Unit Seven Summary

Unit Seven Unit Summary – Magnetism

What did we learn the unit?

Forces on charged particles in an electric field; Motors

            A motor must have two components, a magnet and current carrying wire. The current in the wire when perpendicular to the magnet induces a torque, causing the current carrying wire to spin. A magnet’s magnetic field flows from north to south, and is why the north pole of the earth is actually magnetically south. In order for a magnet to form the domains must align in a single direction. A domain is a group of electrons which move together.

Electromagnetic induction common applications

            Electromagnetic induction is present in everyday life, in stoplight turn signals, credit card machines, and metal detectors. All work by shifting a magnet in a coil of wire to cause a voltage, which creates a current. This then sends a message in the form of a current to either the switch box in the stop light, the card reader in the card machine, or the beeper in a metal detector.

Generators and Energy Production

            Generators work by spinning magnets around coils of wire, which creates a voltage by electromagnetic induction. To get the magnets to spin often water is boiled creating steam, which turns the fan blades attached to the magnets. This is creates alternating Current.

Transformers and Energy transfer from Power Company to Home

A transformer works by utilizing faraday’s Law, by using electromagnetic induction to increase voltage or to lower the voltage. There are two types of transformers, Step up which increase voltage, and step down which reduce voltage. Transformers rely on alternating current to be able to induct voltages.

Formulas

Faraday’s law

Number of loops of wire / voltage of primary = Number of loops of wire / voltage of secondary

How does this relate to the real world?

     Magnets, electromagnetic induction, and motors are the grounds, on which our society is built. They provide the power to keep the lights on, create the machinery that provides convenience, and builds the motors to power our fans in our dorms. Without magnetism the world still be in the stone age.