Homopolar Motor

Wire spins with no visible gears or motor housing. Ask students to predict what will happen. Assemble so current flows through wire in magnetic field. Key idea: A current-carrying conductor in a magnetic field experiences a force that produces torque. Ask: Where are the motor's 'moving parts'? Safety and cleanup: Teacher-only; run a few seconds because wire/battery can heat; strong magnets require care. https://www.sciencebuddies.org/stem-activities/how-to-make-a-homopolar-motor