Q. Consider the situation shown in figure. Water $\left( \mu_{w} = \frac{4}{3} \right)$ is filled in a beaker upto a height of $10\ cm$. A plane mirror fixed at a height of $5\ cm$ from the surface of water. Distance of image from the mirror after reflection from it of an object $O$ at the bottom of the beaker is
A) 15 $cm$
B) 12.5 $cm$
C) 7.5 $cm$
D) 10 $cm$
Explanation
(b) From figure it is clear object appears to be raised by $\frac{10}{4}cm\ (2.5\ cm)$
Hence distance between mirror and
$O^{''''''''} = 5 + 7.5 = 12.5\ cm$
So final image will be formed at 12.5 $cm$ behind the plane mirror
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.