(a) Fig. 7.1 shows a ray of red light incident on a glass prism at point P. The ray of red light is refracted at point P
On Fig. 7.1:
(i) draw the normal at point P
(ii) draw the path of the ray of red light through the glass prism and into the air.
(b) A ray of blue light replaces the ray of red light. The angle of incidence for the blue ray entering the prism is the same as in Fig. 7.1. Describe any difference between the path of the blue ray in the prism and the path of the red ray in the prism.
(c) Another ray enters the glass prism and is totally internally reflected. State two conditions for a ray to be totally internally reflected.
Most-appropriate topic codes (Cambridge IGCSE Physics 0625):
• Topic 3.2.2 — Refraction of light (Parts (a), (b), (c))
