nodal analysis

[potchi]

Hi I'm having a hard time solving for this problem using nodal analysis. Although I already answered the problem using mesh analysis. I have to verify the answer using nodal analysis solution. My main problem is on how to source transform the voltage source in this circuit and what would be the resulting circuit after applying source transformation.

This is the transformed circuit. Find V2(S)/V(S) using nodal analysis.

 

[Laplace]

The description given is confusing. You say, "This is the transformed circuit." What was it transformed from? As shown it is set up for either node or mesh analysis. For mesh analysis you would use the loop currents shown, summing the voltage drops around each loop and obtaining 3 equations. For nodal analysis you would use the voltage nodes, recognizing that the V(s)+ node is a dummy node while the V(s)- node is ground. Sum the node currents for nodes V1 and V2 (treating the dummy node as though it were a real node with the nodal constraint that the node voltage is forced to equal Vs), obtaining 2 equations. Using the dummy node method will automatically make the source transformation in the other 2 node equations without changing circuit topology. Then combine the two equations to eliminate V1(s). Of course, if you have a circuit with multiple voltage sources and no common ground, then it can get pretty complicated.