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: Node Voltage Analysis

  1. Feb 21, 2015 #1
    1. The problem statement, all variables and given/known data

    Determine the three node voltages, va, vb, and vc, when all the conductance's are equal to 1S
    Circuit Diagram:

    The labels are a bit cut off, hope you guys can see it. The current source parallel with G2 is 3A

    2. Relevant equations

    3. The attempt at a solution

    I think their is a mistake in their solutions to the equations
    These are my equations:

    Node A:
    Va(G1+G2+G6) - G2*Vb - G6*Vc = 9-3
    Node B: -G2*Va + Vb(G2 + G3+ G4) - G4*Vc = 3
    Node C: -G6*Va - G4*Vb + Vc(G4 + G5+ G6) = 7

    These are the textbook solutions:

    Node A:
    Va(G1+G2+G3) - G2*Vb - G6*Vc = 9-3...........................How is G3 included when it is part of node B ?
    Node B: -G2*Va + Vb(G2 + G3+ G4) - G4*Vc = 3
    Node C: -G6*Va - G4*Vb - Vc(G4 + G5+ G6) = 7..................How did they get -Vc ?

    My main question is, Is the textbook correct, If yes, then why ?

  2. jcsd
  3. Feb 21, 2015 #2


    User Avatar

    Staff: Mentor

    Your equations look fine. It looks like you've caught an error in the text.
  4. Feb 21, 2015 #3
    That's what I thought, thanks :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted