
The magnetic field \( B \) at a point midway between two parallel currents in opposite directions is:
\[ B = \frac{\mu_0 I}{2 \pi a} \times 2 = \frac{4 \pi \times 10^{-7} \times 10}{\pi \times (2.5 \times 10^{-2})} \] \[ = 16 \times 10^{-5} = 160 \, \mu T \]