Question

A beam of light propagates through a medium $1$ and falls onto another medium $2$ at an angle ${45}^{\circ }$. After that, it propagates in medium $2$ at an angle ${30}^{\circ }$. The light's wavelength in medium $1$ is $141.4\dot{A}.$ Wavelength has the light in medium 2 in Angstorms is

Answer 1

Using snells law
${\mu }_1\sin {45}^o={\mu }_2\sin {30}^o$
$\frac{{\mu }_1}{\sqrt{2}}=\frac{{\mu }_2}{2}$
$\frac{{\mu }_1}{{\mu }_2}=\frac{1}{\sqrt{2}}$
$\frac{{\lambda }_2}{{\lambda }_1}=\frac{1}{\sqrt{2}}$
${\lambda }_2=\frac{{\lambda }_1}{\sqrt{2}}=\frac{141.4}{\sqrt{2}}=100\dot{A}$