Mention the relation between the real depth and the apparent depth in terms of the refractive indices of the media.

(N/A) When an object is placed in a denser medium of refractive index $\mu_2$ and viewed from a rarer medium of refractive index $\mu_1$,the light rays originating from the object undergo refraction at the interface.
According to Snell's law and the geometry of refraction,the relation between real depth $(d)$ and apparent depth $(d')$ is given by:
$d' = d \times \frac{\mu_1}{\mu_2}$
Where:
$d$ = Real depth of the object.
$d'$ = Apparent depth of the object.
$\mu_1$ = Refractive index of the medium from which the observer is viewing (e.g.,air,$\mu_1 \approx 1$).
$\mu_2$ = Refractive index of the medium in which the object is placed.