Wave Optics – Solutions
1) Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of (a) reflected and (b) refracted light? The refractive index of water is 1.33.
(a) For reflected wave (light): the wavelength will remain unchanged.
According to the question:
Wavelength of incident wave, λ = 589 nm = 589 x 10-9 m
Speed of light in air, c = 3 x 108 m s-1
Since c = vλ, where v is the frequency of light
v = c/λ = /589 x 10-9
v = 3/589 x 1017 = 5.09 x 1014 Hz