magnetic circuit question

Discussion in 'Homework Help' started by Vanush, Sep 23, 2008.

  1. Vanush

    Thread Starter Active Member

    Apr 19, 2008
    Can someone please help me analyze this magnetic circuit? I've got no idea...!

    I want to calculate the flux in each leg.. so, let's take the first leg, flux 1

    I know that flux = BA..

    I calculate magnetizing force H = NI/l = 500/0.14 = 3571.42

    but B = u0 * ur * H = 5000*(4*pi*10^-7)*3571.42 = 22.43

    but flux = BA = 22.43 * 0.004 = 0.0089 Wb

    Not even close to the answer! (4.887 mWb)
  2. scubasteve_911

    Senior Member

    Dec 27, 2007
    You should draw the electrical circuit equivalent, so that you may apply the necessary laws. In this case, it would be the current divider rule.

    I will not solve the question for you, but I will give you the right steps to do it.

    #1) Solve for total core reluctance, this involves finding the area of the core and the length, and using the permeability. You will have a resistor in series with two parallel resistors, hopefully you can find the total resistance. (sorry, thinking electrical)
    Rcore = length / u0*ur*area
    #2) Solve for total flux
    Flux = F/Rcore = N*I/Rcore
    #3) Apply the current (or flux) divider equation to solve for the various fluxes along the different paths