17.2 Electromagnets

Electromagnets Electromagnets: magnets that are created when there is electric current flowing in a wire

Building an Electromagnet You can easily build an electromagnet from wire and a piece of iron, such as a nail. Wrap the wire in many turns around the nail and connect a battery. Can you use materials other than iron?

Right-Hand Rule Curl the fingers of your right hand in the direction of the current in an electromagnet Your thumb will point towards the north pole

Permanent Magnets Charged electrons in atoms behave like small loops of current Atomic-scale electric currents create a permanent magnet when atoms align

Magnetic materials In magnetic materials, the atoms are free to rotate and easily align their individual north and south poles with a magnet. Hold up paperclip and ask what happens to the atoms – have students draw?

Nonmagnetic materials The atoms in non-magnetic materials, like plastic, are not free to move or change their magnetic orientation. Hold up ruler and bring it near magnet – ask what happens to the atoms