# Homework Help: Node Voltage Analysis

1. Feb 21, 2015

### TheRedDevil18

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 ?

Thanks

2. Feb 21, 2015

### Staff: Mentor

Your equations look fine. It looks like you've caught an error in the text.

3. Feb 21, 2015

### TheRedDevil18

That's what I thought, thanks :)