Question

A concave mirror of radius of curvature $h$ is placed at the bottom of a tank containing a liquid of refractive index $\mu$ upto a depth $d$. An object $P$ is placed at height h above the bottom of the mirror. Outside the liquid, an observer $O$ views the object and its image in the mirror. The apparent distance between these two will be

• A. $h(1-\frac{1}{\mu })$
• B. $\frac{2h}{\mu -1}$
• C. zero
• D. $\frac{2h}{\mu }$

Answer 1

Answer: (C)

zero

$u=-h$ ; $f=-\frac{h}{2}$

$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

$\frac{1}{v}+\frac{-1}{h}=\frac{-2}{h}$

$v=-h$

So image and the object coincide

Hence for an observer the apparent distance between these two is $0$

option $C$ is correct