Question

What can you say about the nature and position of the image formed by a concave mirror when the object is at its centre of curvature?

Answer 1

Object at the Centre of Curvature:

1. The above Fig. shows object PQ placed at the centre of curvature C.
2. Ray 1 is an incident ray parallel to the principal axis; the reflected ray 1' passes through the focus F.
3. Incident ray 2 passes through the focus, therefore, the reflected ray 2' is parallel to the principal axis.
4. The two reflected rays I' and 2' meet at Q'. P'Q' is the image of the object PQ.
5. It is clear from Fig. that the image is inverted, of the same size as the object and is also located at C.

Hence, the Nature of the image is real and inverted and the position of the image is also at the Centre of curvature.