Physics - Geometrical Optics Question with Solution | TestHub

Let the height of the water filled in the container be $h$.

The refractive index of water is $\mu =\frac{4}{3}$.

The apparent depth of the water is given by $h_{app}=\frac{h}{\mu }$.

According to the given condition, the apparent depth is half the actual height of the container.

Actual height of the container $=30\text{ cm}$.

Therefore, $h_{app}=\frac{30}{2}=15\text{ cm}$.

Equating the two expressions for apparent depth:

$\frac{h}{4/3}=15$

$h=15\times \frac{4}{3}=20\text{ cm}$

Answer: 20 cm