Question

A glass slab ($\mu =1.5)$ of thickness $4\text{cm}$ is pressed against newspaper, the distance by which letter of the paper are seen raised against the paper by someone who is looking at letters along normal to the slab is

• A. $\frac{2}{3}\text{cm}$
• B. $1\text{cm}$
• C. $\frac{4}{3}\text{cm}$
• D. $\frac{8}{3}\text{cm}$

Answer 1

The correct option is C $\frac{4}{3}\text{cm}$


From the diagram, we can see that

Shift of letters $\left(d\right)=h-h^{\prime }$

Now using formula of apparent depth,

$\therefore d=h-\frac{h}{\mu }=4-\frac{4}{1.5}=\frac{4}{3}\text{cm}$

Hence, option $\left(c\right)$ is correct.