(i) Rohit claims to have obtained an image twice the size of the object with a concave lens. Is he correct? Give reason for your answer.
(ii) Where should an object be placed in case of a convex lens to form an image of same size as of the object? Show with the help of ray diagram, the position and nature of image formed?
(iii) With the help of ray diagram, illustrate the change in position, size and nature of image formed if convex lens in case of (ii) is replaced by a concave lens of same focal length.

Explanation

(i) Rohit's claim is not correct. This is because image formed by a concave lens is always smaller in size than the object.
(ii) To form an image of size as the object, the object has to be placed at a distance `=2f` from the lens. The course of rays is as shown in Fig.

(iii) In (ii) above, when a convex lens is replaced by a concave lens of same focal length, image formed is smaller in size than the object as