To construct a ray diagram we use two rays of light which are so chosen that it is easy to determine their directions after reflection from the mirror. Choose these two rays and state the path of these rays after reflection from a concave mirror. Use these two rays to find the nature and position of the image of an object placed at a distance of 15 cm from a concave mirror of focal length 10 cm.

The two rays of light that are commonly used to construct a ray diagram for a concave mirror are:

(i) A ray parallel to the principal axis, which passes through the principal focus after reflection.

(ii) A ray passing through the principal focus, which emerges parallel to the principal axis after reflection.

Using these two rays, we can determine the nature and position of the image of an object placed at a distance of 15 cm from a concave mirror of focal length 10 cm.

Since the object is placed between the focal point and the centre of curvature, the image will be real, inverted, and magnified. The image will be formed at a distance of 30 cm from the mirror.