00:01
Okay, we're supposed to solve this circuit using nodes or super nodes.
00:04
So there isn't really a super node.
00:06
A super node, you have to have a voltage source in parallel with a resistance, and that's not really going on here.
00:16
So i set this up to work with just doing it by the nodal method.
00:24
And so what i did, i put in a ground down here, and then i assign letters for the voltages at each node, and i put in unknown currents.
00:37
So here's the thing.
00:43
We've got four unknown voltages, but there's actually two currents that we don't know, or three currents actually, that we don't know anything about, i3, i5, and ix, all of which are important, and we can't define any of them directly, in terms of the voltages.
01:05
Well, i -x we can, but i -5 and i -3 we can't.
01:09
So we're going to end up with six equations with the four voltages and these two currents, i -3 and i -5.
01:23
So the first step is to write each of the other currents, not i -3 and i -5, in terms of the voltages.
01:35
So let's do that first.
02:01
So if you get i1, let's start here.
02:04
So we got v1 plus 2k times i1 and that equals v2.
02:26
I just get that from the loop law following along this branch from v1 to v2...