Magnetism

• What type of materials do magnets attracts?

  magnetic materials.
• What are the four magnetic materials?

  iron, cobalt, nickel and steel
• What are the strongest parts of a magnet called?

  the poles
• What are the two types of magnetic materials?

  • magnetically soft materials
  • magnetically hard materials
• What are magnetically soft materials?

  magnetic materials that lose their magnetism once the magnet is removed. they are used to make temporary magnets.
• What are magnetically hard materials?

  They are magnetic material that keep their magnetism once they have been magnetised. They are used to make permanent magnets.
• What are magnetic fields?

  They are lines that represent the magnetic force of a magnet.
• What do magnetic field lines show ?

  • shape of the magnetic field
  • direction of the magnetic force
  • strength of the magnetic field
• How can we detect a magnetic field?

  • place multiple plotting compasses around the bar magnet
  • plot points according to the direction of the compass needles
• How can we create a uniform magnetic field?

  By placing the north pole of one bar magnet near the south pole of another bar magnet.
• What is a uniform magnetic field?


  A magnetic field that's strength and direction is the same everywhere.
• What is induced magnetism?

  When a magnetic material is placed inside a magnetic field and it becomes magnetised.
• What is electromagnetism?

  When there is a current in a wire a magnetic field is produced around the wire. This is called electromagnetism.
• How can the strength of the magnetic field around a current carrying wire be increased?

  • increasing current in the wire
  • wrapping the wire into a coil
• How can the strength of the magnetic field around a solenoid be increased?

  • increasing current in the solenoid
  • increasing the number of turns on the solenoid
  • wrapping the solenoid around a magnetically soft core
• Explain how an electric motor works.

  • Current flows through the coil
  • Current produces a magnetic field around the coil
  • Magnetic field of the coil interacts with the magnetic field of the permanent magnet
  • This exerts a force on the coil
  • direction of current reverses every half turn
• How can we predict the direction of force exerted on a wire?

  Flemings left hand rule