Question

The speed of yellow light in a certain liquid is 2⋅4 × 10⁸ m s⁻¹. Find the refractive index of the liquid.

Answer 1

Given:
Speed of yellow light in liquid (v_L)= 2⋅4 × 10⁸ m s⁻¹
And speed of yellow light in air speed = v_a
Let μ_L be the refractive index of the liquid
Using, ${\mathrm{\mu }}_{\mathrm{L}}=\frac{\mathrm{speed}\mathrm{of}\mathrm{light}\mathrm{in}\mathrm{vaccum}}{\mathrm{velocity}\mathrm{of}\mathrm{light}\mathrm{in}\mathrm{the}\mathrm{given}\mathrm{medium}}=\frac{c}{v_{\mathrm{L}}}$
${\mathrm{\mu }}_{\mathrm{L}}=\frac{3\times {10}^8}{\left(2.4\right)\times {10}^8}=1.25$

Hence, the required refractive index is 1.25.