# 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 the electric current has a magnetic effect, while the magnet generates an electric current.

## The electromagnet

The electromagnet is a temporary magnet that 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.

Electromagnet

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 winches (cranes).

The electromagnet is used in making many appliances (devices) as the electric bell, the electric mixer, the disc drive, and the television.

#### How is 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.

### Electric effect of the magnet

In the 19th century, the English scientist 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.

### Electric generator (the dynamo)

A 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.

The electric current can be generated in a coil of dynamo by moving the coil in the magnetic field between the two poles of a magnet and by moving a magnet inside the coil.

The generation of the electric current in the coil increases by increasing the motion of the coil between the two poles of the magnet.

### Small dynamo

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.

### Huge dynamo

It consists of many great coils that turn between the two poles of a huge magnet, It converts kinetic (mechanical) energy into electric energy.

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 :

1. Wind electric power stations use wind energy to move the dynamo.
2. Thermal fuel electric power stations use the heat produced from burning fuel (oil, coal, and natural gas) to heat the water to produce steam which is used in moving the dynamo.
3. Nuclear electric power stations use nuclear reactors to produce the heat required for the movement of the dynamo.

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