P2.7 Magnetism Revision

4. The more ...., the larger the induced potential difference.
5. This transformer decreases the potential difference.
8. A stepup transformer has more turns on the ..... coil, to increase the induced (output) potential difference.
9. This transfomer increases the potential difference.
10. A .... magnet becomes magnetic when current flows through.
12. In an alternator, the faster the coil rotates the larger the ....
14. One of the transformers increases the potential difference, which makes the transmission of electricity more ...
15. A stepdown transformer has more turns on the ..... coil, to decrease the (output) induced potential difference.
19. In a dynamo, every 180 degrees the commutators .... to keep potential difference in one direction.
21. Loudspeakers use ... current, to produce a changing magnetic field.
23. A wire will experience a force, as the field around the wire and the external magnetic field ...
26. The ... coils of wire, the stronger the magnetic field.
27. A magnetic material: ....l.
28. To make a motor spin in the opposite direction, .... the magnets or the current.
29. Longitudinal waves have variations in .... (causing compressions and rarefactions).
30. The generator effect uses ... to induce a potential difference.

1. A wire will have a magnetic field, if there is ... flowing through.
2. When a potential difference is induced, if the circuit is .... current will flow.
3. A device that the potential difference remains in one direction, as the coil rotates in the magnetic field.
6. Magnetic field lines point away from ....
7. To make a motor rotate faster, use ... magnets.
8. Coiled wire.
11. The effect that a microphone uses.
13. A ... magnet does not lose magnetism when taken out of a magnetic field.
16. This is a word that describes a current carrying wire.
17. A transformer is made up of a: .... coil, secondary coil and iron core.
18. An iron core is used in a transformer as it is easily ....
20. A device that the potential difference changes direction as the coil rotates in a magnetic field.
22. This is the potential difference of mains electricity.
24. Opposite charges ...
25. The effect that a loudspeaker uses.