00:01
Hello students so in this question we have this arc here so we have an arc bc and d and then we have two small straight lines that is cd and ab now the angle between the arc bc and d is given to be equal to 120 degree that is equal to 2 pi by 3 radian and it said that the current flowing to this whole loop is equal to 11 .5 ampere.
00:46
We need to find out what is the net magnetic field at point p.
00:50
So given that radius of arc bc is equal to 30 centimeters, 0 .3 meters.
01:07
Similarly, radius of arc, da is r2 that is equal to 20 centimeters, that is equal to 0 .2 meters.
01:24
Now we know that the magnetic field at a particular point due to a current carrying arc, the magnetic field due to a current carrying arc is given by the expression b is equal to mu not 4 pi, mu not i theta divided by 4 pi multiplied by r here.
02:04
And the value of current is given to us.
02:06
So using the value of current, now we're going to find out what is the total net magnetic field at point p so we can say magnetic field at p due to arc bc that is b1 would be equal to so it's mu not i theta so it's mu not i is 11 .5 theta is 2 pi by 3 whole divided by 4 pi multiplied by r here is 0 .3 this is in 10 .3 this is in 10.
02:50
Tesla.
02:54
So it's simply equal to, so this would be equal to mu not multiplied by 11 .5 multiplied by 1 divided by 6 whole into 0 .3 tesla.
03:24
Just canceling this to itself, we get this to be this much.
03:29
And this comes down so it becomes 6.
03:32
So on putting the value we get mu not is equal to how much that is equal to 4...