Question

How will you distinguish between a plane mirror, a concave mirror and a convex mirror, without touching them? 

Answer 1

To distinguish between a plane mirror, concave mirror and convex mirror, the given mirror is held near the face and image is seen. There can be following three cases:

 

Case (i): If the image is upright, of same size and it does not change in size by moving the mirror towards or away from the face, the mirror is plane.

 

(ii) If the image is upright and magnified, and increases in size on moving the mirror away, the mirror is concave.

 

(iii) If the image is upright and diminished and decreases in size on moving the mirror away, the mirror is convex.