Test over Magnetism- Friday

Agenda for the day

• Lecture- Magnetic Induction

• Finish Lab from yesterday… Making an electromagnet…turn in

Finish coloring magnetsphere…turn in

Question of the day

If you can make a magnet from electricity, can you also make electricity from a

magnet?

Michael Faraday• It was largely due to his

efforts that electricity became practical for use in technology. His efforts created the “ancestor” of the electric motor and generators.

• Discovered electromagnetic induction (1831) ….which was a turning point in physics

Electricity from Magnetism

Current is induced by changing the magnetic field

• Consider that there is no power source, but if you move the magnet or move the wire…current in created

REVIEW

• Which moves to create current? The wire or the magnet?

Does this mean we get something (energy) for nothing?

• The law of conservation of energy states that the Force times the distance traveled = Work done…

• Work input = work output (or energy stored)

What can you do to create more current?

Faraday’s Law

1)Increase the # of loops2)Make the magnet or wires move faster

“The Great Revolution”…Einstein

• http://www.youtube.com/watch?v=TEVEBzNSwTU

• And part 2