Magnetism

Join Jared as he introduces Magnetism, and explains why it’s closely related to electricity!

Whereas electrons are simply negative charges, magnets have two poles; a North and South end. The Earth is actually a giant magnet, and the magnetic poles are where the north and the south pole are, so we call the magnets’ ends north and south poles, too.

What happens when you bring two magnets together? If one magnet’s North end is facing the other’s South end, then they attract one another! In Jared’s first video, the rings stick together when opposite ends of each magnet are aligned. By contrast, when the same poles are facing one another, the magnets repel. Jared can get a magnet to hover in air, using this magnetic repulsion!

In the second video, Jared explains how we can use electric current to make a magnet! A current of moving electric charges, as in the coil of wire, creates a magnetic field. When this coil of wire is wrapped around iron (or any other magnetic material), the iron acts as a magnet! In the video above, when Jared turns on the power, Alternating Current (AC) flows through the wire. This creates an alternating magnetic field! A ring magnet flips up and down in such an alternating magnetic field.

Just as a current of moving electric charges creates a magnetic field, changing magnetic fields can also induce an electric current! In this third video, Jared brings out a coil of wire with a light-bulb attached. When the magnet is on, he can make the light-bulb shine just by moving the wire through the magnetic field (without even touching anything)!

Finally, Jared brings out a metal ring, and shows what happens when he turns on the magnet! When Jared turns on the power, the magnet creates a magnetic field. This magnetic field induces a current in the complete ring (whereas the ring with a gap doesn’t allow electrons to move in the full circle). The induced current creates an opposite magnetic field, and the ring flies off!