Magnetism & Electromagnetism Magnetic forces arise from the movement of electrical charge. Electromagnetism is the interaction between electricity and magnetism. A magnet can exert a force on a wire carrying a current. A current creates a magnetic force field Generators and motors use electromagnetism.

Magnets and Magnetic Fields Magnets can be classified as ferromagnets, electromagnets, temporary magnets, and permanent magnets. A material is magnetic if its domains line up Magnetic materials include iron, nickel, and cobalt Every magnet is surrounded by a magnetic field. The shape of the field can be shown with magnetic field lines.

Domains – regions of aligned electron spins

Electromagnetism Magnets can induce electric current and be used to produce electricity in generators Generators convert mechanical energy to electrical energy. Electric current can produce a magnetic field and be used to create an electromagnet Electromagnets are used in electric motors to transform electrical energy to mechanical energy.

Electromagnetism Moving a magnet through a coil of wires generates electric current

Basic Generator A moving magnet called the ROTOR moves through a stationary coil of wires called the STATOR. The moving magnet’s field generates a flow of electrons, creating a current.

Basic Motor Electricity flowing through a coil of wire generates a magnetic field. This field interacts with the permanent magnet’s poles This interaction cause the coil to spin.

This coil of wire is called a SOLENOID Electromagnetism Flowing electricity creates a magnetic force field This coil of wire is called a SOLENOID

Electromagnetism Add an iron core and you create an electromagnet as the electricity causes the iron’s domains to align

Advantages of Electromagnets Can be turned off and on Can be made stronger (by more coils, larger core, or more current) Polarity can be reversed

World’s Simplest Motor! Let’s try it! Your table will get: 1 D-cell battery (source of electricity) 1 neodymium magnet (very strong) 1 finishing screw (made of coated steel - ferromagnetic) 1 piece of copper wire (good conductor)