Question

In the figure shown, what is the apparent distance of the bird as seen by the fish ?

• A. $84\text{m}$
• B. $76\text{m}$
• C. $80\text{m}$
• D. $62\text{m}$

Answer 1

The correct option is A $84\text{m}$

Given: height of bird above water $h=36\text{m}$
depth of fish below water $d=36\text{m}$

Here, fish is the observer that means light rays are coming from the bird and falling on the fish's eyes.

So, ${\mu }_1=1;{\mu }_2=4/3.$

So, using formula of apparent height
$\frac{h^{\prime }}{h}=\frac{{\mu }_2}{{\mu }_1}$

$\Rightarrow h^{\prime }=36\times \frac{4}{3}=48\text{m}$

So, apparent distance of bird as seen by the fish $=(36+48)\text{m}=84\text{m}$.

Hence, option $\left(a\right)$ is the correct answer.