A very long straight wire carries current I. In the middle of the wire a right-a
ID: 2206235 • Letter: A
Question
A very long straight wire carries current I. In the middle of the wire a right-angle bend is made. The bend forms an arc of a circle of radius r, as shown in Figure P30.10. Determine the magnetic field at the center of the arc. (Use any variable or symbol stated above along with the following as necessary: ?0 and ?.) B = What is the direction of the magnetic field? into the plane of the computer screen left down out of the plane of the computer screen right http://www.webassign.net/pse/p30-10.gifExplanation / Answer
I'm assuming you want to find the magnetic field where the black dot is in the diagram. Working out the field due to the straights part of the wire is easy, it is as if there's one infinitely long wire carrying current I and distance r from the point where you want to find the B field. Working out the magnetic field due to the curved part of the wire is a tiny bit trickier, you need to use Biot Savart Law (give it a go). Finally you need to add the resultant B fields due to the straight & curved parts of the wire. Edit: I noticed your answer is correct only for the curved part of the wire, and I'm assuming you thought that the two straight parts cancelled out with each other, right? Well they don't. Use the right hand grip rule to see that they both produce a field in the same direction.