In order to distinguish between a plane mirror, a concave mirror and a convex mirror, the given mirror is held near the face and the image obtained is seen.
There can be the following three cases —
- Case 1 — If image is upright, of same size and it does not change in size by moving the mirror towards or away from the face, then the mirror is plane.
- Case 2 — If image is upright, magnified and increases in size on small movement of the mirror away from the face then the mirror is concave.
- Case 3 — If image is upright, dimished and decreases in size on small movement of the mirror away from the face then the mirror is convex.