Refractive Index of Prism using the angle of minimum deviation
Example: If the angle of minimum deviation produced by an equilateral prism is 30∘ , then find the refractive index of material of prism.
Solution: given, A=60∘
Minimum angle of deviation for a prism
At the minimum deviation Dm, the refracted ray inside the prism becomes parallel to its base. i.e i=e⇒r1=r2=r Then r=2A and Dm=2i−A where i is the angle of incidence, e is the angle of emergence. r1,r2 are the angles of refraction and A is the angle of the prism.