00:01
Okay, so we're looking at question twenty eight point twelve.
00:04
We have to parallel wires that are five centimetres apart, so each one is going to be two and a half centimeters from this point.
00:14
Pain, um, and we have currents in each of these wires.
00:21
The first current is going is twelve amps going to the right and then the bottom wire is twenty four amps moving to the left and were asked to find the magnitude and direction of the magnetic field at point peak.
00:37
So let's first start thinking about the direction of the magnetic field.
00:41
So, looking at the top wire here, we see that the field is pointing to the left to the right.
00:49
And so, using the right hand rule, if we point our thumb in the direction of the current than our figures are going to curl into the page at point p.
00:59
So the magnetic field is pulling into the page from this top current from the bottom current that's moving to the left again.
01:08
If you use the right hand rule, we point our thumb in the direction to the left and then our finger they're going to curl into the board so again at point p, that's causing a current directly straight into the page.
01:23
So that's the direction.
01:24
And that's convenient because it means we're going to be able to simply add the magnitude of the current from of the magnetic field from each of these two wipers.
01:34
So to find the magnetic field from a segment of current, we need to use the beyonce of our law, which is i've been right up over here.
01:45
So the magnetic field is going to be you, not over for pie when our constant you not, and then the current thief segment of length of the wire and then sine of the angle here, this angle file, this is the angle that we're gonna want.
02:03
We want the angle between the current and the direction, uh, pointing to the point that we want ah, and then our is going to be the actual distance.
02:14
So that's going to be our eight centimeters here.
02:17
So going through implying this and let's just do this for wire one.
02:23
So that's hop current appear of twelve hams, so copying our equation over here we have the current, uh, in this case is going to be twelve ants b d l that we want to use...