A ray of light is incident normally on one face of an equilateral glass prism. Consider the following statements regarding the path of the ray: I. The angle of incidence at the second face is 60^ . II. For the ray to emerge from the second face, the refractive index of the prism must be less than or equal to 2 3 . III. If the refractive index of the prism is 1.5 , the ray undergoes total internal reflection at the se

Step-by-step solution

Since the ray is incident normally on the first face, i₁ = 0^ , which means the angle of refraction at the first face r₁ = 0^ . For a prism, r₁ + r₂ = A . For an equilateral prism, A = 60^ . Thus, the angle of incidence at the second face r₂ = 60^ - 0^ = 60^ . (Statement I is correct) For the ray to emerge, r₂ C , where C is the critical angle. (60^ ) C = 1 3 2 1 2 3 1.15 . (Statement II is correct) If = 1.5 , it is greater than 2 3 . Hence, the angle of incidence ( 60^ ) is greater than the critical angle, and the