Question

An object A is placed at a distance 'd' in front of a plane mirror. If one stand s directly behind the object at distance 's' from the mirror, then the distance of the image of A from the individual is

• A. 2s
• B. 2d
• C. s + d
• D. s + 2d

Answer 1

The correct option is C s + d

Answer is C.

The image has the same dimensions as the object and is the same distance behind the mirror as the object is in front of the mirror.
In this case, the object A is placed at a distance d in front of a plane mirror and the person stands right behind the object and the total distance between the person and the mirror is S. This is inclusive of the distance of the object from the mirror.
Therefore, the distance of the image from the individual to the image that is formed at a distance d on the other side is given as S+d.