What is the principle behind electromagnetic induction?

The principle behind electromagnetic induction is that a changing magnetic field induces an electromotive force (EMF) in a conductor. This phenomenon is a key concept in electromagnetism and is primarily described by Faraday's law of induction. According to this law, when the magnetic field around a conductor changes—whether through the motion of the magnet relative to the conductor or the change in the magnetic field strength itself—an electric current can be generated in the conductor.

This process is fundamental to the operation of many electrical devices, such as generators and transformers, making it essential for understanding how electrical energy is produced and utilized in various applications. In contrast to the other options, which address different interactions between electricity and magnetism but do not directly describe the process of induction, this choice accurately captures the core mechanism by which electromotive force is generated through the dynamic relationship between magnetic fields and electric circuits.