Question

The depth of a pond is 10m what is the apparent depth for a person looking normally to the water surface (water=4/3)

Answer 1

μ=real depth/apparent depth
4/3=10/AD
AD=10x3/4
AD=7.5m

Answer 2

The apparent depth is 7.5 m

Given:

Refractive index (µ) = 4/3

Real depth = 10 m

To find:

Apparent depth = AD = ?

Solution:

As we all know,

$\text { Refractive index} =\frac{\text {Real depth}}{\text {Apparent depth}}$

The apparent depth refers to the depth of the material from a transparent medium. The objects appears closer in the apparent depth than the real depth.  

$\mu=\frac{\text {Real depth}}{A D}$

$\frac{4}{3}=\frac{10}{A D}$

$A D=10 \times \frac{3}{4}$

$AD = 7.5 \ m$