Determination of direction in AC Power Flow

But the individual electron doesn't go "pinballing" at 1E6M/S. Again, how would you tag the individual electron to see?

Typical == drift velocity.

It ma be 1E6M/S over 1E-10M. ;-)

What is there to think about? Are you confused because there are a fixed number of electron charges that make up a coulomb's worth of charge?

Do you go around saying I would like a quart of hot water's worth of sugar because a quart of hot water weighs about that of a bag of sugar?

To look at it another way - if find out that a dark matter electron has half a coulomb of charge, which electron are you going to use?

And still another way - where in the definition of coulomb is the electron?

Absolutley.

I don't think you understand charge.

What is the charge of an electron?

I'm not confused at all.

Don't be stupid.

In what universe do you live in?

You flunk. Show me an electron with a different charge.

If that's what you think you don't think.

1 coulomb/avagadro's number

You are

Apaprently the real one

One coulomb is the charge in one amp of current flwoing for one second.

No electrons

Show me a coulomb that requires an electron to have its charge.

Does too.

Tag an individual electron. I don't know why you think science is so simple as to not be able to derive a meaningful value for a typical speed for an electron in an electron gas, or why you think each individual electron would have to be 'tagged' in order to do so. I have a dinner plate here with ten pieces of potato on it. I am lifting the dinner plate at 0.3 m/s. I conclude that a typical speed for a piece of potato on the plate is 0.3 m/s. I have not tagged any individual piece. This falsifies your tag hypothesis.

No, the drift velocity is a net change in position over a longer time interval (and might commonly be around 10^-4 m/s) and has nothing to do with typical speed (which is on the order of 10^6 m/s). 10^-4 m/s =/= 10^6 m/s. Typical instantaneous =/= average. Maybe you do not know what I mean by 'pinballing'. Which is fine.

Yes. Exactly. The mean free path between collisions may be on the order of

10^-10 m. BUT, after a collision the electron might bounce away at any crazy angle. It does NOT progress down the conductor in a series of straight, aligned, 10^-10 m steps. A typical speed between these collisions is 10^6 m/s. Based on these last four statements we see that an electron pinballs through a lattice with a typical speed of 10^6 m/s. j

According to accepted quantum theory, electrons are fundamentally indistinguishable from one another. This leads to the Fermi-Dirac statistical behavior of electron assemblages such as found in metals. This indistinguishabilty has profound consequences on semiconductor behavior, specific heat of metals, and many other aspects.

Bill

-- Fermez le Bush

Thank you. I think we realize this, I think that is why the other poster asked how I would intend to tag an electron, implying that that the inherent indistinguishability of electrons would prevent one/me from obtaining a value for the speed of an individual electron. The quantum mechanical description you discuss is what leads to the determination of the correct value for the average speeds of electrons in a conductor, on the order of

10^6 m/s. j

On Thu, 16 Nov 2006 21:36:00 -0500, krw Gave us:

To answer the post title:

It flows BOTH ways, and it dissipates as heat in loads.

On Fri, 17 Nov 2006 11:04:34 -0600, "hob" Gave us:

Within the frame of the definition of the word Ampere.

One Ampere Second is a count of electrons passing a point of reference per unit time because one ampere is a rate of electron flow.

High repeat rate pulse lasers need cap banks charged by high output power supplies to keep up with the pulse rate.

That's-a-lotta coulombs.

Every element in a series circuit loop has that same flow as well. What comes out must go back in.

Yes, the coulomb is directly related to electron flow.

Tag one and measure its speed then.

The "average"? The average would be the drift velocity.

On Fri, 17 Nov 2006 15:13:53 -0500, krw Gave us:

As well as:

So you agree that the charge of an electron is a constant. It's not a huge leap from there to understand that a coulomb represents a fixed number of electrons. QED.

Are we talking AC now? What relevance does this have to the discussion at hand?

This is like a broken record. I am comfortable that there are other ways to determine useful numbers for the average speeds of electrons in conductors. Science has done so. The speeds are on the order of 10^6 m/s.

The average speed is not the drift velocity. The average speed will be on the order of 10^6 m/s. Speed is a scalar.

Later

j

The magnitude of a coulomb was reasonably well know before people knew that electrons existed. Not even Avogadro's number was known. Electrical units were defined in mechanical terms. A statcoulomb was the magnitude of equal point charges that when place 1cm apart produced a force of 1dyne. Potential was derived from that. The trick, developed by Millikan was to determine how much charge was on an electron--not the other way around.

Bill

-- Fermez le Bush

Why do you insist on the tail wagging the dog?

Bill

-- Fermez le Bush

Define "average speed" then. Seems to me this would be the average of the speed of the valence electrons along the wire (a.k.a. "drift velocity").

Speaking of broken record...

So the electrons are moving at right angle to the conductor?

Sometimes it's useful to turn the problem around and look at it from the other end? Definitions are made by people. The universe isn't.

The electrons are going all over the place, like molecules in a gas, with a slight slight slight tendency to move along the wire under the influence of the E field. Roughly speaking this movement along the wire gives the drift velocity, while all the whipping around - pinballing from atom to atom of the lattice - happens at a huge speed and gives rise to the average speed.

Yes. I am horrified that I have had to repeat it so many times especially considering that (1) it comes from physics texts and (2) you have already agreed with it yourself [[ "j: ...speeds between collisions are about

10^6 m/s. This speed may be the thermal speed of the electron to a great extent. krw: It ma be 1E6M/S over 1E-10M. ;-) j: Yes. Exactly. ..." ]] .

Yes. They are going in every direction wrt the conductor. They are going absolutely ape shit pinballing from atom to atom of the lattice. With no particular tendency for net movement in any direction until an E field is applied. When someone applies an E field their behavior is still close to this random crazy pinballing, though a slight tendency toward net movement along the conductor arises. The drift velocity.

j