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Homework Help: Uniformly Magnetized Cylinder (B/H Field)

  1. Nov 23, 2011 #1
    1. The problem statement, all variables and given/known data

    See figure attached.

    2. Relevant equations

    3. The attempt at a solution

    Can someone explain to me why he uses,

    [tex](z' -z) \quad \text{ and } \quad dz'[/tex]

    What is the meaning of the ' ?

    When I did this question, I preformed the integration with the limits from 0 to L with the z in tact using a differential dz.

    Is that wrong?

    Attached Files:

  2. jcsd
  3. Nov 24, 2011 #2
    Still looking for some help!
  4. Nov 24, 2011 #3
    He's using [itex]z[/itex] to be the coordinate of the point where we want to calculate the magnetic field, and using [itex]z'[/itex] to be the coordinate of the current loop. The distance from the current loop to the point is [itex]z - z'[/itex], but he probably skipped a step and used [itex]z' - z[/itex] instead because [itex](z-z')^2 = (z' - z)^2[/itex]. To consider the effects of all the loops from coordinate [itex]0[/itex] to [itex]L[/itex], you have to integrate w.r.t. [itex]z'[/itex] from [itex]0[/itex] to [itex]L[/itex].

    If you've integrated w.r.t. [itex]z[/itex] from [itex]0[/itex] to [itex]L[/itex], then you've found the magnetic field at coordinate [itex]0[/itex], but you haven't found the magnetic field at a general coordinate [itex]z[/itex].
  5. Nov 25, 2011 #4
    Is there any other way you can reason this problem out without using the z'?

    I'd like to see the other perspectives if there are any.
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