physics- magnetism and electromagnetism

• what do magnets do?

  attract or repel to other substances
• properties of hard magnetic materials

  • keeping its magnetism permanently
  • an example is steel
• properties of soft magnetic materials

  • loses its induced magnetism quickly
  • an example is iron
• what is a magnetic field line?

  A line that represents the size and direction of magnetic fields. They always point north to south.
• how is magnetism induced?

  • when magnetic materials are brought near to a magnet, that material acts as a magnet
  • this magnetism has been induced by the original magnet
  • the magnetic field from the magnet can make the electrons in the material move in the same direction
• how do you use two permanent magnets to produce a uniform magnetic field pattern

  by placing the north and south poles of two permanent bar magnets near each other
• how can magnetic field patterns be investigated? (practical)

  • compasses and iron fillings align themselves with magnetic fields
  • place the compasses around the bar magnet and trace the magnetic field lines coming out of it
  • or, put the magnet under a piece of paper, scatter the iron fillings on top, and tap the paper until the iron fillings form a clear pattern
• what is a magnetic field?

  a region where magnetic materials experience a force
• which materials are magnetic materials?

  iron, steel, cobalt, nickel