A ray of light going thrh a prism of prism angle 60,is found to deviate at least by 30.what is range of refractive index of the prism{ans___

angle of minimum deviation = d & angle of prism =A then

n(refractive index) = sin(A+d)/2 /sin(A/2)

                           =sin45/sin30

                           =2^1/2