Magnetism

Electromagnetic Induction

            This is the process by which a magnet passes over or through loops of wires and induces a voltage. This in turn creates current in the wire that can be used to send signals or to produce electricity. This process is used for traffic lights, credit cards, and transformers. Traffic lights have loops of wires in the ground so that when a car drives over them they induce a voltage creating a current that signals the traffic light to change colors. The credit card has a series of magnets on the back of it, the credit card machine has loops in it so that when the magnets on the back of the card pass through the loops inducing voltage in the wires that creates a very specific current that is identified only as that specific credit card. The transformer has loops of wires in it, one has more loops than the other and the transformer is able to convert the current to either AC or DC current. This process is also used to generate electricity, there are loops of wires and rotating magnets around them, the only requirement is the mechanical needed to rotate the magnets and generate electric energy.

Moving Charges

            Moving charges are the source of all magnetism. Moving charge determine the direction of the domains in the magnetized objects. Domains are the direction that the charge is spinning, when they are all in the same direction they are a fully magnetized. The more domains face the same direction the more powerful the magnetized object. When a permeant magnet is close to an object it’s magnetic field has an effect on the domains, it lines them with its magnetic field and magnetizes the object.

Magnetic Fields

            The magnetic fields travel inside the magnet from south to north, and on the outside the magnetic fields travel from north to south. The magnetic field affects any object with a perpendicular velocity. This is how the northern lights are created as the magnetic field of earth is perpendicular to the velocity of object except at the north pole of the earth where the velocity and the magnetic field are parallel and allow the object to pass through the Earth’s magnetic field and burns up in the atmosphere creating the colored lights.