00:01
Okay, in this question, we're asked to find magimatic field at point p created by a small current element, which is near the origin.
00:09
And we're told that the length of the current element is 0 .5 millimeters, and that the current is 540 amps.
00:17
So we're given the position of point p, and yeah, we just need to find the magnetic field there.
00:24
So the formula for a magnetic field created by current element is mu not over the magnetic field.
00:31
Over 4 pi times the integral of i d l hat cross r hat over r squared so we have all the pieces we need here the trick is just figuring out this cross product so i is given to us d l is given to us we've also got to find out what r hat is and what r is so r is just the direction or r -hat, i should say, is the direction from the origin to point p, and r is the length of the vector.
01:10
And we know that r -squared is equal to x -squared plus z -squared.
01:19
So r is going to be the square root of that.
01:24
So we can plug that in, and then r -hat is just the direction of this.
01:29
So we can just divide the vector by the magnitude.
01:35
So we have those parts, and now we just need to do this cross product.
01:40
So the current element is in the j direction.
01:45
So we're going to set up a cross product...