Question

6. When a ray of light enters a medium of refractive
index u, it is observed that the angle of refraction
is half of the angle of incidence is than angle of
incidence is
(1) 2 cos'(u/2)
(2) cos(u/2)
(3) 2 cos(u)
(4) 2 sin-'(u/2)​

Answer 1

angle of incidence i =2cos-1u/2

Explanation:

solution is given in pic.