Electromagnetism

• When a Current flows through a Conducting Wire

  • A magnetic field is produced around the wire
  • The strength of the magnetic field depends on the Current through the wire and the Distance from the wire
  • When the current is reversed, the Direction of the magnetic field also reverses

  
• Solenoids

  • Shaping a wire to form a solenoid increases the Strength of the Magnetic Field created by a Current through the wire.
  • The Magnetic Field inside a solenoid is Strong and Uniform
  • The Magnetic Field around a solenoid has a similar shape to that of a Bar Magnet
  • An Electromagnet is a Solenoid with an iron core

  
• How does the Solenoid Arrangement increase the Magnetic Effect of the Current

  • The Small Magnetic Fields caused by the Current in each Coil add together to make a Stronger Overall Magnetic Field.
• How to increase the Strength of a Solenoid

  • Adding an iron core increases the strength of the magnetic field of a solenoid
  • Increasing the Current
  • Increasing the Number of Turns of Wire
  • Making the Wire Shorter, Keeping the same number of turns
• Electromagnets vs Permanent Magnets

  • Permanent Magnets have a fixed magnetic Strength, while Electromagnets can Magnetic Strength can be Changed
  • Electromagnets can be Turned ON and OFF, while Permanent Magnets Cannot