Question

The wavelength of light in two liquids $x$ and $y$ are $3500\, \mathring{A} $ and $7000\,\mathring{A} $ , then the critical angle of $x$ relative toy will be

• A. $ 60^{\circ} $
• B. $ 45^{\circ} $
• C. $ 30^{\circ} $
• D. $ 15^{\circ} $

Answer 1

Answer: (C)

$\lambda_{x}=3500\, \mathring{A} , \lambda_{y}=7000\,\mathring{A} \sin C$
$=\frac{\mu_{2}}{\mu_{1}}=\frac{\lambda_{x}}{\lambda_{y}}=\frac{3500}{7000}$
$=\frac{1}{2} \sin C$
$=\sin 30^{\circ}$
$\therefore C=30^{\circ}$