1. Electromagnetic induction: A phenomenon in which current flows through the coil when the magnetic flux inside the coil changes.

2. Induction current: the current flowing when electromagnetic induction

3. Lenz's law (direction of induced current): The direction of the induced current is induced in a direction that interferes with the change of the magnetic flux passing through the coil.

4. Faraday's law (induction current magnitude): The larger the change in the magnetic field inside the coil or the larger the change in the area of ​​the vertical section of the magnetic field passing through the coil, the greater the change in the magnetic flux, the stronger the induced current flows.