What is Magnetism? Ferromagnetic materials such as Iron and Nickel have a strong attraction to magnets. The magnetic field around a current-carrying wire is made of closed circles. All magnets have certain similarities: North and South Poles. Curved lines of showing their magnetic field. Opposites attract; north attracts south.

Magnetic Materials A magnet will attract or repel another magnet. Again, opposites attract. A magnet will attract a magnetic material, such as an iron nail, but not repel it, as the magnetic material is not a magnet. If a material is nonmagnetic, such as wood or glass or granite, it will not be attracted or repelled by a magnet.

Types of magnets A temporary magnet loses it magnetism when it is removed from a magnetic field. A permanent magnets stays magnetic even when removed from another magnetic field. An electromagnet is made by wrapping electric current carrying wire around a magnetic core (iron, etc.). Both permanent magnets and electromagnets are used in electric motors.

Electric Motors In an electric motor, poles of an electromagnet and a permanent magnet alternatively attract and repel each other. The current then reverses itself. This keeps the motor moving (spinning around) turning electric energy into mechanical energy.

Using Magnets If you move a magnet inside a wire coil, it will make an electric current. You can also move a wire coil around a magnet to make an electric current. ELECTROmagnets are different from permanent magnets because… They can be turned on and off. Their strength can be controlled by the amount of current in the wire. The poles can be reversed (north to south and south to north).

Electromagnets

Electric Power Plants In a power plant, turbines produce mechanical energy. This energy is transferred to a generator in the power plant. The generator transforms the mechanical energy from the turbine into electrical energy. The electrical energy then goes to a step- up transformed that increases the voltage for moving the current a long distance over power lines. Then a step-down transformer reduces voltage for local powerlines, and another one reduces it even more before the current goes safely into a house.

Power plant