1. Remember?

2. Electromagnetic induction
Can you carefully wind your wire around the cardboard tube?

3. Electromagnetic induction
Put your coil in this circuit. The multimeter should be on the 200 mV scale. μA

4. Electromagnetic induction
MOVE a magnet in and out of the coil. Watch the meter! μA

5. Electromagnetic induction
If a magnet is moved inside a coil an electric current is induced (produced)
STICK IN please!

6. Electromagnetic induction
If a magnet is moved inside a coil an electric current is induced (produced)
STICK IN please!

7. Electromagnetic induction
An electric current is induced because the magnetic field around the coil is changing (the coil ‘cuts through’ the lines of field).
COPY this please!

8. Gather round

10. Can you stick this in please?
Generator/dynamo
A generator works by rotating a coil in a magnetic field (or rotating a magnet in a coil). A slip-ring commutator produces alternating current (a.c.)

11. Can you stick this in please?
Generator/dynamo
A generator works by rotating a coil in a magnetic field (or rotating a magnet in a coil). A slip-ring commutator produces alternating current (a.c.)

12. Stand up!

13. Alternating current
Current that goes backwards and forwards, changing direction 50 times a second (50 Hz)
COPY this please!

14. How to make more current?
Stronger magnet
More coils
Turn the coils faster

15. Bicycle dynamo