Question

The refractive index of glass for light going from air to glass is `3/2`. The refractive index for light going 2 from glass to air will be ______.

Options

• `1/3`

• `4/5`

• `4/6`

• `5/2`

Answer 1

The refractive index of glass for light going from air to glass is `3/2`. The refractive index for light going 2 from glass to air will be `bbunderline(4/6)`.

Explanation:

By the principle of reversibility of light, the refractive index going from glass to air is the exact reciprocal of the refractive index going from air to glass.

Therefore, the reciprocal of `3/2` is `2/3`. 

Multiplying both the numerator and denominator of `2/3` by 2 gives the equivalent fraction.