A ray is incident at an angle of incidence on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is , then the angle of incidence is nearly equal to [2020]
(3)
Light ray emerges normally from another surface, so the angle of emergence (e) = 0.
Using Snell’s law on the first surface,
For small angles,
Hence,