CBSE Class 10 Science 2017 · Paper 531/2 · Question 14

(i) The ray, parallel to the principal axis, falls on a convex lens. After refraction it bends towards the axis and passes through the principal focus F on the other side of the lens ($F_2$). (ii) The ray passes through the principal focus F on the side of the incident light ($F_1$) and falls on a convex lens. After refraction it emerges parallel to the principal axis. (iii) The ray, parallel to the principal axis, falls on a concave lens. After refraction it bends away from the axis, so that it appears to diverge from the principal focus F on the same side as the incident light ($F_1$); this backward extension is drawn dashed. (The three completed ray diagrams are shown.)