Question

Define magnetic induction

Answer 1

The term "magnetic induction" can refer to one of two things.

For one, sometimes the magnetic field, BB, is called the "magnetic induction." I personally never call it that. The magnetic field is also sometimes referred to as the magnetic flux density; I sometimes call it that.

More often "magnetic induction" refers to the fact that a time-varying magnetic field generates loop-like electric fields, which in the presence of a conductor will cause the flow of currents.

In the fully three-dimensional set of Maxwell's equations, magnetic induction is encapsulated in Faraday's law:

∇×E=−∂B/∂t

Given a conducting wire that forms a closed loop, this reduces to Faraday's law of induction, which states that a time-varying magnetic flux through the loop induces a voltage (electromotive force) in the wire:

ϵ=−dΦ/dt