A copper hoop in a magnetic field

Understanding Electromagnetic Induction

Electromagnetic induction is a phenomenon where a changing magnetic field induces an electromotive force (emf) in a conductor, such as a copper hoop, resulting in the generation of an electric current in the loop.

Faraday's Law of Electromagnetic Induction

Faraday's law states that the induced emf in a circuit is directly proportional to the rate of change of magnetic flux through the circuit. In other words, the greater the change in magnetic flux, the larger the induced emf.

Orientation of the Copper Hoop

When a copper hoop is held in a vertical east-west plane in a uniform magnetic field with field lines running along the north-south direction, rotating the hoop about an east-west axis leads to the highest induced emf. This is because rotating it in this orientation results in the maximum change in magnetic flux through the loop.

Rotating the copper hoop about a north-south axis or moving it rapidly without rotation towards any direction would not result in significant changes in the magnetic flux, leading to lower or no induced emf, respectively.