.
AB is the distance travelled by the light ray inside the denser medium and BC is the lateral shift.
(ii) 3 cm