In electromagnetic behavior, how does wavelength relate to frequency?

• A. Increases as frequency increases
• B. Stays the same regardless of frequency
• C. Decreases as frequency increases
• D. Fluctuates unpredictably with frequency

Answer: (C)

Wavelength and frequency move in opposite directions for electromagnetic waves. In vacuum, the speed of light is constant, so the relationship c = fλ applies. This means the wavelength equals the speed of light divided by the frequency (λ = c/f). Consequently, when frequency increases, wavelength decreases—for example, doubling the frequency halves the wavelength. This makes sense because more rapid oscillations per second fit into a shorter distance per cycle. In other media, the exact speed can vary with frequency (dispersion), but the core idea remains that higher frequency corresponds to shorter wavelength when the wave speed is relatively stable.