# 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
2
0
http://i615.photobucket.com/albums/tt237/chaz0426/Problem2.jpg

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
138
11
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.