Q.31

(i) Explain why the refractive index of any material with respect to air is always greater 1.
(ii) In the figure below a light ray travels from air into the semi-circular plastic block. Give a reason why the ray does not deviate at the semi-circular boundary of the plastic block.

(iii) Complete the ray diagram of the above scenario when the light ray comes out of the plastic block from the top flat end.