# electric field inside a coils wire

Discussion in 'General Electronics Chat' started by wes, Sep 22, 2011.

1. ### wes Thread Starter Active Member

Aug 24, 2007
242
2
How does a electric field move through a wire. I mean when I connect a coil made up of say 100 turns on a coil 1ft in diameter, does the electric field (voltage) Move from one end to other?

or does the Field sort of move from both ends and meet in the middle.
The reason for this one is I was thinking maybe that since one is positive and the other is negative, the Negative end would push electrons to move away and toward the positive and the positive end would cause electrons to move towards it since creates a pull on them. So the two fields that cause the electron movement would sort of meet in the middle.

Since the fields move at light-speed, then that means for the first one where the field moves from point a to b, it would take at least 314.1 Nanoseconds (also PI, lol ). Whereas if the field moves from both ends toward the center then it would take half that at 157 Nanoseconds.

Actually when I think about again I think it would be the first. from point a to b because since one end is technically 0 v, it could not cause any pull whatsoever. So I still want to hear from someone, just to make sure this is correct.

Thanks for any help.

And yes I am talking about the Electric Field (voltage) Not the Electrons themselves because the Electric field moves throughout the wire at the speed of light and the electrons move quite a bit slower.

2. ### mik3 Senior Member

Feb 4, 2008
4,846
63
When a point is said to be at 0V it doesn't mean that it is really at 0V. It is used just as a point of reference. I agree that one side of a voltage source is charged negatively and the other has a positive charge. Even if it is refered as the 0V point it is negatively charged. So an electron relesed between points a and b will be pushed and pulled by the negative and positive sides respectively at the same time. If the negative and positive charges are equal the electron experiences the least force in the middle between a and b. I am not sure how the field propagates, but because they represent it that it flows from the positive side to the negative I would say that PI is the correct answer (for a defined distance and circumstances).

3. ### wes Thread Starter Active Member

Aug 24, 2007
242
2
thanks for the input and yeah after more thinking about it, I think PI is the right one too, lol.