일반물리학 2 — Magnetic Fields Due to Currents: Problem 51

51 In Fig. 29-56, two long straight wires (shown in cross section) carry the currents \(i_1 = 30.0 \text{ mA}\) and \(i_2 = 50.0 \text{ mA}\) directly out of the page. They are equal distances from the origin, where they set up a magnetic field \(\vec{B}\). To what value must current \(i_1\) be changed in order to rotate \(\vec{B}\) \(25^\circ\) clockwise?