All right, well as I'm sure you all have learned in class, but when you have a wire with a current flowing down it, it's going to create a magnetic field around that wire. What we're going to do today is we're going to have two wires with current flowing through them that are going to be very close together, and there's going to be a force between them. And we're going to investigate that force. And we're going to use the equation. The force is equal to IL, plus B. What I is the current traveling down the wire, L is the length of the wire, and it also contains which direction the current is flowing. And B is obviously the magnetic field. OK, so the equivalent we're going to be using today is first we're going to have to use this special power supply that we use to generate or regulate a current that goes into the experiment. Then you should all be familiar with our digital multimeters. Because of the way everything is set up, we can't use it to measure the current going through the system. So what we're going to do is we have a little resistor in this box. We're going to measure the voltage drop across the box and use that to calculate the current that's going through the system. Next, we have what we call a current balance. As you can see, there's a little mirror here. There's also a lot of knobs. If you can use these knobs on either side to adjust the distance, the R out here is from here. And you can try and line up exactly where they should be. You can also adjust how well everything is balanced using these two knobs on the pad here. Then also we have a mirror, which we'll get to in a second. Then we also have all these fun little weights that we're going to get to use. All right, so over here we have the masses that you're going to be using today. An important note about the masses is when you're using them do not use your fingers to handle them. Instead, use the tweezers that are contained within the boxes. And then when you use the masses, you're going to pick them up and you're going to put them on the little tray on the top wire. So over here we have the laser that we're going to be using for this experiment. Remember the mirror we talked about earlier? The way this is going to work is we're going to bounce the laser off the mirror and then onto a backstop that will set up wherever the laser is hitting. Then we can mark where the beam is hitting on the backstop so we can perform the experiment. A quick note about the laser is although these lasers probably won't bind you, it's still possible. So make sure you always know where your beam's going. And if you need to pick something up off the ground, cover your eyes before you bend over. All right, so as you can see, we have everything set up. And you'll notice that the laser point is fairly stable right now. It doesn't appear to be moving much if it all. And then also on our readout of our voltage, we have 0.35 millivolts. So not a lot's going on. We also have our power supply set to zero roughly. So if we go ahead and we increase the current flowing through the waters, we can see the point start to move quite drastically, actually. And not only that, but if we look at our multimeter, we can see that we're now getting 144 millivolts or 141.