What is prism?

Discuss about Nicol prism.

A prism is made of glass of unknown refractive index. A parallel beam of light is incident on a face of the prism. The angle of minimum deviation is measured to be 40^(@) .What is the refrective index of the material of the prism? The refracting angle of the prism is 60^(@) . If the prism is placed in water (refractive index 1.33) , predict the new angle of minimum deviation of a parallel beam of light .

A thin prism having refracting angle 10^@ is made of glass of refractive index 1.42.This prism is combined with another thin prism of glass of refractive index 1.7.This combination produces dispersion without deviation The refacting angle of second prism should be :

The angle of deviation of light ray in a prism depends on the angle of …............. .