Overview
This lecture introduces the basics of magnets, how they work, different types, their properties, and real-world uses.
What Are Magnets?
- A magnet is an object that attracts specific metals like iron and steel.
- Magnets have an invisible area around them called a magnetic field that pulls certain metals toward them.
Types of Magnets
- Permanent magnets always attract metal objects and are found in items like fridge doors and toys.
- Temporary magnets only act like magnets when near a strong magnet (e.g., a paperclip near a magnet).
- Electromagnets work when electricity flows through them and are used in junkyards, doorbells, and roller coasters.
Magnet Poles
- Every magnet has two ends: a North pole and a South pole.
- Opposite poles attract, while like poles repel each other.
Magnetic Fields
- The magnetic field is the invisible bubble around a magnet where its force works.
- Iron filings around a magnet show the magnetic field's pattern.
What Magnets Attract
- Magnets attract metals like iron, steel, paper clips, and nails.
- They do not attract materials like plastic, glass, wood, or cloth.
Uses of Magnets
- Magnets are used in computers to store data, in earbuds to produce sound, and in electric cars for smooth operation.
- MRI machines use strong magnets to help doctors see inside the body.
- Maglev trains use powerful magnets to float above tracks.
- Compasses rely on Earth’s magnetic field to show direction.
Key Terms & Definitions
- Magnet — An object that attracts certain metals like iron and steel.
- Magnetic Field — The invisible area around a magnet where its force is felt.
- Permanent Magnet — Always magnetic, used in everyday items.
- Temporary Magnet — Becomes magnetic only near another magnet.
- Electromagnet — Becomes magnetic when electricity flows through it.
- Pole — The North or South end of a magnet where its power is strongest.
Action Items / Next Steps
- Review the different types of magnets and their uses.
- Observe which household materials are attracted to a magnet.
- Prepare for a quick quiz on magnet basics.