Two long current carrying conductors are placed parallel to each...

Magnetic field in parallel wires is given by $B = \dfrac{{\mu}_{0}I}{2\pid}$

At midway, $\text{distance} = \dfrac{d}{2}$

$∵ \dfrac{{\mu}_{0}I}{\dfrac{2\pid}{2}} \times 2 = B$

$⇒ \dfrac{{\mu}_{0}}{\pi} \times \dfrac{2I}{d} = B$

$⇒ \dfrac{4 \times {10}^{- 7} \times 2I}{0 . 08} = 300 \times {10}^{- 6}$

$⇒ I = \dfrac{3 \times {10}^{- 4} \times 0 . 08}{2 \times 4 \times {10}^{- 7}} = 30A$

As ${B}_{net} \ne 0$, so the wires are carrying current in opposite direction.