Question

Two wires, each having a weight per unit length 10^-4 N/m, are parallel, with one directly above the other. Assume that the wires carry currents that are equal in magnitude and opposite in direction. The wires are 0.1 m apart and the sum of the magnetic force and gravitational force on the upper wire is zero. Find the magnitude of the current in the wires. (Neglect the Earth's magnetic field)