# What is Meant by Inductance

## Introduction to Inductance

The behaviour of the inductor is based on the properties of the magnetic field generated in a coil of wire. In fact, the inductor is basically a coil of wire.

The behavior of the capacitor is based on the properties of the electric field created in a

dielectric (non-conductor) placed between two conductors.

### Self-inductance

Inductance is the name given to the property of a circuit whereby there is an e.m.f. induced into the circuit by the change of flux linkages produced by a current change. The unit of inductance is the henry, H.

When the e.m.f. is induced in the same circuit as that in which the current is changing, the property is called self-inductance, L.

### Mutual inductance

When an e.m.f. is induced in a circuit by a change of flux due to current changing in an adjacent circuit, the property is called mutual inductance, M.

There is a relationship between current and voltage for an inductor, just as there is for a resistor. However, for the inductor, the voltage is related to the *change *in the current, as follows.

Where diL/dt is the rate of change of current in the first coil

The induced e.m.f., E, in a coil of N turns,