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Find the magnetic permeability of the iron bar.

  1. Mar 23, 2016 #1
    1. The problem statement, all variables and given/known data
    In a solenoid with 12 enamels for cm passes the current 2 A. Find the magnetic permeability of the iron bar inside it.(B0=1.508 T)

    2. Relevant equations
    B=μ0*I*N/l(length)

    3. The attempt at a solution
    We have N/l(length)=1200 enamels/meter
    B=4*10^-7*3.14*25*1200=0.003T
    Now μr(relative permeability)(if this is what the problem is asking is B/B0=1/500, but in my book it is 500. Where is the error?
     
  2. jcsd
  3. Mar 23, 2016 #2

    marcusl

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    You have swapped B0 and B.
     
  4. Mar 23, 2016 #3
    I found that B=0.003, in the book B0=1.508. μr=B/B0=0.003/1.508=1/500. Where did I make the mistake?
     
  5. Mar 23, 2016 #4

    marcusl

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    B0 is usually used to indicate field in a vacuum and B is the field in the material. B0=.003 and B=1.5, so mu=500.
     
  6. Mar 24, 2016 #5
    But in this case B0=1.5 T(I found out) and B=1.5 T (given by the book)
     
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