Question

The refractive index of media A, B, C, and D are 1.44, 1.47, 1.83, and 1.33 respectively. In which of these will the light travel a. fastest?

Answer 1

1. The refractive index $\left(\mu \right)$ of a medium is defined as the ratio of the speed of light in air $\left(c\right)$ to the speed of light in that medium $\left(v\right)$.

Mathematically, $$\begin{gathered} \mu =\frac{c}{v} \\ Orv=\frac{c}{\mu } \end{gathered}$$

2. Light travels faster in a medium having a lower refractive index.

3. Among given media, medium D has the lowest refractive index hence light will travel fastest in medium D.