Magnetism & Electromagnetism

• North -> south
• magnetic field is stronger the closer it is to the magnet
• magnetic material:

  Nickel

  Cobalt

  Iron

  Steel

  NCIS
• Permanent magnets - A magnet that always has a magnetic field
• Magnetically soft - loses magnetism very quickly eg Nickel , Iron
• Magnetically hard - harder to lose magnetism eg steel
• Electromagnetism - Using current to product magnetic field
• Field lines always perpendicular to current
• Solenoid - A coil of wire that produces a magnetic field when current is passed through it. Inside is strong and uniform
• ways to increase electromagnet strength:

  Increase current

  Increase number of turns

  Decrease distance between each loop

  Iron core