[kazinator]

We can make an analogy to trains. Suppose instead of a circuit, we have a long train on a circular track, completely occupying that track. To "turn on" the circuit, we begin to move one of the cars. Now there is slack in their coupling, so a ripple effect occurs: the cars do not all move a the same time, but a wave of motion begins, and this propagates in both directions around the circular track, away from the initially moved car. Eventually, both these ripples reach the opposite side of the circular track where the motion starts to occur and can be used to do some work. Then we can get into a more or less steady state: the cars are moving around the track.

This steady state of motion is like "drift current", whereas the initial ripple of couplings clattering together an initiating the motion is like the electric field propagating through the circuit.

Of course, EE's know about drift current, transmission line behavior and other topics.

[tsimionescu]

Your explanation would lead to the 0.5s answer - that's how long it takes for the first signal to ripple through the wires.

To get the 1m/c s answer, for your example you would have to add a seismograph to the opposite end of the train track - while the cart at that far end will only start moving once the ripple goes around the whole track, the seismograph will pick up the movement almost instantly, since the movement of the initial cart will send waves through the earth directly, not following the tracks.