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Using Kirchhoff's rules to calculate current

  1. Mar 5, 2012 #1
    1. Calculate the three currents indicated in the circuit diagram below.

    I have attached the diagram.

    How would I use Kirchhoff's laws to find the currents I am getting thrown off by the third loop.
     

    Attached Files:

  2. jcsd
  3. Mar 5, 2012 #2

    gneill

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    Staff: Mentor



    How are you "getting thrown off by the third loop"? You'll have to show your attempt at a solution so we can see how to help.
     
  4. Mar 5, 2012 #3
    Solution attempt:

    I1 loop 9.00V-9.00(I1)=0 so I1=1A
    I2 loop 12.00v-6.00(I2)=0 so I2=2A
    For I3 loop 12.00V-10(I3)-8(I1)-1(I2)=0 by plugging in I1 and I2 I get I3 to be 5A.
     
  5. Mar 5, 2012 #4

    gneill

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    Staff: Mentor

    Ah. Don't forget to apply KCL at the nodes where currents join/split. For the "I1 loop", for example, I3 joins the party at the rightmost node, so the current through the 8.00 Ohm resistor is actually I1 + I3. Label the net currents on wires around the nodes.
     
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