Results 1 to 4 of 4

Math Help - conductors

  1. #1
    Member
    Joined
    Dec 2007
    Posts
    76

    conductors

    How far from a long conductor passing a current of 12.5A is the magnetic field of strength 3.1x10^-5 T?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,212
    Thanks
    419
    Awards
    1
    Quote Originally Posted by johett View Post
    How far from a long conductor passing a current of 12.5A is the magnetic field of strength 3.1x10^-5 T?
    Presumably the conductor is a wire of some kind. (Rather than, say, a rectangular solid, which would distort the magnetic field lines.) What does Ampere's Law have to say about the magnetic field due to a long wire?
    B = \frac{\mu _ 0I}{2 \pi r}
    where r is the distance from the center of the wire.

    -Dan
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Dec 2007
    Posts
    76
    What would the  \mu be in this case? Is it a constant?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Forum Admin topsquark's Avatar
    Joined
    Jan 2006
    From
    Wellsville, NY
    Posts
    10,212
    Thanks
    419
    Awards
    1
    Quote Originally Posted by johett View Post
    What would the  \mu be in this case? Is it a constant?
    Ummm...
    \mu _0 = 4\pi \times 10^{-7} \frac{N}{A^2}

    The "permeability of free space?" If you are doing this problem you have to have run into this constant before!

    Edit: Perhaps you know of your magnetic field as
    B = \frac{c^2I}{2\pi \epsilon _0 r}

    In that case we have the identity c^2 = \epsilon _0 \mu _0 where c is the speed of light.

    -Dan
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. find total charge of three concentric spherical conductors
    Posted in the Advanced Applied Math Forum
    Replies: 1
    Last Post: January 28th 2010, 08:59 AM
  2. Resistance produced by three conductors
    Posted in the Calculus Forum
    Replies: 6
    Last Post: July 28th 2009, 01:00 AM

Search Tags


/mathhelpforum @mathhelpforum