Making the Connection

► All matter is made up of extremely small particles called ATOMS which are constantly in motion.

► Beyond the nucleus of atoms are ELECTRONS which are negatively charged.

► Electricity is produced when there is a flow of CHARGE. ► Magnetic fields are produced by the motion of electric CHARGE.

► Atoms of iron have moving electrons in them which produce the moving electric CHARGE causing a mini-magnetic field around the atom. ► If enough of these atoms become aligned with each other, a magnetic DOMAIN is created and thus a magnet.

► Electricity and magnetism were regarded as unrelated PHENOMENA until the nineteenth century.

► This changed in 1820 when a Danish science professor, Hans Christian Oersted, discovered a relationship between the two when demonstrating electric currents in front of a class of students.

► When electric current was passed in a wire near a magnetic COMPASS, both Oersted and his students noticed the deflection of the COMPASS needle.

► A few years later, in England, Michael Faraday demonstrated the reverse---a magnetic field produces electricity. ► Faraday’s discovery led to the invention of the first electrical GENERATOR, the magnetic dynamo.

► Once magnets were found to exert FORCES on current-carrying wires, this paved the way for discoveries such as electric MOTORS and power, telegraphs, radio, television, stereos, ETC!

► Faraday is considered by many as the “father” of electricity!

Faraday’s Finest pg 14 ► Electrical generators are devices which rotate a coil of wire in a magnetic field to produce ELECTRICITY.

► There are may ways the ROTOR of a generator can be made to turn.

► Electrical motors are very similar to generators, except electricity is used to make MAGNETIC fields which causes the rotor of the motor to turn.

► A= magnet ► B= coil ► C= rotor ► D= wires

► A MOTOR converts electrical energy to mechanical energy. ► A GENERATOR converts mechanical energy to electrical energy.

► What are the major components of motors and generators?  Rotating coil or loop  magnet ► What are the major components of speakers? A speaker is really just a motor

Back to Page 6 ► James Clark Maxwell realized electricity and magnetism are different manifestations of the same phenomena called ELECTROMAGNETISM.

► Maxwell produced a set of four equations which govern every aspect of electric and magnetic PHENOMENA. ► Perhaps one of the most astonishing ramifications of Maxwell’s work was that light was an ELECTROMAGNETIC wave.

► Albert Einstein then theorized light may be taken to be made up of vast amounts of packets of EM radiation.