# GCSE PHYSICS UNIT 3

Some notes on P3 that will hopefully help.

Look at my other resources for more help

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• Created by: Diamanti
• Created on: 26-05-11 15:35

## Electromagnetic Induction

When a wire is moved through a magnetic field.

Potential difference is induced at the ends of the wires.

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## Electromagnetic Induction

You can increase the voltage output by:

• Increasing the area of the coils
• Increasing the number of coils
• Increasing the magnets strength
• Increase the speed of movement
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## Electromagnetic Induction

If you use a stronger magnet:

• The wire kicks forward

If the magnet is reversed:

• The wire moves the other way
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## Motor Effect

When a current is passed along a wire in a magnetic field, it may experience a force. This force, believe it or not, is called the Motor Effect. Fun, no?

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## Motor Effect

The size of the force can be increased by:

• Increasing the strength of magnetic field
• Increasing the size of the current

The direction of the force on the wire can be reversed if either the magnetic field or current are REVERSED or DESREVER

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## Transformer

Direct current does not induce ALTERNATING MAGNETIC FIELDS so a seconday voltage won't be produced.

AC is used in transformers

ALTERNATING CURRENT is used

AC  CURRENT !!!!

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