Question

A transparent medium shows relation between i and r as shown. If the speed of light in vacuum is c the Brewster angle for the medium is

• A. $60^{\circ }$
• B. $30^{\circ }$
• C. $90^{\circ }$
• D. $45^{\circ }$

Answer 1

Answer: (A)

$ByBrewster’slaw,n=tan{\theta }_p$
$Alson=\frac{sini}{sinr}$
$But\frac{sini}{sinr}=\frac{1}{slope}ofgivengraph$
$\frac{sini}{sinr}=\frac{1}{tan30^{\circ }}=\frac{1}{\frac{1}{\sqrt{3}}}=\sqrt{3}$
$\therefore tan{Q}_p=n=\sqrt{3}$
$Q_p=ta{n}^{-1}\left(\sqrt{3}\right)=60^{\circ }$