Question

Two round concentric metal wires lie on a tabletop, one inside the other. The inner wire has a diameter of 23.0 and carries a clockwise current of 20.0 , as viewed from above, and the outer wire has a diameter of 38.0. What must be the direction (as viewed from above) of the current in the outer wire so that the net magnetic field due to this combination of wires is zero at the common center of the wires? What must be the magnitude of the current in the outer wire so that the net magnetic field due to this combination of wires is zero at the common center of the wires?

Answer 1

Answer:

I = 33.04A

Explanation:

The magnetic field at the center of a loop of wire is proportional to the current flowing through the wire and inversely proportional to the radius

So therefore we have:

20/23 = I/38.0

We then solve for I

cross multiplying we have 20 x 38 = 23 x I

I = 20 x 38/ 23

I = 33.04A