Question

A small air bubble is inside a transparent cube of side length $24cm$ and of refractive index $\frac{4}{3}$. If the apparent distance of air bubble from a face is $9cm$ then its apparent distance from opposite face is :

• A. $6cm$
• B. $8cm$
• C. $9cm$
• D. $12cm$

Answer 1

Answer: (C)

$9cm$

We know that (Real depth) / (Apparent depth) $=\mu$

Now, According to question,

$\frac{realdepth}{9}=\frac{4}{3}$

$\Rightarrow$ real depth $=$ 12cm.

Which implies that the air bubble is in the middle of the cube. so, from the other side also the real depth is 12cm. so, the apparent distance from the other end is also 9cm.