The term "skin effect" refers to the tendency of high-frequency alternating current to flow mainly on the surface of a conductor, rather than evenly across its cross-section. To spell this term, we use the International Phonetic Alphabet (IPA) symbols /skɪn ɪˈfɛkt/. This means that the word is pronounced with a short "i" sound (like "ih") in the first syllable, followed by a stressed "e" sound in the second syllable. The "k" sound is pronounced as usual, and the final "t" is not pronounced in the standard dialect.
Skin effect is an electromagnetic phenomenon that occurs in conductive materials, such as metals, when an alternating current (AC) passes through them. It describes the tendency of the AC current to concentrate near the surface of the conductor, rather than being evenly distributed across its entire cross-sectional area. This effect becomes more prominent as the frequency of the AC current increases.
At low frequencies, the AC current flows uniformly through the entire cross-section of the conductor. However, as the frequency rises, the current starts to concentrate near the surface, particularly at the higher frequencies. This is because the changing magnetic field created by the alternating current induces eddy currents that oppose the original current flow. These opposing currents generate their own magnetic fields that tend to nullify the current within the core of the conductor, leading to a higher concentration of current flow near the conductor's surface.
The skin effect results in increased resistance to AC currents, as the conductive material effectively behaves as though it has a reduced cross-sectional area. The effective depth over which the current is distributed is known as the skin depth and is inversely proportional to the square root of the frequency. Therefore, higher frequencies face a shallower skin depth, resulting in more pronounced skin effect.
This phenomenon has practical implications in the design and use of conductors for power transmission and high-frequency applications, as it can lead to power losses, increased resistance, and heating of the conductor. To mitigate the skin effect, conductors can be hollow or composed of multiple strands, while high-frequency applications may use special materials specifically designed to reduce skin effect.
The word "skin effect" originated from the field of electrical engineering and refers to a phenomenon that occurs when alternating current (AC) flows through a conductor. The term was coined in the early 20th century to describe the behavior of the electrical current as it tends to flow more on the outer surface, or "skin", of the conductor rather than uniformly through its entire cross-section. This effect becomes more prominent at higher frequencies.
The etymology of the word itself can be traced back to the German term "Hauteffekt", which translates to "skin effect". The word was introduced by the German engineer Arnold Sommerfeld in his 1909 paper on the transmission of electric signals. It was subsequently adopted and widely used in English-speaking scientific communities.