What does the term "skin effect" refer to?

The term "skin effect" refers to the phenomenon where alternating current (AC) tends to flow near the surface of conductors rather than throughout the entire cross-section. This effect becomes more pronounced at higher frequencies, where the current density is significantly higher at the surface than in the core of the conductor. The reason this occurs is related to the electromagnetic fields produced by AC; as the frequency increases, it encourages the current to be pushed toward the outer edges, thereby increasing the resistance experienced by the inner regions of the conductor.

This has practical implications in electrical engineering, particularly when dealing with AC transmission and high-frequency signals; understanding skin effect helps in designing efficient conductors and cables, ensuring that they can handle the required current without excessive loss. For instance, it may influence the choice of conductor size and material in various applications, including radio frequencies and microwave transmission.