The two rays chosen to construct a ray diagram are shown in the ray diagram given below.
(i) Ray I: When the incident ray is parallel to the principal axis, the reflected ray will pass through the focus of concave mirror.
(ii) Ray II: When the incident ray passes through or appears to pass through the centre of curvature, the light, after reflection from the spherical mirror, reflects back along the same path.
The image formed is real, inverted and magnified. It is formed beyond the centre of curvature.