Draw suitable rays by which we can guess the position of the image formed by a concave mirror. (AS5)

There are principal rays which help guessing the position of image. With the help of two principal rays we can guess the position of image as the reflected rays meet at the point of image formation. Those principal rays are:

• A ray parallel to the principal axis , after reflection, passes through the focus.

• A ray incident towards or away from the centre of curvature is reflected back along its original path.

• A ray incident at pole at an angle i is reflected at an angle i.

• A ray through the focus is reflected parallel to the axis.