SQ: What makes eddy currents? To see what eddy currents are watch Lenz' Law Video

Exploration: Consider the conducting loop in the region of increasing magnetic field.

Changing Magnetic Fields Make Electric Fields

What direction is the induced current in the loop?

What specific force must drive the current in the loop?

Where did that force come from?

Now remove the loop. The thing that drove the current previously must still be there. Sketch it!

What about for other radii?

Let’s find the induced EMF ℇ around a complete circle of radius r where r < R: ℇ=−∫ E⃗ ∙ d⃗l=¿¿

But Faraday’s Law says:

ℇ=¿

Equating the 2 expressions for ℇ and solving for E:

Now find E for r > R by repeating these steps…

Graph it:

Big Idea:

Discussion: