An object is placed at the following distances from a concave mirror of focal length 15 cm.
(i) 10 cm (ii) 20 cm (iii) 30 cm (iv) 40 cm
Which position of the object will produce
(a) Virtual image (b) A diminished real image
(c) An enlarged real image (d) An image of same size.
Concave mirror forms virtual image if object is placed between the focus and pole of the mirror. Therefore, for the position of object at 10 cm mirror forms the required image.
A real and diminished image is formed when object lies beyond C i.e., beyond 2F. So, for the position of object at 40 cm, mirror forms the required image.
An enlarged real image is formed when object lies between F and 2 F. So, for the position of object at 20 cm, mirror forms the required image.
An image of same size of the object is formed when object lies at C or 2F. So, for the position of object at 30 cm, mirror forms the required image.