Question

Given that, the velocity of light in quartz = $1.5\times 10^{8}ms^{- 1}$ and velocity of light in glycerine = $\frac{9}{4}\times 10^{8}ms^{- 1}$ . If a slab made of quartz is placed in front of an object kept in glycerine (as shown in the figure), then the shift of the object produced by slab is

• A. $6cm$
• B. $3.55cm$
• C. $9cm$
• D. $2cm$

Answer 1

Answer: (A)

$n =\frac{\text { velocity of light in vaccum }}{\text { velocity of light in medium }}$
velocity of light in vacuum $=3 \times 10^{8} m s ^{-1}$
$n _{\text {quartz }}=2 ; n _{\text {glycerine }}=\frac{4}{3} \Rightarrow \frac{ n _{\text {quartz }}}{ n _{\text {gliccrinc }}}=\frac{2}{4 / 3}=\frac{3}{2}=\mu_{ rel }$
shift $= t \left(1-\frac{1}{\mu_{ rel }}\right)=18\left(-\frac{1}{3 / 2}\right)=6 cm$