1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Magnetomotive force and the H-field

  1. Aug 28, 2012 #1
    1. The problem statement, all variables and given/known data

    The magnetomotive force is given as an integral of the H-field. I want to know how this can be a force.

    2. Relevant equations

    [tex]\int H \cdot d \ell = F[/tex]

    3. The attempt at a solution

    So a bit confused. Wiki says that this equation

    [tex]\int H \cdot d \ell = F[/tex]

    is a force, the magneto-motive-force. But this is the H-field multiplied by a length [tex]\ell[/tex]. From what I knew about the H-field, if you multiply the H-field with a length, you should get a current, not a force as

    [tex]\int H \cdot d\ell = I[/tex]

    I know this because

    [tex]H = \frac{I}{2\pi r}[/tex]

    you can see why by rearranging it

    [tex]H \cdot r = \frac{I}{2\pi}[/tex]

    so what gives?

    Thanks in advance.
  2. jcsd
  3. Aug 28, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    It's analogous to electromotive force. Neither electromotive force or magnetomotive force is a force in the traditional sense. That is, it's not measured in newtons in the SI unit system.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook