What happens to the frequency of a light wave if its wavelength increases?

When the wavelength of a light wave increases, the frequency decreases. This relationship is governed by the equation that relates speed, frequency, and wavelength: ( v = f \lambda ), where ( v ) is the speed of light, ( f ) is the frequency, and ( \lambda ) is the wavelength. Since the speed of light in a vacuum is constant, if the wavelength increases, the frequency must decrease to maintain the equation’s balance. Thus, as wavelengths become longer, the number of wave cycles passing a given point per unit time (frequency) diminishes, leading to a lower frequency overall.