Electricity and Magnetism
There is close relationship between electricity and magnetism. You can cause electric current to flow in a coil of wire. This is when you cause a permanent magnet to move around (or towards) the wire or coil of wire. The energy of the magnet (magnetic energy) forces electrons in the wire to align in specific ways and produce electricity. The amount of electricity produced depends on the number of turns of wire, the strength of the magnet and how fast you moving the magnet or the coil. In fact, this is the basis of main electric power generators. The two ends of a magnet are North and South pole respectively.Basically, you can’t have so much electricity without magnetism. Electricity and magnetism are not exactly the same but there is a close relationship between them.
When you move a conductor in a magnetic field, you will produce electricity in that conductor. However, you need one of the two materials, (coil of wire or permanent magnet) to keep moving in order to produce the electricity. In fact, there must be a change in the magnetic field of force to produce electricity. Electricity produced depends on the number of turns of coil of wire and the rate of change of magnetic field.
Temporary magnet from electric field
You can make a temporary magnetic field (a temporary magnet) from electricity. When you pass a current through a piece of wire, you have a magnetic field around the conductor. The magnetic field is called ‘magnetic field of current’. You can increase the strength of the magnet by making the wire into a coil. Likewise, increasing the number of turns of the coil. On the other hand, you can increase the flow of current. This is the basis of all electromagnetic devices such as electric motor, relay, transformer, induction furnaces and solenoid. Using Fleming left hand rule, you can determine the north and south pole of the temporary magnet. Meanwhile, you can make current to flow in a wire from permanent magnet.
Induced Current from Magnetic Field
There is a direction to which induced current from magnetic field flows. The current will flow of in any of two ways clockwise or anticlockwise. The direction of flows depends on if the magnet move towards the coil of wire or moving away from it. If there is no movement relative to the magnet and coil of wire, there is no induced current.
Any change in the environment of a magnet and a coil of wire, will cause am EMF or voltage to be ‘induced’ in the coil. It does not matter how you produce the change. You may move the magnet towards or away from the coil. Or you move the coil towards or away from the magnet. You might as well rotate the magnet or the coil. As long there is a movement you induce current. You can confirm which direction current flows by using a galvanometer or an ammeter. Using Fleming right hand rule, you can determine the direction of flow of current.
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