The wavelength (λ), speed (c) and the frequency (ν) of a wave are related as:
ν = c/λ -----(1)
The speed of the waves is a constant in vacuum i.e. it remains at 3*10⁸ m/s. therefore, it will not change with changes in wavelength or frequency.
Let us consider:
ν1 = initial frequency and λ1 = initial wavelength
ν2 = final frequency and λ2 = final wavelength = 2(λ1)
based on equation (1) we have:
ν1/ν2 = λ2/λ1 = 2(λ1)/λ1 = 2
therefore: ν2 = 1/2(ν1)
The frequency will get reduced by one-half as the wavelength doubles.
