Question

A light ray from air strikes an unknown medium at angle 60° as shown. If the angle of refraction is 30°. Evaluate the refractive index of the medium.

• A. $\sqrt{2}$
• B. $\sqrt{3}$
• C. $\sqrt{5}$
• D. $\sqrt{7}$

Answer 1

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

Given:
Angle of incidence, $\left(i\right)=60°$
Angle of refraction, $\left(r\right)=30°$

Using snells law,

$n=\frac{sini}{sinr}$

$n=\frac{sin60°}{sin30°}$

$n=\frac{\sqrt{3}}{2}$ $\times \frac{2}{1}$

$n=\sqrt{3}$

𝑛= √3