Question

Light of wavelength 5000 $\dot{A}$ falls on a plane reflecting surface. What are the wavelength and frequency of the reflected light? For what angle of incidence is the reflected ray normal to the incident ray?

Answer 1

$\lambda =5000\times {10}^{-10}m$

$\nu =\frac{c}{\lambda }=6\times {10}^{14}Hz$

For the reflected light, $\lambda ,\nu$ remains same.

$i$ is the incident angle. $r$ is the reflected angle.

$i+r={90}^o$

By, law of reflection, $i=r$

$\Rightarrow i=r={45}^o$