(i) How far should one hold an object from a concave mirror of focal length 40 cm so as to get a virtual image twice the size of the object?
(ii) For a concave mirror, draw ray diagrams to show the reflected ray in following cases:
(a) A ray incident parallel to its principal axis.
(b) A ray passing through its center of curvature before being incident on mirror.
(c) A ray incident obliquely on pole of mirror.