The wires in a household lamp cord are typically 3.0 mm apart center to center and carry equal currents in opposite directions.
If the cord carries current to a 100-W light bulb connected across a 120-V potential difference, what force per meter does each wire of the cord exert on the other? (Model the lamp cord as a very long straight wire.)
Is the force attractive or repulsive?
Is this force large enough so it should be considered in the design of lamp cord?