Reflection Of Light

FORMATION OF DIFFERENT TYPES OF IMAGES BY A CONCAVE MIRROR IN DIFFERENT POSITIONS OF THE OBJECT:

The type of image formed by a concave mirror primarily depends on the position of the object in front of the mirror. When an object is moved closer to the mirror, starting from infinity, the following six cases arise:

(i) When the object is at infinity
When the object is at infinity, the rays of light starting from the object on travelling such a large distance are assumed to become parallel to each other while falling on the mirror. These parallel rays of light may fall on the mirror in the following two ways.
        

In the above two cases image is formed at the focus of the mirror. Therefore we can say that when the object is at infinity. The image is:
(a) Formed at the focus ‘F’ of the mirror.(b) Real and inverted.(c) Highly diminished, point sized.

(ii) When the object is beyond the centre of curvature ‘C’ of concave mirror
When the object is placed beyond the centre of curvature ‘C’ of the concave mirror, the image is
(a) Formed between the Focus ‘F’ and the centre of curvature ‘C’ of the concave mirror.(b) Real and inverted.c) Smaller in size and diminished.
                                

(iii) When the object is at the centre of curvature of concave mirror
When the object is placed at the centre of curvature of concave mirror. The image is
(a) Formed at the centre of curvature ‘C’ of the concave mirror.
(b) Real and inverted.
(c) Of the same size as that of the object.