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Calculate the B field inside and outside a wire

  • #1
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Homework Statement


A long, straight wire of radius a has current density J = J0e−β(α−ρ)uz where β is a
constant and ρ < α. Determine B inside and outside the wire.


Homework Equations


J=I/((pi)a^2)
B=(μIρ)/(2(pi)(a)^2)

The Attempt at a Solution


Here is what I did B=(μρ/2)J0e^(-β(alpha-ρ))
 
Last edited:

Answers and Replies

  • #2
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Is the problem confusing?
 
  • #3
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7
Is the problem confusing?
Not at all. First find i by integrating J then find B. di = JdA
 
  • #4
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So ∫J0e^-β(α-ρ) from 0 to a but what should I integrate with respect too?
 
  • #5
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J=di/dA maybe?
 
  • #6
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well since beta is constant and alpha is greater than rho then e^(-beta(alpha-rho)) whould go to 0 if I took the limit from 0 to infinty
 
  • #7
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hmmm well I guess the problem does not consider time as it uses J0 which I assume stands for the intial value
 
  • #8
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So my limit I idea is flawed then
 
  • #9
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Anything else?
 

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