Monochromatic light of wavelength 589 nm in incident from air on a water surface. If `mu` for water is 1.33, find the wavelength, frequency and speed of the refracted light.

Explanation

Velocity of light in air is nearly equal to the velocity of light in free space.
`therefore "Velocity of light in air" = v_(a) = 2.99 xx 10^(8) m *s^(-1)`
`therefore "Frequency", n = (v_(a))/(lambda_(a)) = (2.99 xx 10^(8))/(589 xx 10^(8)) = 5.07 xx 10^(14) Hz`
Frequency is a fundamental property and does not change with change of medium.
`therefore " " mu = ("velocity of light in air"(v_(a)))/("velocity of light in water"(v_(w))) = (nlambda_(a))/(nlambda_(w))`
`therefore " " lambda_(w) = (lambda_(a))/(mu) = (589)/(1.33) approx 443 nm`
wavelength of the refracted light `= lambda_(w) = 443 nm.`
`therefore "Speed of the refracted light", v_(w) = (v_(a))/(mu) = (2.99 xx 10^(8))/(1.33)`
`approx 2.55 xx 10^(8) m *s^(-1)`