Description
‘Jumping Rings’ demonstrates Lenz’s law, an invisible force that tries to stop or counteract components. Many devices contain magnets. Lenz’s law comes into action when a magnetic field approaches a conductor, or coil of wire.
The exhibit features a copper coil with a magnetic ring on top. Pressing the button sends current through the coil, generating a magnetic field. This magnetic field opposes that of the ring. The coil and ring repel each other, causing the ring to jump up. This is known as Lenz’s law.
Electromagnets are used, for example, to quickly brake trains. When the driver activates the brakes, electromagnets under the train are switched on. An electromagnet is a magnet that can be turned on and off with electricity. The activated electromagnets create a strong magnetic field. The attraction of the magnet creates friction with the track, resulting in Lenz’s law and slowing down the train.
A lot of research is conducted on (electro)magnets because they operate efficiently and are usable in many applications. For example, in the healthcare sector to examine the body for diseases using an MRI scanner.
Why can a maglev train travel so fast?
- Press the button.
- This sends current through the coil.
- What do you see?
