Question

relation between angle of deviation and angle of reflection

Answer 1

The angle of deviation through a triangular prism is defined as the angle between the incident ray and the emerging ray (angle δ). It can be shown that when the angle of incidence i is equal to the angle of refraction r' for the emerging ray, theangle of deviation is at a minimum.

Answer 2

d = angle of deviation

i = angle of incidence

e = angle if emergence

A = angle of prism

u = refractive index of the prism's material

Now in general case,

d = i + e - A

but for minimum deviation, we have the condition as i = e, so it becomes,

d = 2i - A

Now if we've a very small angled prism, this goes as:

d = (u - 1)A [ where A is the small angle of the prism ]

Thank you.