Light of wavelength `5000Å` falls on a plane reflecting surface. What are the wavelength and frequency of reflected light ? For what angle of incidence is the reflected ray normal to the incident ray ?

Options

A. `0^(@)`
B. `30^(@)`
C. `90^(@)`
D. `45^(@)`

Answer

D

Explanation

Reflected ray is normal to the incident ray,
`:.i+r=90^(@)`
As `r=i:.2i=90^(@)impliesi=(90^(@))/(2)=45^(@)`