What is induction?
Induction comes from the root induce because it refers to an induced voltage. By changing the magnetic flux (field times area) inside a loop of wire, a voltage is induced around the loop. This is the manner in which the power company takes the kinetic energy of moving turbines and changes it into electrical energy.
We will find that it is changing magnetic flux that induces a voltage, and that it can be brought on by either changing the field or the area. We will also introduce a concept of inductance, which will give the induced voltage as a function of the rate of change of current. This will be crucial for understanding AC circuits in the next lecture.