We talk about electrical current — just like current in a stream ... and resistance to changes in pipe volume. Of course, you probably figured out that analogy doesn’t — ahem — hold ...

electrical current behaves like water flowing through a closed ring of piping. The movement of the water through the pipe is like the movement of electrons through a circuit. The diagram shows a ...

You do not want a magnet inside your body, so never suck on a pipe that has a magnet ... in the demonstration is due to an eddy current. That's an electrical current that forms in the copper ...