Magnetism and Electromagnetism

• Where are the magnetic forces the strongest on a magnet?

  at the poles
• What happens when you place like poles of a magnet next to each other?

  they repel
• What happens when you place unlike poles on a magnet next to each other?

  they attract
• Which materials are magnetic?

  • Nickel
  • Cobalt
  • Iron
  • Steel
• What is the direction of the magnetic field?

  From North to South
• How do you change strength of an electromagnet?

  • increasing the number of coils
  • inserting an iron core
  • increasing the current
• What is the difference between a permanent and induced magnet?

  A permanent magnet produces its own magnetic field. An induced magnet is a material that becomes a magnet when it is placed in a magnetic field.
• what happens to the strength of a magnetic field the further away you are from the magnet

  it becomes weaker
• What happens when a current flows through a conducting wire?

  a magnetic field is produced around the wire
• What affects the strength of the magnetic field around a wire?

  the current through the wire and the distance from the wire
• what does shaping a wire to form a solenoid do to the magnetic field?

  increases the strength of the magnetic field created by a current through the wire
• What is an electromagnet?

  a solenoid with an iron core
• What is the motor effect?

  "When a conductor carrying a current is placed in a magnetic field the magnet producing the field and the conductor exert a force on each other."
• What are the units for force?

  N or newtons
• What are the units for magnetic flux density?

  T or tesla
• What are the units for current?

  A or Amps
• What are the units for length?

  m or metres
• What do you call a coil of wire carrying a current in a magnetic field that has a tendency to rotate?

  An electric motor
• What is the direction of the force?

  A

  
• What is the direction of Field?

  B

  
• What is the direction of the current?

  C