Light of wavelength 5000 Å 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?

Explanation

Given `lambda=5000 Å =5xx10^(-7)m`
The wavelenght and frequency of reflected light remains the same.
`therefore` Wavelength of reflected light, `lambda=5000Å`
Frequency of reflected light `upsilon=(c)/(lamda)=(3xx10^(8))/(5xx10^(-7))=6xx10^(14)Hz`
The reflected ray is normal to incident if angle of incidence i=45