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Making a permanent Magnet:
Ever thought of making your own permanent Magnet from the scrap available.Here is the way to do it.
- Gather the piece of iron you want to make as a permanent Magnet
- Now wind the insulated copper wire round the piece of metal a large no.of turns i.e. about 150-200 turns is needed.Leave the two ends of the wire for connection to a power supply.
- Connect the two ends of the copper wire to the DC power supply and leave it for few minutes
- Test the iron piece if it is magnetised by using some small nails,paper clips etc.
What is happening?
An iron piece gets magnetised by applying constant magnetic field in the same direction i.e. an iron piece can be magnetised by placing it in a magnetic field.Now when the two terminals of the insulated copper winding are connected to the DC Power Supply due to the low resistance in the copper wire a high current flows then a constant magnetic field is produced in one direction along the length of the iron piece. This constant magnetic field magnetises the iron piece.At molecular level electrons get aligned at one end and this responsible for the magnetism shown by the piece of magnet.Thus the rate of magnetisation of the iron piece depends upon the electron movement.The mobility of the electrons can be increased by heating the iron piece to red hot.At this temperature the electrons are freed from the molecular forces and hence gets easily aligned in the direction of magnetic field.
An iron piece gets magnetised by applying constant magnetic field in the same direction i.e. an iron piece can be magnetised by placing it in a magnetic field.Now when the two terminals of the insulated copper winding are connected to the DC Power Supply due to the low resistance in the copper wire a high current flows then a constant magnetic field is produced in one direction along the length of the iron piece. This constant magnetic field magnetises the iron piece.At molecular level electrons get aligned at one end and this responsible for the magnetism shown by the piece of magnet.Thus the rate of magnetisation of the iron piece depends upon the electron movement.The mobility of the electrons can be increased by heating the iron piece to red hot.At this temperature the electrons are freed from the molecular forces and hence gets easily aligned in the direction of magnetic field.
Want a more powerful magnet?
- Determine which way north is using the
compass. When creating a powerful permanent magne,t it is necessary to
take the earth's magnetic field into account so that it works with the
magnetizing and not against it. If the magnetic field of the earth is
not lined up with the magnetic field induced in the metal, then they
will fight with and weaken each other. Though the earth's magnetic field
is weak, if you want the best results, you must take it into account..
- Start the grill, getting it as hot as possible. Place the iron bar on the grill so that it lines up along the north-south line. Iron is used because it has the highest relative permeability. Relative permeability is a measurement of how susceptible the material is to magnetic fields. Iron is one of the most susceptible materials. Get the iron hot enough to start glowing red. Use the propane torch to help the heating process.
- Holding the iron in the tongs, remove it from the heat. Wearing the gloves to protect your hands, stroke the iron with the magnet. Only stroke it in one direction; do not move the magnet back and forth. Keep the iron bar along the north-south line.
- Let the iron cool. Once it has cooled to room temperature, it will be a powerful permanent magnet.