1. Not finding help here? Sign up for a free 30min 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!

Mesh Analysis - (4 meshes)

  1. Feb 15, 2007 #1
    Mesh Analysis -- (4 meshes)

    1. The problem statement, all variables and given/known data


    2. Relevant equations


    3. The attempt at a solution

    Loop 1 is the top left loop.
    Loop 2 is the top right loop.
    Loop 3 is the bottom right loop.
    Loop 4 is the bottom left loop.
    (Think of the quadrants in the cartesian coordinate system... thats my loop and loop currents).

    Loop currents are going in the CW direction.

    For Loop 1:

    -14 + I_1 + (I_1 - I_2) + (I_1 - I_4) = 0

    For Loop 2:

    I_2 = 2mA

    For Loop 3 & 4:

    Since they are super meshes because of the shared current source... this is what I have:

    4mA = I_3 - I_4
    -- and --
    using the supermesh idea, and short-circuiting the shared 4mA current source...

    I4 + 2*I3 + I3 + I4 = 0... which is 3I_3 + 2I_4 = 0

    Is my setup correct?

    If so, this is what I did...

    solved for I_4 in the equation 3I_3 + 2I_4 = 0... I_4 = (-3I_3) / 2

    I plugged that I_4 into the eq. 4mA = I_3 - I_4... and I got I_3 = 2mA.

    I assumed I_0, what we're trying to find, is equal to I_3. Is this a valid assumption since the current is going around that mesh?
  2. jcsd
  3. Feb 17, 2007 #2
    Your supermesh equation is incorrect. Starting from the lower left it should be 1k*i_4 + 1k*(i_4 - i_1) + 2k*(i_3 - i_2) + 1k*i_3 = 0

    Because of that, your assumption about I_0 is also wrong. The current in that branch is flowing between meshes 2 and 3, so the current is a combination of the two: I_0 = I_3 - I_2.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Mesh Analysis - (4 meshes)
  1. Mesh analysis (Replies: 2)

  2. Mesh Analysis (Replies: 1)

  3. Mesh analysis (Replies: 25)

  4. Mesh analysis (Replies: 43)

  5. Mesh Analysis (Replies: 9)