Question

Consider the situation shown in Fig. Water $(\mu =4/3)$ is filled in a beaker upto a height of $10cm$.
A plane mirror is fixed at a height of $5cm$ 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. $15cm$
• B. $12.5cm$
• C. $7.5cm$
• D. $10cm$

Answer 1

The correct option is B $12.5cm$

As seen from out side shift observed due to water is $t\times (1-\frac{1}{\mu })=10\times (1-\frac{3}{4})=2.5$

and for the mirror object distance is $5+10-2.5=12.5$

Hence the image distance from mirror is $12.5$, Hence option $B$ is correct .