What is an inductor and how does it store energy in a circuit?

The basic principle behind how an inductor stores energy involves the interaction between the electric current passing through the inductor and the magnetic field it generates. When current flows through the coils of an inductor, a magnetic field is generated around the coils according to Ampere's law. This magnetic field stores energy in the form of potential energy, similar to how a compressed spring stores energy in a mechanical system.

When the current through the inductor changes, whether increasing or decreasing, the magnetic field around it also changes. This change in magnetic field induces a voltage across the inductor according to Faraday's law of electromagnetic induction. This induced voltage opposes the change in current, resisting any sudden changes in the current flowing through the inductor. This property is known as inductance.

In mathematical terms, the voltage across an inductor (V) is proportional to the rate of change of current (di/dt):

V = L * (di/dt)

Where:

V is the voltage across the inductor.

L is the inductance of the inductor, measured in henries (H).

di/dt represents the rate of change of current.

Because the inductor opposes changes in current, it resists sudden increases and decreases in current flow. This property is commonly used in applications like energy storage and filtering. For example, inductors can be used in combination with capacitors to create LC circuits that store and exchange energy between the electric and magnetic fields, resulting in resonant behavior.

In summary, an inductor stores energy in the form of a magnetic field generated by the current passing through it. This stored energy can be released back into the circuit when the current changes, and this behavior has important applications in various electronic systems.