GATE2019 EC: 36

Question

• A.
• B.
• C.
• D.

Two identical copper wires $W1$ and $W2$ placed in parallel as shown in the figure, carry currents $I$ and $2I$, respectively, in opposite directions. If the two wires are separated by a distance of $4r$, then the magnitude of the magnetic field $\overrightarrow{B}$ between the wires at a distance $r$ from $w1$ is

• A. $\frac{\mu_{0}I}{6\pi r}$
• B. $\frac{6\mu_{0}I}{5\pi r}$
• C. $\frac{5\mu_{0}I}{6\pi r}$
• D. $\frac{\mu_{0}^{2}I^{2}}{2\pi r^{2}}$