# Equal currents are flowing in three infinitely long wires along positive x, y and z directions. The magnetic field at …..

Q. Equal currents are flowing in three infinitely long wires along positive x, y and z directions. The magnetic field at a point (0, 0, -a) would be (i = current in each wire )

(a) $\displaystyle \frac{\mu_0 i}{2\pi a} (\hat{j}-\hat{i})$

(b) $\displaystyle \frac{\mu_0 i}{2\pi a} (\hat{i}-\hat{j})$

(c) $\displaystyle \frac{\mu_0 i}{2\pi a} (\hat{j}+\hat{i})$

(d) $\displaystyle \frac{\mu_0 i}{2\pi a} (-\hat{i}-\hat{j})$

Ans: (a)