A horizontal current-carrying wire, free to move in Earth’s gravitational field, is suspended directly above a second, parallel, current-carrying wire. (a) In what direction is the current in the lower wire? (b) Can the upper wire be held in stable equilibrium due to the magnetic force of the lower wire? Explain.I assume they travel in opposite directions if they are both charged the same, but I think my instructor wants something more specific. Any help is much appreciated.
Current carrying wire does not have extra charge but only flow So there is no electrostatic force between them. The magnetic force is present only when current flows through both wires. If it flows in the same direction then they attract. So if the lower wire is fixed and you wish to suspend the above it must repel it to overcome the gravitational force due to earth acting on it. Hence the wires must carry currents in opposite direction.
