Question

ii) The speed of light reduced to 0.5 times when it enters from air to another medium. Find the refractive index of medium​

Answer 1

Given:

The speed of light reduced to 0.5 times when it enters from air to another medium.

To find:

Refractive index of medium ?

Calculation:

• Let velocity of light in air be v , then velocity of light in that medium will be 0.5 × v = v/2.

• Let refractive index be $\mu$

Now, we know that :

$\mu = \dfrac{velocity \: in \: air}{velocity \: in \: medium}$

$\implies \mu = \dfrac{v}{( \dfrac{v}{2}) }$

$\implies \mu = 2$

So, refractive index of medium is 2.

• Please note that refractive index does not have any unit because it is a ratio of similar quantities.