00:01
All right, so we have a circular loop that has a radius of 8 centimeters, so 0 .8 meters.
00:09
And it's placed in a magnetic field that has a strength of 0 .8 tesla.
00:13
And so we want to know when the plane of the loop is perpendicular to the field lines, kind of like this.
00:20
We want to know what is the magnetic flux through the loop.
00:26
So it calls part a.
00:27
So the magnetic flux, we'll call it phi, is going to be b times.
00:31
The area of the loop times the cosine of the angle between them.
00:36
But here, this is the cosine between b in the normal vector.
00:40
We'll call this in hat.
00:41
So for the first case, the normal vector in the b field are parallel.
00:45
So we don't have to worry about any cosines because the cosine of zero is one...