Question

A beam of light travelling in air enters into a liquid.
Its speed reduces by 30%. The refractive index of
liquid with respect to air is​

Answer 1

Answer:

Explanation: refractive index = C/v

Answer 2

Given:

A beam of light travelling in air enters into a liquid. Its speed reduces by 30%.

To find:

Refractive index of liquid ?

Calculation:

• Let velocity of light in air be v.

So, velocity in liquid will be :

$\sf \: v_{liquid} = v - 30\%v$

$\sf \implies v_{liquid} = v - \dfrac{30v}{100}$

$\sf \implies v_{liquid} = \dfrac{(100 - 30)v}{100}$

$\sf \implies v_{liquid} =0.7 \: v$

So, refractive index will be:

$\sf \mu = \dfrac{v_{air}}{v_{liquid}}$

$\sf \implies\mu = \dfrac{v}{0.7v}$

$\sf \implies\mu = \dfrac{1}{0.7}$

$\sf \implies\mu = \dfrac{10}{7}$

So, refractive index of liquid is 10/7.