What happens to the frequency of light as its wavelength increases?

• A. The frequency increases.
• B. The frequency remains the same.
• C. The frequency decreases.
• D. The frequency becomes zero.

Answer: (C)

The relationship between the frequency and wavelength of light is an inverse one, described by the equation ( c = \lambda f ), where ( c ) is the speed of light, ( \lambda ) is the wavelength, and ( f ) is the frequency. As the wavelength ( \lambda ) increases, in order for the speed of light ( c ) to remain constant, the frequency ( f ) must decrease.

This means that longer wavelengths correspond to lower frequencies. Frequency is essentially the number of waves that pass a given point in one second, so if the waves are spreading out (as indicated by an increase in wavelength), fewer waves will pass that point in the same amount of time, resulting in a lower frequency. Hence, the assertion that the frequency decreases as wavelength increases is accurate and aligns perfectly with the fundamental properties of light.