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: 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