Question

The velocity of light in air is \(3 \times 10^{8} \mathrm{~ms}^{-1}\) and in glass is \(2 \times 10^{8} \mathrm{~ms}^{-1}\). Find the refractive index of glass.

Answer 1

\[ \text{Refractive index of glass} = \frac{\text{Speed of light in air}}{\text{Speed of light in glass}} \]

\[= \frac{3 \times 10^{8}}{2 \times 10^{8}}\]

= 1.5

Therefore, the refractive index of glass is 1.5. Refractive index has no unit.