There are many ways to use a magnetic disc. To illustrate their applicability, here are a few examples:
Closure for a bag or purse
Magnetic discs can be used as closures for bags and purses. They are used to hold the bag closed by attracting the metal of the clasp on one side of the opening to the magnet on the other.
Planning events
Planning magnetic discs can be used on whiteboards for planning events as they allow different pieces of paper to be held onto a whiteboard in a colour coded system.
Fridge magnets
In addition, basic and planning magnetic discs can also be used to decorate fridges due to the large array of different colours and shapes available.
Computer memories
Small ring magnetic discs, called ferrite cores, are used in some computers as a magnetic memory. Each core in a computer relates to a single bit of information.
Magnet therapy
Basic magnetic discs are used in magnet therapy. They are considered to be a help to ease migraines, breathing, hand and feet problems, however there is no scientific evidence to support this.
Speakers
Ring magnetic discs are used in speakers to help produce sound waves. There are always two magnets in a speaker, an electromagnet (known as the voice coil) and a ring magnetic disc. The north pole of the electromagnet is attracted to the south pole of the permanent magnet (and the other way around).
When the electromagnet’s polar orientation switches (and the north and south poles switch sides), due to the electricity of the speaker being turned on and off, so does the attraction and repulsion between the electromagnet and permanent magnet.
The alternating current constantly reverses the magnetic forces between the voice coil and the permanent magnet, pushing the coil rapidly back and forth. When the coil moves, it pushes and pulls on the speaker cone. This causes the air in front of the speaker to vibrate, creating sound waves.
Children’s toys
In addition, magnetic discs can also be used in children’s toys, for example a ring magnetic disc is used in a magnet fishing game. The magnetic disc is attached to the end of the ‘fishing rod’ which is then hovered over the fish, which all have a piece of ferromagnetic material within them.When the magnetic disc is directly over the fish, the magnetic forces attract the two objects together, allowing the fish to be picked up.
