00:01
This problem uses kerchhoff's current law, which says that for any node, the sum of the current's end is equal to some of the currents out.
00:11
And kirchhoff's voltage law, which says that the sum of the voltages in any closed loop is equal to zero.
00:18
And of course, holmes law, which says that voltage is equal to current times resistance.
00:23
So here i have the general layout of the circuit and i've labeled the nodes, a, b, c, d, and e, and the loops, one, two, three, and four.
00:33
And i'm just going to start with loop one, and i'm going to do kirchhoff's voltage law.
00:41
And i'm going to be working my way around clockwise.
00:46
And there i have minus 6 volts plus i sub 1 times one kilo -oam.
00:54
And that's just, i assume that it's going downwards.
00:57
If i'm wrong, the math will tell me and i'll get a negative answer.
01:01
And then i have minus 6 volts, and all that equals to 0.
01:07
And therefore, 1 kilo -oam times i -1 is equal to 12 volts.
01:14
And that means that i -1 is equal to 12 millamps.
01:20
So then i'll look for another place i can use that.
01:24
That and plug it in then.
01:28
Kirchhoff's voltage law here at loop 3...