Question

Use Snell's law to find the refractive index of an interface when the angle of incidence is ${60}^{\circ }$ and the angle of refraction is ${30}^{\circ }$.

• A. $\sqrt{3}$
• B. $3$
• C. $\sqrt{2}$
• D. $2$

Answer 1

The correct option is A $\sqrt{3}$


Refractive index, $n=\frac{sini}{sinr}$

Given angle of incidence, $i={60}^{\circ }.$

Given angle of incidence, $r={30}^{\circ }$

Also, we have $sin{60}^{\circ }=\frac{\sqrt{3}}{2}$ and $sin{30}^{\circ }=\frac{1}{2}$

Putting the value in the formula of refractive index, we will get,

Refractive index(n)$=\frac{sin{60}^{\circ }}{sin{30}^{\circ }}=\frac{\sqrt{3}}{2}\times \frac{2}{1}=\sqrt{3}$