# Chicken or Egg question

#### spkwc

Joined Jul 20, 2009
1
I'm just learning electronics and have a question analogous to did the chicken or the egg come first. When voltage is produced by a generator are electrons also produced? When I plug the cord into a generator the electrons have to come from somewhere.

#### beenthere

Joined Apr 20, 2004
15,808
No, the electrons are always present in the conductors. There are just as many electrons in a copper wire that is just sitting there as in one actively acting as a conduit for current.

The circuit is always closed, meaning the electrons have a closed path to follow, so none are lost or gained.

Joined Jul 7, 2009
1,577
A voltage (potential difference) is produced whenever electrical charges are separated (ignoring changing magnetic fields for the moment); it takes energy to separate those charges. The charge carriers in matter (electrons) are always present so, unless one wants to get into cosmological considerations, it doesn't really make sense to worry which came first. Like love and marriage, you can't have one without the other. (OK, I agree, that's a crummy analogy. )

#### loosewire

Joined Apr 25, 2008
1,571
You have a still calm lake,you drop a rock In the lake,
you see the ripple's of energy. The lake will still be there
after the ripple's sub side. Another point of view.

#### ELECTRONERD

Joined May 26, 2009
1,146
Remember that energy cannot be created or destroyed. Although this doesn't seem to apply in the quantum world.

#### Ratch

Joined Mar 20, 2007
1,068

A voltage (potential difference) is produced whenever electrical charges are separated (ignoring changing magnetic fields for the moment); it takes energy to separate those charges.
Actually, it takes energy to gather like charges together because they repel one another, and are only too happy to get as far as they can away from each other. The energy it takes to gather them together divided by the number of charges is the energy density of the charge. Another name for that is voltage. In MKS units it is joules/coulomb.

Ratch

#### hobbyist

Joined Aug 10, 2008
887
You have a still calm lake,you drop a rock In the lake,
you see the ripple's of energy. The lake will still be there
after the ripple's sub side. Another point of view.

Excellent analogy, for his question.

#### studiot

Joined Nov 9, 2007
5,003
I do wish teachers would cease introducing electrons at such an early stage when discussing electricity.

In my view it only serves to confuse; it certainly raises more questions than it answers.

We cannot see electricity. We cannot see the wind. But we happily handle a basic practical appreciation if how the wind functions without any mention of fluid mechanics or the Navier Stokes equations.

#### Externet

Joined Nov 29, 2005
1,403
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Joined Jul 7, 2009
1,577

Actually, it takes energy to gather like charges together because they repel one another, and are only too happy to get as far as they can away from each other. The energy it takes to gather them together divided by the number of charges is the energy density of the charge. Another name for that is voltage. In MKS units it is joules/coulomb.

Ratch
Hi, Ratch:

It's probably not appropriate to get into the physics of charge behavior, as the OP mentioned he is just beginning his studies. He'll get all he needs when he takes his basic physics, E&M, and Electrons in Solids courses. But it is a bit of a pedagogical problem in how to expose enough without giving too much...

#### count_volta

Joined Feb 4, 2009
434
What you need to understand is free electrons. Electrons aren't produced. God made them and put them into orbit around the atom, just like he did with the planets.

Metals have electrons in the outer orbit of the atom that can leave the atom. Since they have the ability to leave they are free electrons. When those free electrons feel a positive charge, they leave the atom and move in a current. That is electricity. That is what happens in a battery.

A generator does something different. Without getting into weird quantum mechanics and such, there is a phenomenon that exists in nature. You move a magnet past a coil of wire and the free electrons in the outer orbit of the atoms that make up the coil of wire begin to move. Different reason than the battery, but its still electricity.

Take a look at my website which still needs a lot of work and updating, but it explains everything. I need to work on the graphics. http://amazing-electricity.110mb.com/index.html

That Bill Beaty website is also priceless. Especially his explanation of transistors. http://www.eskimo.com/~billb/miscon/whatis.html

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