Dr. Walter Lewin from MIT
Induction.mov (108MB)

Nature resists change. . .

We need to distinguish between emfs and currents
set up by batteries and those that are induced by
changing magnetic fields.

Be vigilant of Lenz's Law

Looking back. . .what do we recall?

Gauss's Law gave us the E-Field of an infinite plane (capacitor).

And

Ampere's Law gave us the B-Field around a current-carrying wire.

The increasing magnetic flux due to the changing current creates an opposing emf in the circuit.

The inductor resists the change in the current in the circuit.

If the current changes quickly the inductor reponds harshly.

If the current changes slowly
the inductor barely notices.

Once the current stops changing the inductor seems to disappear.