Lesson 2 Summary - Making Magnets with an Electric Current

Magnetic field

A region around a moving electric charge or a current-carrying wire where magnetic forces are experienced.

Electromagnet

A temporary magnet created by passing an electric current through a wire wrapped around a ferromagnetic core.

Electric motor

A device that converts electrical energy into mechanical energy using the principles of magnetism and electric current.

Commutator

A device in an electric motor that reverses the direction of the electric current in the coil, leading to a changing magnetic field and continuous rotation.

Electromagnet 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 changing the strength by adding/ taking away 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.

Like permanent magnets, electromagnets have both

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

A magnetic field surrounds a moving electric charge. 

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.

Electric Motors are able to work using

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