Question

A concave mirror of radius R is kept on a horizontal table. Water (refractive index $=\mu$) is poured into it up to a height h. Where should an object be placed so that its image is formed on itself ?

Answer 1

Let the object be placed at a height 'x' above the surface Of the water. The apparent position of the object with respect to mirror should be at the centre of curvature so:that the image ie formed at the same position.

Since, $\frac{\text{Real depth}}{\text{Apparent depth}}=\frac{1}{\mu }$

(with respect to mirror)

Now, $\frac{x}{R-h}=\frac{1}{\mu }$

$\Rightarrow x=\frac{R-h}{\mu }$