From the graph of angle of deviation versus angle of incidence for an equilateral prism, the refractive index of material of prism is

Step-by-step solution

For an equilateral prism, the angle of the prism is A = 60^ . From the given graph of angle of deviation ( ) versus angle of incidence ( i ), the minimum angle of deviation is _m = 60^ which occurs at i = 60^ . The refractive index ( ) of the material of the prism is given by the formula: = ( A + _m 2 ) ( A 2 ) Substituting the values of A and _m : = ( 60^ + 60^ 2 ) ( 60^ 2 ) = (60^ ) (30^ ) = 3 2 1 2 = 3 Answer: 3