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: Circuit mesh analysis problem

  1. Dec 14, 2012 #1
    1. The problem statement, all variables and given/known data
    EDIT: I THINK I FIGURED IT OUT, JUST NEED SOMEONE TO CONFIRM. I think the reason why my mesh analysis is wrong is because there is a voltage drop across the current source. Am I right????

    Here is the problem along with my attempt

    Find Io using mesh analysis:

    Alright so if you look at my second last and last line, i solved for i1 again to verify that my mesh was correct. However as you can see my i1 came out to be 10mA which is not the same as the i1 value that can be found by relating i1 to the 2mA current source (which is -2mA as you can see in the first line). Does anyone know what I am doing wrong? I am using the method that my professor went over in class where if you have a resistor for example in the second last line, you take the resistor and multiply it to the current difference between i3 and i1.
    Last edited: Dec 14, 2012
  2. jcsd
  3. Dec 14, 2012 #2


    User Avatar

    Staff: Mentor

    Hello TheBEAST, there are two current sources both of which are not shared between meshes, so in fact they predetermine the mesh currents for their loops. That means you begin with two out of three of the currents solved, and no need to write equations for them. For example, there's no point in trying to solve for i1 if the 2mA source has it fixed at -2mA.

    So concentrate on the second loop.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook