Question

The speed of light in a transparent medium is 0.6 times that of its speed in vacuum. Find the refractive index of the medium.

Answer 1

Refractive index is defined as

$\mu = \frac{speed of light in air}{speed of light in medium}$

$\mu = \frac{c}{v}$

given that

v = 0.6 c

so we will have

$\mu = \frac{c}{0.6c}$

$\mu = 1.67$

Answer 2

Answer:

The refractive index is 1.66

Explanation:

The speed of light in a transparent medium is 0.6 times that of its speed in vacuum .

Refractive index of medium = speed of light in vacuum / speed of light in medium  

So

RI = 1/0.6 = 5/3 or 1.66