Ray Diagrams are used so that we can determine conveniently the positions and sizes of images formed by mirrors. To make a ray diagram we should know the position of the object and the location of the center of curvature. To locate the image, three rays are constructed and these rays start from the same object point.
RAY DIAGRAMS FOR CONCAVE MIRRORS
1. ray 1 is drawn parallel to the principal axis and is reflected back through the focal point(F).
2. ray 2 is drawn through the focal point. thus, it is reflected parallel to the principal axis.
3. ray 3 is drawn through the center of curvature(C) and is reflected back on itself.The intersection of these rays at a point locates the image.
RAY DIAGRAMS FOR CONVEX MIRRORS
1. ray 1 is drawn parallel to the principal axis but light but light will not pass through the mirror and so it is reflected and broken lines are drawn passing through the other focal point.
2.ray 2 is drawn through the focal point but again light will not pass through thus reflected parallel to the principal axis extending a broken line to the other side.
3. ray 3 is drawn passing through the other center of curvature.
The intersection of these rays at a point locates the image.
