Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Junction rule

  1. Feb 10, 2009 #1
    1. The problem statement, all variables and given/known data

    find the current in I3 and I2 and I1

    2. Relevant equations
    junction Rule

    3. The attempt at a solution
    Loop 1 : -I1(4.1) + 29V - I1 (3.3) -I3(2.9)
    -I1(7.4) -I3(2.9) = -29V

    Loop 2 : I3 (2.9) - I2 (5.5) +16 V - I2(2)
    -I2(7.5) + I3(2.9) = -16 V

    Loop 3 : -I1(4.1) + 29V - I1(3-3)-I2(5.5) +16V-I2(2)

    Please help ASAP thanks!

    Attached Files:

  2. jcsd
  3. Feb 11, 2009 #2


    User Avatar
    Science Advisor
    Homework Helper

    Hi itryphysics! :smile:

    (The third equation gives you no extra information …

    it's just the sum of the first two equations …

    the number of independent loop equations is the same as the number of independent loops. :wink:)

    You've headed this "junction rule", but you haven't used the junction rule, only the loop rule.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook