If all the kinetic engery is used when electrons moves through a reisitor, what gives it the power to return?

Question

I am having problems understanding what happens to electrons once they have exited a reisitor. For example, lets say you a very simple circuit - a 12V battery with a single bulb attached using a couple of wires. Now let's imagine the 'go' and 'return' wires have 0 resistance. If you was to now place a multimeta on the terminals each side of the bulb, it would read 12V - incidating that ALL the volage has dropped across the bulb. This is what I don't understand - if voltage is the moving 'force' and all the 'force' is used-up pushing the electrons through the bulb, then what is giving the electrons the 'force' or 'power' to return down the wire and back into the battery if all their kinetic engery has been used getting through the bulb?

Answer 1

The only way your assumption can be satisfied is for the wires to be superconducting. Then, the voltage across each wire would be zero. There's not a simple explanation of superconductivity. Until recently, there wasn't any explanation at all. See the reference.

If the wires are not superconducting, the voltage across them is not zero, and the voltmeter would read less than 12 volts. There would be an electric field along the length of each wire, and the net electron flow would be governed by that electric field.

Answer 2

Hi>
The simple answer is that there is energy loss through any medium or device. In power engineering, I consider a conductor to have a particular voltage drop, depending on size of conductor, type, and of course distance. (amount of stuff in the way).
The energy is mainly dissapated in thermal energy, and audio, when you listen to a loaded up power-line.
Same in electonic circuits, loads of electrons finding their way from A to B.
Use a REALLY accurate meter on the circuit, and there is displayed the energy loss, easily calculable.
All the potential diffence, or voltage does not reach tje other end.
Good fun working it all out, though.

Bob.

Answer 3

The wire has a trivial resistance to it so there will be a tiny voltage drop across the leads too. However, as you say the required power output to overcome this trivial friction is nil.

Answer 4

In this case it is the momentum of the electrons that takes them through the zero resistance wire back to the terminal.

Answer 5

Energy

Answer 6

no, stop annoying us with your problems

Answer 7

do you mean resistor