If you increase the wavelength of a wave too much, you are essentially decreasing its frequency towards zero. Similarly, if you make the frequency of a wave infinitely large, the wavelength would become extremely small. Let's explore the consequences of these scenarios:
Zero frequency (DC or Direct Current): When the frequency of a wave approaches zero, the oscillations become slower and eventually come to a standstill. This corresponds to a direct current (DC) signal, where the value of the wave remains constant over time. In terms of electromagnetic waves, this implies that there are no oscillations in the electric and magnetic fields, and the wave essentially becomes a static field.
Infinite frequency (Goes beyond the applicable range): In classical electromagnetism, the concept of an infinite frequency is not physically meaningful. Frequency is defined as the number of oscillations per unit time, and there is a practical limit to how fast oscillations can occur. When the frequency becomes extremely large, the corresponding wavelength becomes very small. At some point, the wavelength may become comparable to the scale of the underlying particles or the structure of the medium, and the classical description of electromagnetic waves breaks down. In such cases, more advanced theories, such as quantum electrodynamics, would be required to accurately describe the behavior of electromagnetic phenomena.
It's important to note that classical electromagnetism provides a useful framework for describing electromagnetic waves within a certain range of frequencies and wavelengths. However, at extremely low or high frequencies, the behavior of electromagnetic waves can deviate significantly from classical predictions, and a more sophisticated theory, such as quantum mechanics or quantum field theory, becomes necessary to fully understand and describe the physical phenomena involved.