Electromagnet , Electric generator ( Dynamo ) uses , structure and types
The electric current can be used to generate a magnetic effect ( magnetic field ) or magnetism can be generated by electricity , There is a relation between magnetism and electricity , where electric current has a magnetic effect , while magnet generates an electric current .
It is a temporary magnet which is made by the effect of electricity , It consists of a bar wrought ( soft ) iron , A twisted copper wire coiling around the bar of iron and a dry cell ( battery ) , When the electric current passes through the wire , the bar of the wrought iron works as a magnet .
When an electric current passes through a coil winding around a wrought ( soft ) iron bar , the iron bar becomes a temporary magnet that is called the electromagnet .
The magnetic force of the electromagnetic can be increased by increasing the number of coil turns , and by increasing the number of batteries , where the intensity of the electric current passing through the coil increases .
Wrought iron is used for making the electromagnet because the wrought iron gains and loses the magnetism easily , The magnetic force of the electromagnet increases by increasing the number of batteries because the intensity of the electric current passing through the coil increases .
Uses of the electromagnet
The electromagnet is used in factories to move ( lift ) the heavy iron blocks as it is used for making big-sized winch ( crane ) .
The electromagnet is used in making many appliances ( devices ) as the electric bell , the electric mixer , the disc drive and the television .
How the electromagnet used for moving up the heavy iron blocks ?
The huge electromagnet is hung in a big-sized winch , The winch depresses the electromagnet over iron or steel blocks ( or scrap cars ) to lift them , so , by passing the electric current through the coil of the electromagnet , it will attract the iron blocks and move them to another place , By cutting the electric current , the electromagnet loses its magnetic force and iron or steel blocks fall .
The electric effect of the magnet
In the 19th century , the English scientists Faraday discovered that when a magnet is moved inside a coil of wire , an electric current passes through the coil , so , the lamp lights , this means that the electric energy ( electric current ) can be generated by using a magnet , Faraday used this discovery to make an electric generator known as the dynamo .
The electric generator ( the dynamo )
Dynamo is made up of a copper coil and a magnet , It converts mechanical ( kinetic ) energy into electric energy , where the kinetic energy moves the copper coil between the two poles of the magnet to produce the electricity .
It consists of a small cylinder that touches the bicycle wheel tire , this cylinder is connected to a U-shaped ( horse-shoe ) magnet that is surrounded by a coil , It generates a small amount of electricity used to lighten the bicycle’s bulb .
It converts kinetic ( mechanical ) energy into electric energy , as when the bicycle moves the small cylinder turns because it touches the bicycle wheel tire , so , the magnet turns inside the coil causing the lightening of the bicycle’s bulb .
It is used in the electric power stations to generate a large amount of electricity used for lightening cities and operating factories .
The produced amount of electricity from the dynamo can be increased by using a strong magnet , and by increasing the number of turns in the moving coils .
There are three types of electric power stations which are :
- Wind electric power stations use wind energy to move the dynamo .
- Thermal fuel electric power stations use the heat produced from burning fuel ( oil , coal and natural gas ) for heating the water to produce steam which is used in moving the dynamo .
- Nuclear electric power stations use the nuclear reactors to produce the heat required for the movement of the dynamo .