By Julia Pfeiffer, Blackheath High School, London
What is an electromagnet and how it works?
An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The poles of an electromagnet can even be reversed by reversing the flow of electricity. An electromagnet works because an electric current produces a magnetic field. The magnetic field produced by an electric current forms circles around the electric current. Normally, the atoms in something like a piece of iron point in random directions and the individual magnetic fields tend to cancel each other out. However, the magnetic field produced by the wire wrapped around the core can force some of the atoms within the core to point in one direction. All of their tiny magnetic fields add together, creating a more powerful magnetic field. As the current flowing around the core increases, the number of atoms which are aligned increases and the stronger the magnetic field becomes. Eventually, all of the atoms that can be aligned will be aligned.
How the device works:
The reason why I think everyone assumes levitation could never work is because essentially it has always been thought of as the device having to make force from nothing, and enough force not only to get off the ground and ‘defy’ gravity but also to support the thing it is making levitate. The definition of levitation is: ‘To float in the air, defying gravity’. It is also said to be to, ‘to cause something to float as if by magic’. So therefor in order for a levitation device to work it would need to use non-contact force(s). My prototype uses magnetism because it can be directed in any way and all force goes in a continuous self sustained loop of force. Into each other and out at each pole because of the repulsion of the similar poles (N and N/ S and S) and the attraction of the opposite poles (N and S/ S and N). The formation of electro-magnetic shapes means that all force will be utilised and sent in the direction needed.
My device is made up of three major components:
1. The (two) ring magnets attracting the (four) horse shoe magnets
2. The ring magnets repelling each other
3. The horse shoe magnets repelling each other
(this is demonstrated in the diagram at the top of the document)
The ring magnets which are located in the centre of the horse shoe magnets and are one pole for example North and the horse shoe magnets which are place at four equal points with their curves facing outwards are another pole for example South. The ring magnets are needed for stability as the force generated by the ring magnets will repel them from each other but still attract the horse shoe magnets meaning the horse shoe magnets wouldn’t just fly apart in various different directions. Instead they insure that everything is held securely together enabling for the device to be stable enough for levitation to take place; all the magnets will be compact and generating high amounts of force in focused and specific directions.
What sets it apart?
The reason why I feel that levitational mobility as a whole could be revolutionary is because it is far faster than any other known or conventional ways of mobility if applied correctly. This is because it evolves zero friction with the ground and the device itself potentially enabling faster speeds than ever before. However what sets the device I have come up with apart from all of the other currently used devices is that it does not require both magnets on the floor and the levitation device itself in order to work. Instead it singularly uses the force from the device itself meaning it can hover on any terrain. This making it much more useful and versatile than any other existing levitation devices. I believe that with my invention and it being executed correctly the possibilities could be endless and possibly even the way we look at transport and the world changed.
Article title: Questions and Answers - What is an electromagnet?
Website title: Education.jlab.org