Lesson 2 Summary - Making Magnets with an Electric Current


A magnetic field surrounds a moving electric charge.  Therefore, a complete circuit in which electricity is flowing also produces a magnetic field.

  • The closer you get to the wire, the stronger the magnetic field.

  • The more electric current flows through the wire, the stronger the magnetic field.


Magnets can also apply forces (attract and repel) to current carrying wires.  This is how electric motors are able to work.


An electromagnet is a temporary magnet turned on and off by electricity.

Electromagnets are created by taking a wire and wrapping it around a ferromagnetic core.  

Like permanent magnets, electromagnets have both a North and a South pole.

Electromagnets differ from permanent magnets in three important ways:

  1. Electromagnets can be turned on and off.  Permanent magnets always have their magnetic fields on.

  2. The strength of an electromagnet can be changed by adding more/taking away loops of wire around the core.  Also, you can change the strength by increasing the amount of current flowing through the wires.

  3. You can reverse the poles on an electromagnet, which you can’t do on a permanent magnet.


We use electromagnets in many devices, such as loudspeakers, power tools, electric fans, hair dryers, computers, and microwave ovens.


An electric motor is a device that uses an electric current to produce motion.  It converts electrical energy into mechanical energy, using magnetism.


  • A coil of wire that can turn is placed between the opposite poles of two permanent magnets.  

  • Electric current begins to flow through the coil.  The magnetic field created by the electric current is attracted to the magnetic field in the permanent magnets.

  • A device called a commutator reverses the direction of the current, and thus, the magnetic field created by the coil.  The like poles then repel each other and cause the coil of wire to spin.

  • The commutator continues to reverse the direction of the electric current and magnetic field whenever the magnetic poles line up, keeping the motor spinning