SP12-13

2. The difference in the energy carried by electrons before and after they have flowed through a component. Another term for potential difference.
4. A device attached to the rotating coil of a generator that makes electrical contact with an external circuit.
7. The area around a magnet where it can affect magnetic materials or induce a current.
9. The innermost part of something e.g. the central part of the Earth.
10. A machine for converting sound waves into changes in electrical current or voltage.
11. A thin sheet of flexible material.
15. A machine that produces electricity by rotating coils of wire in a magnetic field (or by rotating magnets near a coil of wire).
18. The force experienced by a wire carrying a current that is placed in a magnetic field.
22. A piece of material that becomes a magnet because it is in the magnetic field of another magnet.
23. The unit for magnetic flux density, also given as newtons per ampere metre (N/A m).
24. Current which changes direction many times each second.

1. A magnet made using a coil of wire with electricity flowing through it.
3. A small compass used to find the shape of a magnetic field.
5. A machine for converting changes in electrical current or voltage into sound waves.
6. A block of carbon that makes electrical contact between a circuit and a moving object such as a slip ring or commutator.
8. The difference in the energy carried by electrons before and after they have flowed through a component. Another term for voltage.
11. A generator that uses a commutator to change its output from alternating current to direct current.
12. A way of describing the strength of a magnetic field. It is measured in teslas (T).
13. A coil of wire with electricity flowing in it. Also called an electromagnet.
14. Current that always flows in the same direction.
16. A magnet that is always magnetic, such as a bar magnet.
17. A magnet that is not always magnetic, such as an electromagnet or an induced magnet.
19. Metal rings connected to the rotation coil in a generator. They make electrical contact with an external circuit.
20. A generator that produces alternating current.
21. To create. For example, a wire in a changing magnetic field has a current induced in it.