Generators, Motors and Transformers

The magnetic field lines around a wire are circles centred on the wire in a plane perpendicular to the wire.

Increasing current makes the magnetic field stronger.

Reversing the direction of the current reverses the magnetic field lines.

An electromagnet is made up of a coil of insulated wire wrapped around an iron core.

Subtopic

Magnets

Poles

There are two poles on a magnet north and south.

Like Poles repel each other.

Opposite Poles attract each other.

Magnetic Materials

Some metals can be magnetised to create elctromagnets

Normally Iron is used to create the core but you can use other materials such as nickel, steel and nickel.

Magnetic Fields

If iron filings are placed on a piece of paper around a magnetic you will be to see the magnetic field lines.

Also if you place compasses around the magnetic the arrows would point in the direction towards the south pole.

The further away a compass is away from the magnetic the less a affect it has on the compass direction as the magnetic field is weak.

In a uniform field the lines of a magnetic field are parallel to each other.