Science Unit - Magnetic Fields

• Magnet Rule


  Like poles repel, opposite poles attract
• Like poles

  • North and north
  • South and south
• Opposite poles


  • North and south
• Permanent Magnets


  • All the electrons are aligned
• Temporary Magnets


  • The electrons become aligned if it's rubbed by a magnetic material
• The Earth's crust has some permanent magnetisation, and the Earth's core generates its magnetic field, sustaining the main part of the field we measure at the surface
• The compass needle points to a position near the Earth's actual geographic north pole


  It points to a point called the magnetic north
• The magnetic north is the magnetic south pole
• Electromagnet


  A magnetic field created by electric currents
• Factors affecting electromagnet strength

  • The strength can be adjusted
  • The power of voltage of battery/quantity of batteries
  • The size of the core
  • Number of turns in coils around the core
  • Material used for the core
• How electromagnets work


  When the batteries are turned on or connected, current passes through the coil magnetising the core
• Magnetic Materials

  • Iron
  • Nickel
  • Cobalt