Question

For the arrangement of object and observer on the opposite sides of a combination of glass slabs, the total shift of object 'O' as observed by observer O' is:

• A. 20 cm
• B. 30 cm
• C. 15 cm
• D. 25 cm

Answer 1

The correct option is C 15 cm

Net shift produced is the sum of shifts produced by each glass slab.
$S^{}net=S_1+S_2+S_3$
$\Rightarrow S_{net}=t_1(1-\frac{1}{{\mu }_1})+t_2(1-\frac{1}{{\mu }_2})+t_3(1-\frac{1}{{\mu }_3})$
$\Rightarrow S_{net}=10(1-\frac{1}{2})+15(1-\frac{2}{3})+10(1-\frac{1}{2})$
$\therefore S_{net}=5+5+5=15cm$

Why this question? It intends to test your understanding of net shift produced by combination of slabs.