Elective induction: When? Ever?

William A Grobman1

  • 1Department of Obstetrics and Gynecology, Northwestern University Medical School, Chicago, Illinois, USA. w-grobman@northwestern.edu

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Induction

An emf is induced when the magnetic field in a coil is changed by pushing a bar magnet into or out of the coil. emfs of opposite signs are produced by motion in opposite directions, and the directions of emfs are also reversed by reversing poles. The same results are produced if the coil is moved rather than the magnet—it is the relative motion that is important. The faster the motion, the greater the emf. Additionally, there is no emf when the magnet is stationary relative to the coil.
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An inductor, also known as a choke, is a circuit component created to have a specific inductance. Inductors are among the crucial circuit components used in modern electronics, along with resistors and capacitors. They serve as a barrier against changes in a circuit's current. An inductor tends to suppress current changes in an alternating-current circuit that are faster than desired. In a direct-current circuit, an inductor aids in preserving a constant current despite changes in the applied...
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