Question

A circular beam of diameter 2cm falls on a plane surface of glass. The angle of incidence is ${60}^{\circ }$ and $\mu =\frac{3}{2}$ for the glass. The diameter of the refracted beam is

• A. 4 cm
• B. 3 cm
• C. 3.26 cm
• D. 2.52 cm

Answer 1

The correct option is C 3.26 cm

$\mu =\frac{sini}{sinr}=\frac{sin{60}^{\circ }}{sinr}\frac{3}{2}=\frac{\sqrt{3}}{2}\left[\frac{1}{sinr}\right];sinr=\frac{1}{\sqrt{3}}cosr=\frac{\sqrt{2}}{\sqrt{3}}{d}_2=d_1\left[\frac{cosr}{cosi}\right]=d_1\left[\frac{cosr}{cos60}\right]=2\left[\frac{\sqrt{2}}{\sqrt{3}\frac{1}{2}}\right]=4\frac{\sqrt{2}}{\sqrt{3}}=\frac{4\times 1.414}{1.732}d=3.26cm$