 In this video, we're going to go through what happens when we have some inductance in a circuit. So this inductor here, resistor in the circuit. So we'll use the coils resistance and a capacitor in the circuit. So that's going to change things up. And we've also got this little ammeter down here. We'll talk a little bit about that later on down the road. Now here I go, I've assigned some values. I've given this inductor an inductance of 300 millihenries. And it's got a coil resistance of 75 ohms. And this capacitor here we've said is 100 microfarads. So what we're going to do is we're going to see what happens, how we're going to step-by-step process through this, and what happens to the current. And we're going to be looking for what is the Z of the circuit. So we're going to look for the total circuit impedance, total circuit opposition to current flow. We're going to talk about the inductive reactance. So we're going to change this millihenries into an XL, which is an ohmic value. We're going to take this bad boy here and we're going to turn it into an XC. And then we're going to talk about Xnet. I'm going to talk about that in my next little slide here. But what Xnet is, is you figure out what your XL is, and you figure out what your XC is, and then you subtract them from each other. Now what's happening is this guy, let me just draw a little picture for you. This guy right here, make sure I've got the right color. He's going up. He's got a reactance. So he's going to be heading straight up this way. Now the capacitor though, what it does is it creates reactance too, but it is 180 degrees out of phase, and that'll be covered or has been covered in another video. So it's going the opposite way. So if you notice these guys are 180 degrees out of phase, it means that if this guy goes up, this guy right here pushes back down on it. So we get what's called a net reactance, which is what we're going to calculate over here. Then we're going to look for our theta of the circuit. So what's our phase angle and what is the power factor of the entire circuit? Let's take a look at the formulas we're going to be using for this walkthrough. At this point, you should be familiar with a few of these. We've got the XL is equal to 2 pi FL. So that's your inductive reactance. Now this guy here, this is your XC, your capacitive reactance. It's 1 over 2 pi FC. So it's the inverse. So it's the opposite of the inductance, but you're using the capacitance, not the inductance. Then our X net, I was talking about how it's XL minus XC, and then our power factor. Now I've got power factor right now written down as resistance over impedance. Technically, that's not true. Technically for power factor, when we're talking about power factor, it is watts over VA. But in a series circuit, you can use the same thing because they're similar triangles. So we're going to use, build an impedance triangle. So we're going to use the resistance over the impedance for our power factor. And with that power factor, we're also going to be able to get our theta just by inverse cosing that power factor. So let's take a look at our next slide here. Now in our next slide, we've got all our values here. So what I need to do is I need to take this guy and convert it to an XL and this guy here and convert it to an XC. And through the miracle of modern technology, there you have it. Instead of 300 millihenries, now I have an XL of 113 ohms. Instead of 100 microfarads, I have an XC of 26.5 ohms. So we've got those guys written in over here, 113, 21.6. Now when we're working out our Xnet, our Xnet is just going to be 113 minus 26.5 to get our net reactance, it's called. Boom, there you have it, 86.5 ohms. Now with that in mind, we also have this resistance. So we're going to build ourselves an impedance triangle. When we build this impedance triangle, we're going to use the resistance on the bottom of the triangle like we always do, but then we use, before we were using either our XL or our XC depending on which circuit you're looking at, now we're going to be using the Xnet because these guys are working against each other. So we have to use the Xnet. So let's take a look at our triangle now. God bless the triangle, here it is. 75 ohms on the bottom. Resistive element always goes on the bottom. 86.5 ohms on the side, that is your net reactance. We're going to take this squared plus this squared equals this squared and we get our overall impedance of 114.5 ohms. So that is our total opposition to current flow in this circuit. God bless Pythagoras. So here we go. We worked out what our XL was. We worked out what our XC was. We subtracted our XC from our XL to get our Xnet. We went ahead and we used 75 ohms and our Xnet to determine what our Z of the circuit was. So we put this over here, and I know I didn't ask for it, but for poops and giggles I gave it to you anyways. 120 volts divided by 114.5 ohms gives you a line current of 1.05 amps, which leaves us with two more things to figure out. We've got to figure out the theta of the circuit and the power factor of the circuit. Okay, here's our triangle again. Now in order to figure out the power factor, I know I asked for the theta first, but let's talk about the power factor first. Power factors are over Z, so I've got my R here and my Z here. Well, this is my adjacent over my hypotenuse. So I'm going to show you a little trick in a second here. Power factor, let's work that out. 75 divided by 114.5 gives us a power factor of... It works out on your calculator to be 0.655, but we turn that into a percent, so it's 65.5%. Now here comes the cool thing. I love using COS, which is basically all that is is your power factor because it's adjacent over hypotenuse. So I take this guy, that 0.655. I'm going to inverse COS that to get my angle. What? It's that easy. So all you have to do is you inverse COS this guy, the 0.655. Don't plug in 65.5, because we're going to go back to the decimal number that it is. 0.655 inverse COS, and we get our angle, which is 49 degrees, y'all. So we've got our power factor at 65.5%. Our phase angle is 49 degrees. We basically figured out everything on this walkthrough. Let's take a peek back at our circuit. So there we go. We've got our phase angle here, our theta of the circuit there, our power factor of the circuit there. Now you notice that I say this is lagging. Lagging. That's because we have more inductance, or inductive reactance, than we do capacitive reactance. So there's more inductance in the circuit. That's very important. So whenever you have more inductance in the circuit, it is a lagging power factor. Your current is lagging your voltage. That's very important. Now I did not go over what the voltage was across the coil. I did not go over what the voltage was across the capacitor. That's covered in other videos, but just as a quick refresher, you're just going to take the current, which was at 1.04. Didn't show up there. And we're going to multiply it by the impedance of this guy. So you're going to build a little impedance triangle for that coil. If you want to figure out what the voltage is across the capacitor, it's the current times the reactance there, and you're done. And then you can go into powers and all that sort of stuff as well. I just wanted to go through and show about net reactance in this video just to get our head wrapped around that. Thank you.