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,

\[\mu_L  = \frac{\text{speed of light in vaccum}}{\text{velocity of light in the given medium}} = \frac{c}{v_L}\]

\[\mu_L  = \frac{3 \times {10}^8}{\left( 2 . 4 \right) \times {10}^8} = 1 . 25\]

Hence, the required refractive index is 1.25.