A thin convex lens is used to form images of objects placed at various distances along its principal axis.
(i) Define linear magnification produced by a lens.
(ii) For a convex lens, explain with reason the sign and magnitude of magnification when the object is placed: (a) between the optical centre and the principal focus F, (b) at 2F, and (c) beyond 2F. Support your answer with the appropriate mathematical relation.
(iii) Draw neatly labelled ray diagrams for cases (a) and (c) to illustrate your explanation.