00:01
In this problem, we're given information about a coil, and we want to figure out what the current through the coil is if we know the maximum amount of torque on it.
00:12
We learned from our book that the amount of torque acting on a coil in a magnetic field is given by the number of turns in that coil, the current going through that toil, the surface area that the coil makes, the magnetic field that the coil is in, and multiply that by sine of phi, or the angle between the normal of our coil area and the normal to our coil area and the magnetic field.
00:42
So we're told in this problem what the maximum torque that this coil experiences.
00:48
Well, the maximum torque, if we look at this expression, the torque maximum is going to occur when phi is equal to 90 degrees, right? because if phi is 90 degrees, then sine of phi, which is sign of 90 degrees, is 1.
01:05
And remember, our sine function can vary from 0 to 1.
01:09
So if we want our twerk value to be the largest it can be, we want our sine phi value to be the largest it can be.
01:17
Right.
01:18
So we're going to get an expression for the maximum torque that this coil is going to feel when we have a phi of 90 degrees plugged into sign, and that just means that's going to go to one, and we have an expression of n -i -a -b that gives us the maximum torque the coil experiences...