00:01
Okay, so we're finally given a nice softball of a question in this chapter.
00:05
So we're told we have a 32 centimeter long solenoid, so the length here refers to the total distance from the first coil to the last coil.
00:15
And we know that we wanted to have a .3 tesla magnetic field and a maximum current traveling through it of 4 .5 amps.
00:23
So we want to know how many turns, so how many of these loops do we need for the solenoid for that to work? well, for solenoids, we know that the magnetic field is just given by mu not times the current, times the number of turns, and then divided by the length of the solenoid.
00:41
So this is just going to be a direct application of this equation.
00:45
So we want to solve for n the number of turns.
00:48
So we can just say that n equals the magnetic field times l over mu not times i.
00:56
So we want the magnetic field to be 0 .3 tuss...