Question

A boy is observing his image in a plane mirror. The distance between the mirror and his image is 6 $m$. If he moves 2 $m$ towards the mirror, then the distance between the boy and his image will be:

• A. 8 $m$
• B. 6 $m$
• C. 4 $m$
• D. 2 $m$

Answer 1

The correct option is A

8 $m$

Initially, the boy is at B1. In a plane mirror, the image is the same distance behind the mirror as the object is in front of the mirror. Hence, B1 is at a distance of 6 $m$ from the mirror. When he moves 2 $m$ towards the mirror, he moves to B2. the image will shift to the position B2' as shown in the figure. Now the distance from the mirror to B2 is 4 $m$ and the distance from the mirror to B2' is 4 $m$.
Hence, the distance between the boy and his image becomes equal to 8 $m$, as evident from the figure below.