Question

The wavelength of light in two liquids x and y are $ 3500\overset{\text{o}}{\mathop{\text{A}}}\, $ and $ 7000\overset{\text{o}}{\mathop{\text{A}}}\, $ , then the critical angle of x relative to y will be

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

Answer 1

Answer: (C)

$ {{\lambda }_{x}}=3500\,\,\overset{\text{o}}{\mathop{\text{A}}}\,,\,\,{{\lambda }_{y}}=7000\,\,\overset{\text{o}}{\mathop{\text{A}}}\, $ $ \sin C=\frac{{{\mu }_{2}}}{{{\mu }_{1}}}=\frac{{{\lambda }_{x}}}{{{\lambda }_{y}}} $ $ =\frac{3500}{7000}=\frac{1}{2} $ . $ \sin C=\sin {{30}^{o}} $ $ \therefore $ $ C={{30}^{o}} $