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## Homework Statement

The attached figure shows, in cross section, two long parallel wires that are separated by distance d = 18.6 cm. Each carries 4.34 A, out of the page in wire 1 and into the page in wire 2. In unit-vector notation, what is the net magnetic field at point P at distance R = 34.2 cm, due to the two currents?

## Homework Equations

B = iμ

_{o}/2∏R

## The Attempt at a Solution

(1) The magnetic field lines around wire have a counterclockwise direction. The magnetic field lines around wire 2 have a clockwise direction. When the field lines hit point P, those from wire 1 point to the top right while those from wire 2 point to the bottom right.

(2) Angle a in the diagram is equal to the tan^-1 of 9.3/34.2. Therefore, it = 15.21. This is also the measure of the angle (measured from the x axis) of the tangent of the magnetic field lines at P from both wire 1 and wire 2.

(3) Bnet = 2[iμ

_{o}/2∏R] = 4.79 x 10^-6 T.

(4) However, only the x components of the magnetic fields survive and add. The y components cancel. Therefore, we must multiply the Bnet by cos(15.21), which yields 4.62 x 10^-6 T.

(5) Because the total net field points to the right, the answer is (4.62 x 10^-6 T)(i hat)

Is this right? I can't find the answer to this question anywhere. Thanks!