Summary
Electricity and magnetism involve the study of magnets, magnetic fields, and electromagnets. Magnets have properties that allow them to attract certain materials, and electromagnets can be controlled by electricity.
- Magnetism — a force that attracts certain metals. Example: Lodestone attracts iron.
- Bar Magnet — a permanent magnet with constant magnetism. Example: Bar magnets have north and south poles.
- Magnetic Field — the area around a magnet where magnetic forces act. Example: Field lines show the direction of magnetic forces.
- Electromagnet — a magnet created by electricity. Example: A coil with current acts like a magnet.
- Permanent Magnet — a magnet that retains its magnetism. Example: Made from iron, nickel, or cobalt.
- Induced Magnetism — temporary magnetism in a material. Example: Iron becomes magnetic near a magnet.
Exam Tips
Key Definitions to Remember
- Magnetism: A force that attracts certain metals.
- Bar Magnet: A permanent magnet with north and south poles.
- Magnetic Field: The area around a magnet where forces act.
- Electromagnet: A magnet created by an electric current.
Common Confusions
- Confusing permanent magnets with electromagnets.
- Thinking magnetic field lines can be seen.
Typical Exam Questions
- What word best describes bar magnets? Permanent
- What do opposite poles do? Attract
- Specifically in which direction do the lines run in a field diagram? North to south
What Examiners Usually Test
- Understanding of magnetic field diagrams.
- Differences between permanent magnets and electromagnets.
- Applications of electromagnets in real life.