Unit 8 Magnetism `

Magnetic Properties Permanent Magnets Permanent magnet Poles (north and south) If you chop them in half, each half still has a N and S pole Like poles repel Opposite poles attract Permanent magnet naturally magnetic materials iron, cobalt, and nickel

What makes materials magnetic? Groups of atoms that have aligned electrons are called domains domains are aligned in permanent magnets

Magnetic Field Every magnet creates a magnetic field in the space around it This is how magnets have forces between them without even touching

Electromagnets an electrical current passes through a coil of wire wrapped around some iron more current, stronger magnet Can be turned on and off

Electromagnetic induction Flowing current induces a magnetic field a moving magnet induces electrical current to flow

Electric Motor converts electrical energy into mechanical energy A current causes an electromagnet to rotate

Electric Generators Converts mechanical energy into electrical energy A coil of wire rotates within a magnetic field-generates a current Generator simulation

Making electricity Begin with fuel (chemical energy- fossil fuels) or another form of energy (nuclear, solar, hydro) Convert from one form of energy into mechanical energy (turn turbine- large fan) Turbine will rotate a magnet in a coil of copper wire (generator!!) Electrons flow in the wire…viola..electricity

Energy conversion

Transmitting electricity Increase voltage for travel Decrease voltage when at your home Use transformer – electrical device that changes voltage