00:01
All right, so let's say we have four wires with equal currents, but in different directions.
00:05
So the bottom two are going into the page, the top two are coming out of the page, and the current, the magnitude of the current in each of them is 7 .8 amps.
00:13
I want to find the magnetic field at this location as a vector.
00:18
So the field from the top wire at this point will be pointing this way.
00:21
The field from the other one will be pointing this way.
00:24
And then the field from the bottom wire is basically going to be pointing in, you know, they'll provide equal contributions that look the same.
00:32
And so really, at this point, you can see the horizontal components are going to cancel.
00:36
All we have to do is compute the vertical components.
00:40
And so b is going to be equal to mu not times, you know, for an individual wire, let's just say this is mu not over 2 pi r...