02 Magnetism Flashcards
Two like poles
Repel
Two opposite poles
Attract
Magnetically soft materials
Easy to magnetise
Easy to lose magnetism (temporarily magnetised)
Magnetically hard materials
Difficult to magnetise
Don’t easily lose magnetism (permanently magnetised)
Permanent magnets are made out of
Magnetically hard materials
Example of magnetically soft material
Iron
Example of magnetically hard material
Steel
Electromagnetic are made out of
Magnetically soft materials
Magnetic field
A region around a magnetic where a force acts on another magnet or on a magnetic material
e.g. iron, steel, cobalt, nickel
Magnetic field lines
Used to represent the strength and direction of a magnetic field
If the magnetic field lines are close together
The magnetic field is strong
If the magnetic field lines are far apart
The magnetic field will be weak
Magnetic field is strongest
At the poles
The magnetic field becomes weaker
As the distance from the magnet increases
- shown by magnetic field lines getting further apart
Uniform fields
Created when two opposite poles are held close together
A uniform magnetic field has the same strength and direction at all points
- equal spacing
Induced magnetism
When a magnetic material is placed in a magnetic field, the material can temporarily be turned into a magnet
Investigate the magnetic field pattern for a permanent bar magnet between two bar magnets
- place magnet on piece on paper and draw dot on the corner
- place a plotting compass next to the dot so the needle points away
- draw dot where the compass faces
- move compass so it points away from new dot and repeat the process until there’s a chain of dots going from one end of the magnet from another
- remove compass and link the dots
- repeat to create other magnetic field lines
