Rule1:-A ray of light which is parallel to the principal axis of a concave mirror, passes through its focus after reflection from the mirror.
Rule4:-A ray of light which is incident at the pole of a concave mirror is reflected back making the same angle with the principal axis.
Rule2:-A ray of light passing through the center of curvature of a concave mirror is reflected back along the same path.
Rule3:-A ray of light passing through the focus of a concave mirror becomes parallel to the principal axis after reflection.
Rule3:-A ray of light passing through the focus of a concave mirror becomes parallel to the principal axis after reflection.
Rule4:-A ray of light which is incident at the pole of a concave mirror is reflected back making the same angle with the principal axis.