Magnetism from Electricity Did you know? Most trains you see roll on wheels on top of a track. But engineers have developed trains with no wheels that FLOAT above the track! These trains are able to levitate because of magnetic forces between the track and the train cars. Most trains you see roll on wheels on top of a track. But engineers have developed trains with no wheels that FLOAT above the track! These trains are able to levitate because of magnetic forces between the track and the train cars.

Magnetism from Electricity Danish physicist Hans Christian Oersted discovered the relationship between electricity and magnetism in 1820.Danish physicist Hans Christian Oersted discovered the relationship between electricity and magnetism in 1820.

Magnetism from Electricity A magnetic needleA magnetic needle balances on the balances on the central rod. The two central rod. The two end posts support a end posts support a metal wire. Each end metal wire. Each end of the wire extends down of the wire extends down through the wooden posts and is connected to a small metal post in the base. When one metal post was connected to the positive pole of a battery and the other metal post was connected to the negative pole of a battery, current would flow in the wire. The needle would then swing until it was at right angles to the wire. through the wooden posts and is connected to a small metal post in the base. When one metal post was connected to the positive pole of a battery and the other metal post was connected to the negative pole of a battery, current would flow in the wire. The needle would then swing until it was at right angles to the wire.

Magnetism from Electricity French scientist Andre-Marie Ampere heard about Oersted’s findings and did more research. Together their work was the first research conducted on electromagnetism.French scientist Andre-Marie Ampere heard about Oersted’s findings and did more research. Together their work was the first research conducted on electromagnetism. Electromagnetism is the interaction between electricity and magnetism.Electromagnetism is the interaction between electricity and magnetism.

Magnetism from Electricity Although the magnetic field created by an electric current in a wire may deflect a compass needle, it is not strong enough to be very useful.Although the magnetic field created by an electric current in a wire may deflect a compass needle, it is not strong enough to be very useful. Two devices, the solenoid and the electromagnet, strengthen the magnetic field enough to be useful.Two devices, the solenoid and the electromagnet, strengthen the magnetic field enough to be useful.

Magnetism from Electricity A solenoid is a coil of wire that produces a magnetic field when carrying an electric current.A solenoid is a coil of wire that produces a magnetic field when carrying an electric current.

Magnetism from Electricity The strength of the magnetic field increases as more loops of wire are added and as the current in the wire is increased.The strength of the magnetic field increases as more loops of wire are added and as the current in the wire is increased.

Magnetism from Electricity An electromagnet is a magnet that consists of a solenoid wrapped around an iron core. The magnetic field produced by the solenoid causes the domains in the iron to become better aligned.An electromagnet is a magnet that consists of a solenoid wrapped around an iron core. The magnetic field produced by the solenoid causes the domains in the iron to become better aligned.

Magnetism from Electricity An electric motor is a device that changes electrical energy into kinetic energy.An electric motor is a device that changes electrical energy into kinetic energy. All electric motors have an armature, a loop or coil of wire that can rotate. The armature is mounted between the poles of a magnet.All electric motors have an armature, a loop or coil of wire that can rotate. The armature is mounted between the poles of a magnet.

Magnetism from Electricity A simple DC electric motor. When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn toward the right, causing rotation.A simple DC electric motor. When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn toward the right, causing rotation.

Magnetism from Electricity The armature continues to rotateThe armature continues to rotate

Magnetism from Electricity When the armature becomes horizontally aligned, the commutator reverses the direction of current through the coil, reversing the magnetic field. The process then repeats.When the armature becomes horizontally aligned, the commutator reverses the direction of current through the coil, reversing the magnetic field. The process then repeats.

Magnetism from Electricity A galvanometer is a device used to measure current through the interaction of an electromagnet and a permanent magnet.A galvanometer is a device used to measure current through the interaction of an electromagnet and a permanent magnet.