Average Electron Drift Distance with AC Current

AI Thread Summary
The discussion focuses on calculating the average electron drift velocity and drift distance in a metal wire carrying a 60 Hz alternating current. The drift velocity expression is derived using the relationship between current density and electric field, incorporating the number of free electrons. The challenge lies in determining the average drift distance of electrons during a half-cycle of the alternating current, with participants struggling to find values for conductivity and electric field. The calculations involve determining the average current density and the charge movement per second. Overall, the thread emphasizes the complexities of applying theoretical equations to practical scenarios in AC current.
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Homework Statement


A metal wire with 1023 free electrons per cubic centimeter is carrying 60 Hz alternating current with a maximum current density of 100 amps/cm2.
a) Write an expression for the average electron drift velocity as a function of time (vd as a function of time).
b) What is the average drift distance of free electrons in one direction in a half-cycle of current?

Homework Equations


J = σE = σEsin(ωt)
ω = 2πν
J = -eNevd

The Attempt at a Solution


Part a:

J = -eNevd
-eNevd = σEsin(ωt)
vd = (-σEsin(ωt)) / (eNe)

Part b:

Need help here, I attempted to plug in ω = 2πν into the equation J = σEsin(ωt), but don't seem to be getting anywhere, because I don't have σ or E.
 
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achap6 said:
A metal wire with 1023 free electrons per cubic centimeter is carrying 60 Hz alternating current with a maximum current density of 100 amps/cm2.

Calculate the average absolute current density ( [ A/cm2 ] ).

Calculate the amount of coulombs moved per second.

Calculate the amount of centimeter wire-electrons is moved per second.
 
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