1. The problem statement, all variables and given/known data In a current-carrying wire, the total net charge in the metal is zero. Why does the wire experience a force when placed in a magnetic field? 2. Relevant equations 3. The attempt at a solution The reason for the force is the motion of the electrons, not their charge as such. i.e. it's a relativistic effect due to their motion. The current travelling in the wire creates its own magnetic field which interacts with the external one. Depending on the relative angles of the fields, there will be a resulting force acting on the wire.