How many electrons?


There is a lot of current between your amp and your speakers. Imagine that you are doing some normal listening to your favorite loud music, and consider the number of electrons that move between the amp output poles and the speaker cables every second, in either direction.

Among the following estimates for the number of such electrons, which one is the most accurate?

a) None
b) Between eighty seven and a thousand
c) Thousands
d) Millions
e) Billions
f) Trillions or more

It's OK to just guess, but if you want to use numbers, the unit of current is an ampere, which is a coulomb per second, and an electron has a charge of about
1.602176487(40)×10−19 coulombs.
trebejo
06-10-11: Hifihvn
Almarg, would the close to it part be do to any resistance?
Elizabeth's subsequent post provided a good answer as to the reason for the "close to it" part:
06-11-11: Elizabeth
The number which would make the round trip might be some whole number, only because of the incredible number involved. So some, just because of random behavior, even though it is VERY unlikely, might just by chance manage the amazing feat.
The number of electrons that are involved, btw, is far larger than the "well over a million trillion" that I mentioned in my first post near the start of this thread. That number referred just to the number of electrons oscillating back and forth across a single cross section of the conductors, over a very short distance. A similar number of different electrons would be oscillating back and forth across every other cross section spaced some small distance apart over the length of each conductor.
06-11-11: Elizabeth
How small a DC offset in volts, would be needed to allow an average of one electron per second to start the round trip from amp output to speaker, through speaker wires etc and back if the total distance traveled is 100ft. and how long would it take the electron, on average?
I don't think that a meaningful answer can be calculated, because drift velocity is proportional to current (see this Wikipedia writeup), and for such a small current drift velocity would become essentially zero.

It should be noted, btw, that the 1 cm/hr figure that has been stated a number of times above will vary widely depending on current. As shown in the example near the bottom of the Wikipedia page, for 3 amps flowing through a 1 mm diameter (about 18 gauge) copper conductor, drift velocity is about 1 meter/hour. 3 amps rms corresponds to 72 watts into an 8 ohm load. A drift velocity of 1 cm/hr would correspond to a current of 30 milliamps in that size wire, which is 7.2 milliwatts into an 8 ohm load.

All in all, I'm starting to think that Bill (Audiofeil) had the best answer :-)

Regards,
-- Al
I can't believe how difficult this has been.

Stereo speakers run on AC. AC is Alternating Current. Since we use Alternating Current there is no net transfer of electrons to the speaker. (Your speakers are NOT like a car battery that you would charge with DC)

Simply put, if your speakers were being charged and electrons were constantly building up inside them then eventually they would become highly charged like a battery.
06-11-11: Shadorne
Stereo speakers run on AC. AC is Alternating Current. Since we use Alternating Current there is no net transfer of electrons to the speaker. (Your speakers are NOT like a car battery that you would charge with DC)

Simply put, if your speakers were being charged and electrons were constantly building up inside them then eventually they would become highly charged like a battery.
Hi Shadorne,

Agreed. I don't think anyone has said anything inconsistent with this.

Best regards,
-- Al
But the OP was not referring to the "transfer of electrons to the apeaker." Pretty sure that's what they call a Strawman Argument. LOL
Hey Al, so . . . you agree with Bill (Audiofiel). What do you have against Carl Sagan (not bifwynne)???