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Question
The speed of yellow light in a certain liquid is 2.4 × 108 m s−1. Find the refractive index of the liquid.
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Solution
Given
Speed of yellow light in liquid (vL)= 2⋅4 × 108 m s−1
And speed of yellow light in air speed = va
Let μL 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.
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