- When current through a solenoid changes, a magnetic field is induced within the solenoid. If two solenoids are concentric with each other, the induced field in one solenoid produces a changing current in the other.
- Connect a power supply to one solenoid and a galvanometer to the other.
- Unless steel rod is inserted in innermost cylinder (shown above), induced magnetic field is too week to produce a noticeable effect. Steel rod greatly enhances effect.
Solenoids: L01, section B-2
Galvanometer: L35, section F-3
Power supply: L35, section F-1