Q. A man is $180cm$ tall and his eyes are $10cm$ below the top of his head. In order to see his entire height right from toe to head, he uses a plane mirror kept at a distance of $1m$ from him. The minimum length of the plane mirror required is
A) 180$cm$
B) 90$cm$
C) 85$cm$
D) 170$cm$
Explanation
(b) According to the following ray diagram length of mirror
$= \frac{1}{2}(10 + 170) = 90cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.