An inductor is a passive electronic component that stores energy in the form of a magnetic field. It is typically made by winding a wire into a coil or a solenoid around a core material, such as iron or ferrite. When current flows through the wire, a magnetic field is generated around the coil, and this magnetic field stores energy.
The key principle behind how an inductor stores energy is Faraday's law of electromagnetic induction. According to this law, a changing magnetic field induces an electromotive force (EMF) or voltage in a nearby conductor. In the case of an inductor, when the current passing through it changes, the magnetic field around the coil changes as well. This changing magnetic field induces a voltage across the coil, which opposes the change in current. This property is known as inductance.
When you try to change the current flowing through an inductor, it resists this change by generating a back EMF. This effect causes the inductor to "oppose" sudden changes in current. As a result, an inductor behaves somewhat like a "reservoir" of energy. When the current through an inductor increases, it stores energy in its magnetic field. When the current decreases, the inductor releases the stored energy back into the circuit, trying to maintain the current flow.
The amount of energy stored in an inductor is proportional to its inductance (measured in henrys) and the square of the current passing through it. The formula for the energy stored in an inductor is:
Energy = 0.5 * L * I^2
Where:
Energy is the stored energy in joules.
L is the inductance of the inductor in henrys.
I is the current passing through the inductor in amperes.
Inductors are used in various electronic applications, such as in power supplies, filters, energy storage systems, and more. They are particularly useful for smoothing out current fluctuations and storing energy in circuits.