Grainger CEME

Professor Arirjit Banerjee presented “Electromechanical Energy Conversion = Magic” this past December to the Campus Middle School for Girls physics class taught by Laura Shoener. He first talked about energy production—35% goes to consumption and the rest to generation, and then explained the concept of horsepower (including a picture of a horse). He and the girls shared common examples of energy consumption and the unexpected: a party-light rotating ball and catapult used to launch planes from an aircraft carrier. Arijit described how motion produces electricity and electricity produces motion. The magic comes with magnets. He demonstrated linear motion with iron shavings moved by a magnet on a plastic sheet. And when copper is pulled through the opening in the red magnet on the table, it creates an electric field through the copper. The girls could feel the force but only when the copper was moving. He cited Farady’s law on changing electric fields and Olm’s law on voltage through a conductor and explained how we need rotation to produce power.
Arijit created sine waves exhibited on an oscilloscope he hooked up to a magnet controlled with an electromagnet. The class then went upstairs to the Grainger Electric Machinery Laboratory and experimented with the magnetic ring cannon.