Question

The speed of light in diamonds is 125,000 km s^-1. What is its refractive index? (speed of light in air = 3 × 10⁸ ms^-1).

Answer 1

Given,

Speed of light in diamond, v = 125 × 10⁶ m/s

Speed of light in air, c = 3 × 10⁸ m/s

Refractive index of diamond, μ D = ?

We know that, 

∴ `mu = c/v` 

∴ µ =`(3xx10^8m//s)/(125xx10^6m//s)`

∴ µ =`(3xx10^2m//s)/125`

∴ µ = `300/125`

∴ µ = 2.4