A right-angled thin prism of angle 6^ and refractive index 1.5 is completely immersed in a transparent liquid of refractive index 1.2 . A light ray is incident normally on the vertical face of the prism. The angle of emergence of the ray into the liquid from the inclined face is

Step-by-step solution

Since the light ray is incident normally on the vertical face, the angle of incidence i₁ = 0^ , which means the angle of refraction r₁ = 0^ . The angle of the prism is A = r₁ + r₂ , so the angle of incidence at the second (inclined) face is r₂ = A = 6^ . Applying Snell's law at the second interface (from prism to liquid) and using the small angle approximation: _ P r₂ = _ L e _ P A = _ L e Substituting the given values ( _ P = 1.5 , _ L = 1.2 , A = 6^ ): 1.5 6^ = 1.2 e e = 1.5 1.2 6^ = 1.25 6^ = 7.5^ Answer: 7.5^