I have two things to ask in this thread, both pertaining to electricity.

First:

I know there was a thread about this the other day but i cant find it so:

Volts = Strength of the pull on electrons (determined by difference between neg. and pos. poles)

Amps = Current, amount of electrons flowing

Watts = total amount of power ( volts x amps)

Ohms = Resistance, lowers voltage ( not sure of effect on amps)

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Second:

Say we have an electrical current flowing through a copper wire.

I am assuming that electrons flow by being absorbed by one atom and then re-emitted just to be absorbed by the next atom in line. (Similar to how photons aren't reflected, but are absorbed and re-emitted.)

If this is so, then does the copper wire become some some isotope of copper with all those extra electrons present?

If this is not how electricity flows, then by all means please clear it up for me.

When electrons flow in a metal, its more like a fluid flowing than anything else. All the atoms in a chunk of metal share their electrons more or less evenly.

I suppose you could also try to think about it in terms of electron density. While no single atom will have an extra electron, a whole group of atoms can have an extra electron shared among them, and therefore have a slightly higher electron dnesity.

Another thing you could do is to place a charged object next to a chunk of metal. If the electrons are repelled from the electons in the hunk of metal will be pushed away to the far side and compressed, while the electons nearer to the charged object will spread out to fill the areas left empty by the other electrons.

It would not be a different isotope of copper because an isotope is something that has the smae number of protons but different number of neutrons and these stay constant - ergo can't be an isotope.

Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields. The interaction between a moving charge and the electromagnetic field is the source of the electromagnetic force, which is one of the four fundamental forces.

Electric current is the flow (movement) of electric charge. The SI unit of electric currents is the ampere (A), which is equal to a flow of one coulomb of charge per second.

Electric power is the rate at which electrical energy is produced or consumed, and is measured in watts

Electric potential is the potential energy per unit of charge associated with a static (time-invariant) electric field, also called the electrostatic potential, typically measured in volts.

There is also a generalized electric scalar potential that is used in electrodynamics when time-varying electromagnetic fields are present.


^That's off wikipedia but it tells you quite a bit very succinctly.

to add my bit:

electrons travelling around a circuit isn't like a car. each metal atom has it's own set of electrons doing their thing. at one end of the metal an electron is introduced, and at the other end, an electron is removed. since one end has an electron too many, and the other one too few, all the electrons just kinda shift across.

it is more like turning on a tap when a hose is full of water. the water that comes out of the hose is not the water that has just come out of the tap.

as for the cation/anion idea, it doesn't really work like that. metals in a solid have a "sea" of electrons (to borrow high school imagery). formal charges do not apply.

I think the word you were looking for was ion, not isotope. Assuming that is the case, I have to admit that I simply do not know. Ions generally change size when they gain or lose an electron, but do the rules change when a current is involved.

Perhaps my brother, the electrician, will know. I'll ask him.

(edit: fixed typo)

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Thanks for the replies so far

Can anyone though fill me in on the effect a resistor has on current?

A resistor resists current, as it's name implies. This causes the voltage to drop.

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But does it cause the current to drop as well?

Well, time to break out my copy of Teach Yourself Electricity and Electronics, second edition. Just to be sure.

Short answer: there is less power available after having gone through a resistor. That's the stated purpose.

Long answer: It will be a few hours, I've got to scan a graph.

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You don't have to think I'm right, as long as you think.

Yes, resistance has a lot to do with determining current. Read up on Ohms Law. A difference in potential and medium (which has some resistance) will determine amperage. Voltage is proportional to current, while resistance is inversely proportional to current; the higher the resistance, the less current. And the greater the difference of potential, the more current.