# Magnetic induction

• Any change in the magnetic flux passing through a loop of wire will cause an EMF to be induced in the loop
• The EMF produces a current
• The current in the loop has its own magnetic field
• The induced magnetic field opposes any changes to flux, but cannot oppose the change fully

### Lenz’s law

If the magnetic flux through a loop changes,

• A current will be induced in the loop
• The current produces a magnetic flux that opposes the original change

Very similar to inertia

• If the flux increases, the loop will produce a flux that tries to decrease the flux.
• If the flux decreases, the loop produces a flux that tries to increase the flux
• If the north pole of a magnet is moved towards the loop, it will produce a north pole to oppose the magnet
• If the north pole is moved away from the loop, it will produceĀ  south pole to oppose the magnet’s motion
• Similar principles apply for a south pole

### Electromagnetic induction

• The induced current is directly proportional to the rate of change of flux
• The faster the rate of change, the greater the current
• The creation of an electric current due to changes in a magnetic field is called electromagnetic induction
• The conductor carrying the induced current is called an inductor