Electromagnets

• Force = magnetic field x current x length
• Permanent magnets

  • Produce their own magnetic field all the time
• Induced/temporary magnets

  • Only have magnetic field temporarily
• The strength of the magnetic field depends on the amount of current flowing through the wire, so if we increase the current then the magnetic field will get stronger.
• A magnetic field is made around a wire when a current flows.
• If the current is reversed, the direction of the magnetic field will change.
• A solenoid is a coil of wire that produces a magnetic field around it.
• Increasing the size of the current increases the strength of the magnetic field produced by a solenoid