UPSC CDS 2 2020 GK Paper

Lens with power +2.5 D will bend the light rays through the largest angle because a positive sign shows a convex lens, a convex lens concentrates the light rays that are incident on it, so it is called a converging lens. The bending of light rays is maximal at the top and bottom of the convex lens because the top and bottom prisms have the greatest angle between the refracting surfaces.