Background ResearchWhat is magnetism and how does it work? Greeks discovered magnetite hundreds of years ago. The name that the Greeks came up with came from the place where they found these rocks, which was Magnesia in Asia Minor, which is also called Turkey today. Some molecules are electrically charged, and good conductors of magnetic force. When the molecules are lined up in the same direction inside a conductive object (like an iron bar) the object becomes a magnet. Magnetic molecules have a positive charge and a negative charge end. On a magnet, their like charges (for example, positive and positive, or negative and negative) repel from each other, but the opposite or unlike charge (positive and negative) attract each (Gonick & Huffman).
What is the difference between a permanent magnet and an electromagnet? An electromagnet can be turned on and off while a permanent magnet is always “on.” Electromagnets can be made to variable strengths, while a permanent magnet’s strength is fixed. Electromagnets are also improved solenoids because you put an iron core in the center of the solenoid which focuses the magnetic field generated by the coil. Electromagnets are used for picking up ferrous objects. They are also used for electrical and electronic equipment purposes, such as a door bell or a stereo speaker (Gerrish, Gugger, Jr. & DeLucca).
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What are some ways that magnetic fields effect our everyday lives? The Earth’s core is a giant magnet that creates a huge geomagnetic field surrounding our planet. The geomagnetic field reaches into space thousands of kilometers. This magnetic field protects us from charged subatomic particles and solar radiation. The field is also what makes a compass work. Radio and television signals, as well as the flow of electricity are also dependent on magnetic fields to work (Gibilisco).
Another example is a recording device, such as a hard drive in a computer. In a hard drive, small pieces of magnetic metal are imbeded in a disk in a specific pattern to allow information to be saved. The data is then stored in s special computer language only using 1’s and 0’s (a 1 is a magnetized particle, a 0 is an un-magnetized particle). When retrieved, it is sorted into the normal human language again. The current going through the computer’s circuits energizes small electromagnets which magnetize the small pieces of metal in the disk (Brain & Looper). What makes ferrofluid react to electromagnets? Ferrofluids were discovered in the 1960s at The NASA Research Center where scientists were looking for different ways of controlling liquids in space. Ferrofluid consists of nano particles of iron or other ferromagnetic material suspended in liquid. Magnnets exert an attractive force on the nano particles causing them to align with the lines of magnetism. Nano particles are particles less than 10nm in size. The liquid keeps the nano particles spaced out a little so they don't just clump together (University of Wisconsin-Madison).
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