1. Magnetism from Electricity 8th Grade Science Weiner High School

2. The Discovery of Electromagnetism • In 1820, Danish physicist Hans Christian Oersted discovered a relationship between electricity and magnetism. • Oersted discovered when you hold a compass near an electric current it no longer points to the north. • Through experiments he also concluded that the compass changed direction depending on directional flow of the electrical current.

3. Using Electromagnetism • Electromagnetism is the interaction between electricity and magnetism. • The magnetic field created by an electric current in a wire may move a compass needle, but this alone is not very useful. • However when you add a solenoid to an electromagnet you strengthen the magneticfield. • Solenoid a coil of wire with an electric current in it.

4. Using Electromagnetism • A single loop of wire carrying a current does not have a very strong magnetic field, but suppose you form many loops into a coil. The magnetic fields of the individual loops will combine to form a stronger magnetic field. • The magnetic field around a solenoid is similar to that of a bar magnet. • If you add extra loops of wire and increase the flow of electricity you can increase the magnetic field.

5. Using Electromagnetism • Electromagnetsare made up of a solenoid wrapped around an iron core. • The magnetic field of the solenoid makes the domains inside the iron line up causing a magnetic field. • When you combine a solenoid with a magnet it is possible to make the magnetic field hundreds of times stronger. • You can make an electromagnet even stronger by adding more loops of wire to the solenoid. • One advantage to electromagnets is they can easily be turned on and off. • A solenoid only has a magnetic field when electricity is applied.

6. Electromagnet Usage • We use electromagnets everyday in things like doorbells, motors and many other things. • Doorbells: When you push the button of a doorbell you cause it to send an electric charge to a solenoid which creates a magnetic field that pushes a rod that sounds the bell. • Electric motor a device that converts electrical energy into mechanical energy.