THE PROPERTY OF INDUCTANCE

Suppose that you have a wire 1 million (10⁶) km long. What happens if you make this wire into a huge loop and connect its ends to the terminals of a battery? A current flows through the loop, and this produces a magnetic field. The field is small at first because current flows in only part of the loop. The magnetic flux increases over a period of a few seconds as the motion of charge carriers (mainly electrons) makes its way around the loop.
A certain amount of energy is stored in this magnetic field. The ability of the loop to store energy in this way is the property of inductance, symbolized in equations by an italicized uppercase letter L.