Properties of Magnets
When 2 bar magnets are joined together → the overall strength of the combined magnet:
- stronger than that of 1 bar magnet
- is weaker than the sum of the strength of both magnets
→ this is because when 2 magnets are stuck together → the overall magnetic field is the vector sum of the magnetic field of each magnet → however edges of magnets that are in contact with each other are now one magnet away from the edge of the other magnet. → thus field strength is weaker than sum of field strength of both magnets.
Induced Magnetism
Demagnetisation
Temporary and Permanent Magnets
Temporary and Permanent Magnets
Showing Magnetic Field Around Magnet
Showing Magnetic Field Around Magnet
Sample
when ATQ → state proximity of object to pole of magnet.
Definition
Compass needle is a tiny bar magnet suspended on a pivot to move freely in a horizontal plane
Note
uses of compass needle
- lost travellers
- plot field lines in a magnetic field pattern
Important
if object is moving freely in presence of magnetic field, it will move along the magnetic field lines. e.g. of needle in water (WB) → moved in curved pathway along magnetic field lines