8.1 The Properties of Magnets Flashcards
List some magnetic materials
- Lodestone
- Iron
- Nickel
- Cobalt
- Stainless Steel
Anything which contains irons can attract magnets or be magnetised.
Do magnetic materials and magnets attract/repel?
- Magnetic materials do not attract or repel each other.
- Only two magnets will repel each other.
How do poles of a magnet work?
- There are 2 poles - North and South
- Monopoles don’t exist
- North and North, South and South will repel
- North and South will attract
List some magnetic materials which are popular for making permanent magnets and some popular for temporary.
Lodestone, Iron, Nickel and Cobalt are used for making permanent magnets whereas Stainless steel is good for temporary magnets.
What are domains?
Domains are small regions which a magnetic material is made up of.
How do domains affect magnetisation?
When a magnetic material is magnetised, all domains get aligned in the same direction. Domains in unmagnetised materials point in different directions.
What is magnetisation?
Magnetisation is the phenomena where an object made up of ferromagnetic material is converted temporarily into a magnet.
What are the ways for magnetisation?
- Electric Current
- Magnetic Field
- Extreme Temperature and Pressure Conditions
- Stroking the material with a magnet
How do we demagnetize an object?
You cannot turn a permanent magnet off. You can demagnetise it by:
- heating it up to a high temperature
- hitting it with a hammer.
How does Steel and Iron get magnetised?
Iron and steel are magnetised by being close to a magnet. Iron is easy to magnetize but loses magnetism when removed. Steel is harder but stays magnetised. A steel needle is slightly magnetised in a magnetic field. Stroking the needle repeatedly with a magnet creates a stronger magnet, making it a permanent magnet.
Why don’t all materials react to magnets?
- The material does not have enough domains.
- The domains are too strong to be aligned in the same direction.
