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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
audiofeil
4,011 posts
 
Only 2 electrons.

One to hold the bulb and the other to turn the chair.

Basic electrical theory.
geoffkait's avatar
geoffkait
14,147 posts
 
The OP was trying to relate the number of electrons at the amplifier output to the current, which is why he included the math for charge per electron and ampere. If one accepts his premise that the number of electrons available at the amp's output is proportional to the current, then for the one Ampere case the number of electrons would be around 10 to the power 19. More than a trillion trillion.

Cheers
hifihvn
943 posts
 
As I said earlier, if the OP was asking about the number of electrons that might make a complete round-trip from amp terminal to speaker and back to the other amp terminal, then I certainly agree that the number would be zero or close to it

Almarg, would the close to it part be do to any resistance?
elizabeth
6,726 posts
 
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.
As mentioned electrons actually on average drift 1 cm per hour. and that is sort of the thing here. They are drifting in an A/C current about the same as if not any current. For DC current: "For an electric current of 1 ampere, 1 coulomb of electric charge (which consists of about 6.242 × 10to18 power (or 6,242,000,000,000,000,000) elementary charges (electrons) drifts every SECOND through any plane through which the conductor passes."
So if there is a slight DC current Even a tiny DC (Direct current) current of 0.00001 ampere ,there are a LOT of electrons flying around from amp to speaker and back.

OK for you math wizards:
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? (this is reasonable considering all the coils, and wires in the speaker. Assume it is a one driver speaker to avoid complications. (it has to be a pretty small offset!!!...And just so you know, I could not possibly answer the question I ask.)
bifwynne
2,069 posts
 
Billions and billions.

Carl Sagan (not bifwynne)
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