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: Magnetic flux problem

  1. Dec 7, 2004 #1
    Find the magnetic flux crossing the portion of the plane
    theta = x/4 defined by 0.01 m < r <0.05 m and 0 m < z < 2 m. A current of 2.50 A is flowing along z-axis along a very long wire.

    in drawing the picture i know that there is a long thin wire with a current of 2.5 amps flowing positively on the z-axis and the plane is lying rotated at an angle of pi/4 with the magnetic field flowing in a counter clockwise direction.

    How do I go about finding the magnetic flux.
    Please help.
  2. jcsd
  3. Dec 8, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper

    Should that be theta=pi/4?

    [tex]\Phi_B=\int_P \vec B \cdot d\vec a[/tex]

    Since the plane lies parallel with the z-axis, its normal points in the same direction as the magnetic field everywhere in the plane, so you can drop the dot in the integrand

    [tex]\Phi_B=\int_P B da[/tex]

    Recall that the magnitude of the magnetic field of a long wire is:

    [tex]B(r)=\frac{\mu_0 I}{2\pi r}[/tex]
    where r is the distance from the wire.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook