Current Question: How Many Electrons in Copper Wire/sec?

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A copper wire with a cross-sectional area of 2 mm² carries a current of 10 A, prompting a discussion on calculating the number of electrons passing through the wire per second. The relationship between current, charge, and time is clarified, with the formula stating that current (in Amperes) equals charge divided by time. To find the total charge, the current is multiplied by time, and then this charge is divided by the charge of a single electron, which is approximately 1.6 x 10^-19 coulombs. The area of the wire is deemed irrelevant for this specific calculation. The discussion effectively leads to the conclusion that understanding the definition of current is key to solving the problem.
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A copper wire of cross sectional area 2 mm^2 carries a current of 10 A. How many electrons pass through a given cross sectional of the wire in one second?
 
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What's the definition of current?
 
Err V= IR?

But I don't know how to relate with Area...
 
cremedelacreme said:
Err V= IR?
Nope. That's Ohm's law. Hint: What does the unit Ampere mean? 1 A = ??
But I don't know how to relate with Area...
Perhaps the area is irrelevant. :wink:
 
Err

Ampere = Charge / Time
So

Charge = Ampere / Time

ooh
we find the charge
and since
one electron has a charge of 1.6 x 10^-19
thus, we divide the charge by the charge of one electron...

is it correct?
 
cremedelacreme said:
Ampere = Charge / Time
Right!
So

Charge = Ampere / Time
Careful: If Current = charge/time then charge = current * time.
ooh
we find the charge
and since
one electron has a charge of 1.6 x 10^-19
thus, we divide the charge by the charge of one electron...
Good!
 
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