Question

Velocity of light in glass whose refractive index with respect to air is 1.5 is $2\times {10}^{8}m{s}^{-1}$ and in certain liquid the velocity of light found to be $2.50\times {10}^{8}m{s}^{-1}$.The refractive index of the liquid
with respect to air is

• A. 0.64
• B. 0.8
• C. 1.2
• D. 1.44

Answer 1

The correct option is C 1.2

Refractice index of glass slab $=1.5$
Velocity of light in glass $=2\times {10}^{8}m{s}^{-1}$
Velocity of light in liquid $=2.50\times {10}^{8}m{s}^{-1}$
$\mu \alpha \frac{1}{v}\Rightarrow \frac{{\mu }_{li}}{{\mu }_g}=\frac{v_g}{v_l}\Rightarrow \frac{{\mu }_l}{1.5}=\frac{2\times {10}^8}{2.5\times {10}^8}$
$\Rightarrow {\mu }_l=1.2$