Biot-Savart Law with Projector Circuits and Metal Filings
![4 glass casings with metal filings in them connected to a power source](/media/libraries/college-of-science-and-engineering/physics/images/demo-images/biotsav4.jpg)
PIRA 5H15.10
Use the projector circuits shown at left to show magnetic field lines produced by a variety of current carrying wires. The 12 V DC battery eliminator shown provides enough current to align metal filings placed on the glass plates that bisect the circuits. Show this on an overhead projector so a large class can see. Do not have the power on for more than two minutes. The wires will get very hot.