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Copper in health
 What makes it turn? 
You can take a motor apart to see what it’s made of.

What's inside an electric motor?
Coil
The coil is made of copper wire - because it is such an excellent conductor (see conducting properties). It is wound onto an armature. The coil becomes an electromagnet when a current flows through it.
Armature
The armature supports the coil and can help make the electromagnet stronger. This makes the motor more efficient.
Permanent magnets
There are two permanent magnets. They produce a steady magentic field so that the coil will turn when a current flows in it.
Some motors have electromagnets instead of permanent magnets. These are made from more coils of copper wire.
Commutator
Each end of the coil is connected to one of the two halves of the commutator. The commutator swaps the contacts over every half turn.
Brushes
The brushes press on the commutator. They keep contact with the commutator even though it is spinning round. The current flows in and out of the motor through the brushes.
Steel former
The former made of magnetic material links the two permanent magnets and, in effect, makes them into a single horseshoe shaped magnet. Commercial motors often use a horseshoe magnet.

Interactive graphic of motor Interactive graphic of motor Interactive graphic of motor
Interactive graphic of motor
Picture 2. A simple electric motor. Use the highlighted words in the text to find out how it works.
How does it work?
The motor is connected to a battery. When the switch is closed, the current starts to flow and the coil becomes an electromagnet. In this case the current is flowing anticlockwise in the top of the coil. This makes the top a north pole. This north pole is attracted to the south pole on the left. So the top of the coil turns towards the left. Notice that the bottom of the coil is a south pole and is attracted to the magnet on the right.

Once the coil gets to the upright position, there is no turning force on it because the electromagnet of the coil is lined up with the permanent magnets. If the current in the coil were constant, the coil would stop in this position. However, to keep it spinning, the commutator breaks contact in this position. So the current stops for an instant. The momentum of the coil keeps it going and the contacts are reconnected. However, they are now the other way around. So, the side of the coil that used to be a south pole is now a north pole.

The commutator will keep swapping the contacts every half turn (when the coil is in the upright position). In this way, the motor keeps spinning.

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Question 1
Look at the descriptions below. Each one describes a part of an electric motor. In each case, type in the name of the part. Choose from the list at the bottom.

Use only small letters and make sure you spell the names correctly.

Provides a steady magnetic field.
Automatically reverses the current in the coil.
Becomes an electromagnet when a current flows.
Feeds the current into or out of the motor.
Supports the coil and can strengthen the magnetic field.

commutator, brushes, coil, armature, magnets.