Help on this Circuit using nodal analysis?

Discussion in 'Homework Help' started by chaz0426, Apr 4, 2009.

  1. chaz0426

    Thread Starter New Member

    Apr 4, 2009

    it asks to solve for V1 and V2 using nodal analysis however I'm not sure how to solve this particular one because there is a voltage source and a resistor between the reference node and V1and I'm not sure what to do. Here is what I did so far because I'm not sure which way to go. I'm hoping someone can tell me which way is correct and why.
    What I did so far.

    equation 1: ((v2-v1)/1) = 2 + (v1/1) or ((v2-v1)/1) = 2 + ((v1+6)/1) " because of the 6v voltage source?"

    equation 2: ((v3-v2)/2) = (v2/1) + ((V2-V1)/1)

    equation 3: ((V3-V2)/2) + 3/0? or just + 3i?

    equation 1 and equation 3 is what i'm confused about.

    Also I just need V1 and V2 for the problem.
  2. vvkannan

    Active Member

    Aug 9, 2008
    If you have a resistor with a source between the reference and node you can convert it into current source parallel with a resistor (Here 80 A source and 3ohm).Another thing here is you can take v3 as 3 volts .
    Otherwise you have to include 6v in your node equations
    KCL at node 1

    (v1-6) / 1 + (v1 - v2)/1 + 2 =0

    at node 2 (v3 = 3v)

    v2 - v1 +v2 +(v2 - 3)/2 = 0

    Solving this we get the requireed voltages.