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So it just isn't popping for me how electricity actually works.

AC at 60 Hz can swap directions 60 times a second and drift at roughly 1 m/s while they kind of ping pong forward with constant push from a power source and an attraction to the positive side/protons. But if AC switches flow direction 60 times a second and the electrons only move 1 m/s how do the electrons not lose power after doing work on a load and are able to just go back and forth through a conductor and keep doing work?

And the electrons wouldn't even have enough time to move forward or backwards in a circuit they would be pretty much stuck in place just kind of vibrating back and forth never actually moving through a circuit.

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    $\begingroup$ most of this has already been answered here. $\endgroup$ – niels nielsen Jan 16 at 0:00
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    $\begingroup$ If I take hold of one end of a long rope and wave it up and down, I can send a wave along the rope, which carries energy from me to the other end of the rope, even though none of the molecules in the rope move lengthwise along the rope. $\endgroup$ – The Photon Jan 16 at 0:07
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    $\begingroup$ Electrons are nowhere near the speed of light, even in free space; electrons have mass. Also, electrons don't do any work, forces do work. $\endgroup$ – FGSUZ Jan 16 at 0:23
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    $\begingroup$ I'm voting to close this because it is all over the place, making it impossible to coherently respond to each point. $\endgroup$ – Bob D Jan 16 at 0:36
  • $\begingroup$ I trimmed it down a bit although I didn’t think it was that unclear $\endgroup$ – Dale Jan 16 at 1:45
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if ac switches flow direction 60 times a second and the electrons only move 1m/s how do the electrons not lose power after doing work on a load and are able to just go back and forth through a conductor and keep doing work?

This is a good question. In an AC circuit it is common for an electron to drift back and forth less than a cm. So how does the energy get to the load, say a light bulb?

The unspoken assumption of this question is that the energy is loaded onto the electrons who then travel and unload the energy at their destination, like a sort of delivery truck. If that were an accurate picture then indeed it would be impossible for an AC circuit to deliver any power, and even in a DC circuit there would be a long and very noticeable delay between flipping a switch and the light turning on. Therefore, since this is not what is observed the inevitable conclusion is that this picture must be incorrect.

So how is energy transferred? It is actually transferred through the fields. Poynting’s theorem describes the transfer of energy in electromagnetism. Energy transfers in a direction perpendicular to both the E field and the B field. Around a DC current carrying resistive wire there is a circumferential B field and a mostly radial E field, resulting in an energy flow mostly parallel to and outside the wire. Since the energy is carried by the fields and since the fields propagate at nearly light speed the energy transfers quickly, which is in agreement with our observations.

So where does this mistaken notion come from? Basically, in circuit theory electrical power is given by $P=IV$. Taken at face value it seems that the power is carried in the current. Since the current is made of electrons it seems plausible that the power is carried on the electrons. However, that is wrong for an important reason. The power equation gives the amount of power, but says nothing about where it is transferred. Indeed, circuit theory cannot say anything about the location of the energy transfer as all position information has been abstracted out of circuit theory. To get information about the location requires a theory that uses position: Maxwell’s equations.

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  • $\begingroup$ Thanks Dale that helps a bit. I'll have to look into Maxwell's equations and poynting's theorem. I've been reading "Practical electronics for inventors" and after ready for a while I got confused on how the electrons where moving when all the physics come into the picture. $\endgroup$ – Caleb Hathaway Jan 16 at 3:13
  • $\begingroup$ @Caleb Hathaway you are welcome. By the way, outside of chemistry and quantum mechanics the electron is a pretty useless concept. I find that at an introductory level it leads to a lot of confusion, like this. If you find yourself confused and the word “electron” is in the explanation of your confusion, most likely that will be the source of the problem, as it was here. $\endgroup$ – Dale Jan 16 at 4:26

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