00:01
Okay, we have a loop of wire that has a current in it.
00:07
Given the circumference of the loop of wire and we have a magnetic field that is directed parallel to the plane of the loop and we want to know the torque.
00:17
So essentially we have this loop of wire and there's a current running in it.
00:29
Some current.
00:32
And then we have the magnetic field.
00:39
Which is directed parallel to the plane of the loop.
00:49
So like this.
00:51
And we're not told directions of magnetic field or directions of current.
00:58
So we just are worried about magnitudes here.
01:02
So what is the torque? well, i've seen many different equations.
01:09
But this is the one.
01:11
That i like to use they all end up being the same anyway so the equation is torque equals the magnetic moment magnetic dipole moment sorry which is given the symbol meu crossed with the vector b which is the magnetic field so the magnetic moment b is defined as the number of loops of wire times the current, let's see i used a lowercase i, times the current in the loop, times the area of the loop, and then times the normal vector.
01:54
For this, the magnetic field is perpendicular to the plane, or it's parallel to the plane of the wire, but it's perpendicular to the normal vector of the wire loop.
02:11
So the area of the area.
02:13
Vector, the normal vector of this loop, would point directly out towards you...