 Now we can look at question three on the back side of the sheet. And this now has to do with the direction of the magnetic field for a current carrying loop. And remember for our special case equation, we're finding the magnetic field at the center of the loop. So I've marked that as point P right there at the center. Now again, like we had on the front side, we're going to be able to use our right hand thumb rule. The difference is, is rather than having a single direction, I'm going to have to actually turn that thumb as I go around different parts of the circuit. So now I'm going to take my thumb and I'm going to put it over here and I'm going to rotate it just a little bit to line up with the current over on this side. What I see is that over here on this left side, I've got the magnetic field coming out. And then it crosses over the wire and here on the right side is going in. If I were to move up towards the top of the circuit, again I have to rotate my thumb until the current continues to go around it. And I see above it's going to be coming out and then it loops over and it's going to go into the page down here below the wire. And I can continue to do this all the way around the loop, but I've got to actually turn it and get it aligned as I'm going around. But what you might notice is that even though left, right, up, down, where it comes in and out are different. Over here at point P is the side where it's going in. Around the loop, the magnetic field was coming out. It's kind of like imagining a bunch of individual discrete little loops going around the wire. And it turns out that all of them go out and then come back in at point P. So for this particular loop at point P, the magnetic field is going into the paper. Now real quick I'm going to show you what's not on the worksheet, but what if I reversed the current. Now I did that just by flipping my diagram so it flipped the P as well. I don't want to flip my thumb to be a left thumb, but I do need to rotate it around then. And in that case, when I line it up with the current, I would see that the magnetic field is actually coming out of the paper in the center and then going back into the paper around the loop on the outside. So that would be the case if the current was going in the opposite direction around the loop. But we have our loop where the current is going clockwise. And for that clockwise current loop, you should be able to see that if I line my thumb up with the current, it comes out here and goes in over there.