 This video we're going to look at finding series sections in a combination resistor circuit, meaning that there's both parallel and series sections in the circuit. One of the keys to making sure that you've got a series section is by looking at the junctions. And here I just have typed out that a junction has three or more wire segments. So over here I've got a junction because I've got one, two, three wire segments. Here's another junction, which again has three. Here's a junction and here's a junction. And on this particular circuit diagram they actually show those junctions as dots. Now there can be a corner like I've got up here, but it's not a junction because there's only one, two wire segments. It's just a wire that's bent and not an actual junction. So now when I start looking at my actual paths I want to be able to figure out where do I have two resistors along the same path without any junctions in between them. So if I go along this path, that path has two resistors on it and there's no junctions between those two resistors. But if I were to look at this path, that one is not series because there's a junction in between those two resistors. So I can't treat R1 and R6 in series at this point, but I could treat 3 and 4 in series. Now just to give you a little bit of more examples, here's another one. And again they've got the junctions shown in there. Sorry, got to adjust where my stuff is here. Again my junctions are going to be shown in individual locations where I've got two or more wires coming together. So there's a junction, here's a junction, here's a junction, and here's a junction. And in this particular one I've got two different sections which are already in series. And that would be my segment here where I've got two resistors without a junction in between them. And here where I've got two resistors that don't have a junction in between them. This circuit also has some nice clearly labeled junctions and a lot of parallel sections but here's a section where we actually have a junction that turns, or not a junction, a series section where it goes around a corner so they're not in a straight line from each other but they are on the same path because there's no junctions in between them. Now when you get a circuit like this one it doesn't have the junctions marked but you can look at it and say up here's three wires, that's two wires, it's okay. Here it's just a corner again, up here's a junction and here's a junction, here's a junction, and those are my only junctions. So when you look along you can actually see that this section here is actually showing me a series where I've got these two right next to each other with no junction in between them. So that's a little bit more about finding series sections when you're looking at one of these complex circuits and this is just a first step at looking at your circuit.