RL Circuits

Abstract

A circuit consisting of a resistor, an inductor, and a power supply (or Emf source) is called a RL circuit. An inductor is especially helpful in circuits where you do not want a rapidly changing current. Inductors are usually made up of coils of wire. A ferromagnetic material may be inserted in the coil to increase inductance. If you turn on current in a circuit, then the current through the coil goes from 0 to some value and hence the magnetic field due the current goes from 0 to some value along the axis of the coil. This changing magnetic field induces a back Emf in the coil, which opposes the change in current per time. We have