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ricky25j
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Homework Statement
For what electric field strength would the current in a 2.0-mm-diameter nichrome wire be the same as the current in a 1.0-mm-diameter gold wire in which the electric field strength is 0.0095 N/C?
dn = .002m
dg = .001m
Eg = .0095 N/C
ρn = 100 * 10-8 Ωm
ρg = 2.44 * 10-8 Ωm
Homework Equations
V = IR
R = ρL/A
V = E * Δs
The Attempt at a Solution
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First, I found a general equation for current in a wire:
V = IR
I = V/R
I = (E*Δs)/(ρL/A)
I = EA/ρ
Then, I used this to find the current in the gold wire (and by extension, the nichrome wire).
In = Ig = Eg * Ag / ρg
I then used the I = EA/ρ equation to find an expression for the electric field in the nichrome wire, and plugged in the above value for the current.
En = In * ρn / An
En = (Eg * Ag * ρn) / (ρg * An)
I then plugged in the values and solved.
En = [(.0095 N/C)(π*(.001m)2/4)(100*10-8Ωm) / [(2.44*10-8Ωm)(π*(.002m)2/4)]
= .0973 N/C
Webassign is not accepting this answer. Does anyone know where I went wrong?
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