Point $P$ is midway between two long, straight, parallel wires that run north-south in a horizontal plane. The distance between the wires is $1.0 \mathrm{~cm}$. Each wire carries a current of $1.0$ A toward the north. (a) Find the magnitude and direction of the magnetic field at point $P$. (b) Repeat the question if the current in the wire on the east side runs toward the south instead.