Generating Current

1. Oct 11, 2005

jsalazar

I know that current is generated by charges moving in an electric field caused by other nearby charges is this phenomenon called Ohm's Law? I'm a bit confused.

2. Oct 11, 2005

jsalazar

:bump: anyone know?

3. Oct 11, 2005

Pengwuino

Ohm's law is a series of equations dictating the relationship between voltage, resistance, current, and power in DC circuits.

4. Oct 11, 2005

jsalazar

I know what Ohm's Law is, my question is, what is the phenomenon of current generating called?

5. Oct 11, 2005

Pengwuino

6. Oct 11, 2005

jsalazar

7. Oct 11, 2005

Pengwuino

I don't believe it is... I'm sure someone else will be able to answer your question better then i can.

8. Oct 11, 2005

jsalazar

thanks for your help!...can anyone else help me?

9. Oct 11, 2005

Tide

I'm not sure exactly what you have in mind but if you have a net movement of charge then you have, by definition, electrical current. The presence of an electric field may cause the flow of current to change (either increase or decrease or remain the same in some circumstances).

Do you want to elaborate on what you mean?

10. Oct 11, 2005

jsalazar

For example, if I attach a solenoid with a small cylindrical magnet going through it and attach it to a galvanometer, the needle of the glavanometer moves to a particular side depending on the conditions. Current is generated, that explains why the needle moves to a particular side. Now my question is, what is the name of this phenomenon. So far, we've only discussed electrostatics, equipotential surfaces, ohm's law, series and parallel circuits and rc circuits in class. That's why I was assuming it this phenomenon was called Ohm's Law, but I don't think I'm right.

11. Oct 11, 2005

Integral

Staff Emeritus
As mentioned above, Faraday's law, one of Maxwells equations, relates a changing electic field, a changing magnetic field and a current density. Ohms law can be derived from Maxwell equations and I belive that Faradays is the key equation in that derivation.

12. Oct 11, 2005

Tide

js,

Ohm's Law is a relationship between the current and electric and expresses that relationship in terms of properties of the medium, namely its resistivity (or resistance). The phenomenon you have in mind is called "induction" and refers to the fact that whenever magnetic fields change they induce (or make) electric fields (aka electromotive force).

This phenomenon was first studied methodically by Michael Farady. Later, James Clerk Maxwell incorporated Faraday's Law into the full set of equations that describe classical electromagnetic fields which we refer to as Maxwell's Equations. Incidentally, the electric fields induced by changing magnetic fields exist with or without any material present.

13. Oct 11, 2005

Tide

Integral,

The "derivation" of Ohm's Law does not require Faraday's Law.

14. Jul 21, 2009

joheki

please make me clear.