Question

Velocity of light in glass whose refractive index with respect to air is 1.5 is $2\times {10}^8{ms}^{-1}$ and in certain liquid the velocity of light found to be $2.5\times {10}^8{ms}^{-1}$ .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

Given Data:
Refractive index of glass, $\mu =1.5$

Velocity of light in glass,$v_g=$ $2\times {10}^8{ms}^{-1}$

Velocity of light in liquid, $v_l=$ $2.5\times {10}^8{ms}^{-1}$

Step 1: Refractive index of liquid with respect to air:

AAs we know refractive index is inversely proportional to velocity, so,

${\mu }_l=\frac{v_a}{v_l}=\frac{c}{v_l}=\frac{3\times {10}^8}{2.5\times {10}^8}=1.2$

The refractive index of the liquid with respect to air is: 1.2