00:01
In this problem, we have been given that there is a toroid and that toroid has 400 tons of wire and the radius of this toroid is 6 centimeters.
00:14
So we can take the radius as 6 into 10 raise to minus 2 meters.
00:18
And the current that's flowing through the turret, that's 0 .25 amperes.
00:24
So we need to determine here the magnetic field in the core.
00:28
So the expression to get the magnetic field in the core of a doroid, that's basically mu not n i divided by 2 pi r.
00:39
So here one thing is to be observed that this is the magnetic field when the material is air.
00:46
But here we have the permeability of the core given as 80.
00:53
That means this is the value of mu r.
00:56
So we can say that the magnetic field, because of this.
00:59
Core that will be mu not times 80 into n i divided by 2 pi r so when we put here the values we get 4 pi into 10 raise to minus 7 as the value of mu not we multiply that with 80 times the number of terms and that multiplied with 0 .25 and divided by 2 pi into the radius which is 6 into 10 to minus 2.
01:29
So this anyways gets cut and we have 2 here.
01:32
So when we multiply the numerators without including the powers of 10, so we get 64 ,000 and that multiplied by 0 .25...