Electric field by a current carrying wire

[jaobyccdee]

Aside from magnetic field, Does a wire carrying current induce also an electric field? If yes, what rule should i use to find its direction?

 

[Dick]

Does a wire carrying a current have a net electric charge? What do you think?

 

[jaobyccdee]

Yes, so negative charges go one way, and positive charges go another direction. Isn't it?

 

[Dick]

Yes, so negative charges go one way, and positive charges go another direction. Isn't it?

The picture is usually that negative charges (the electrons) go one way and the positive charges (the atoms that have lost an electron) are fixed in a metal. But there's no reason to assume there are more of one than the other. If there is a net charge then you can't compute it from the current. No, there is no electric field that you can figure out from just knowing the current.

 

[jaobyccdee]

1. If there are the same number of positive charge and negative charge, then there's no net charge, and thus no electric field?
2. Can i say since a constant current has a magnetic field that doesn't change, so an electric field is not induced?
3. If the number of positive charge and negative charge are not the same, there is a net charge, then is there an electric field?
4. does a static current same as a constant current?

Thanks a lot!

 

[Dick]

1. If there are the same number of positive charge and negative charge, then there's no net charge, and thus no electric field?
2. Can i say since a constant current has a magnetic field that doesn't change, so an electric field is not induced?
3. If the number of positive charge and negative charge are not the same, there is a net charge, then is there an electric field?
4. does a static current same as a constant current?

Thanks a lot!

1. That's what Gauss' law would say. 2. A constant current creates a constant magnetic field - but that's not why the electric field is zero. 3. If the wire has a net charge, there will be an electric field. 4. I don't know what "static current" means - the only way I can think of the interpret it is "constant current".