Electrical Academy Level 1 Practice Test

An inductor mainly stores energy in a magnetic field created by current flowing through its coil, and it resists changes in that current. The magnetic field holds energy proportional to (1/2)LI^2, so when current tries to rise, the inductor generates a back-EMF that opposes the rise; when current tries to fall, it releases energy to help keep the current going. This resistance to rapid changes in current is what defines inductors.

This is different from energy storage in a capacitor, which stores energy in an electric field between plates. And inductors don’t rectify AC or convert AC to DC—that role belongs to diodes and rectifier circuits.