A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will (a) Become zero (b) Become infinite (c) Become small, but non-zero (d) Remain unchanged
Option B is correct answer. When refractive index of lens is equal to the refractive index of liquid, the lens behave like a plane surface with focal length infinity.
