Question

If the critical angle for a diamond is $25°$, what is the refractive index of the diamond?

Answer 1

Step 1: Given data

Critical angle, ${\theta }_c=25°$

Refractive index, $\mu =?$

Step 2: Calculating the refractive index

$$\begin{gathered} \mu =\frac{1}{Sin{\theta }_c}=\frac{1}{\sin 25°} \\ \mu =\frac{1}{0.422}=2.36 \end{gathered}$$

Hence, the refractive index of a diamond is $2.36$.