final unit post!!!

We began the semester off learning about magnetism. For, the source of all magnetism is electrically charged particles. When these particles align when the spin or have aligned domains, it causes magnetism. When a magnet is magnetized it has north and South Pole and a magnetic field. Magnetic field lines run from north to south outwardly and south to north inwardly. They explain why only opposite poles attract since the fields lines are running in the same direction. A common example of this concept is magnetizing a paperclip. To begin with the paperclip is neutral however when it comes near the magnets magnetic field, it causes the paper clips domains to align causing polarization. Since the internal field lines are in the same direction, the paper clip sticks. Magnetic fields also work with the earth. They protect us from cosmic rays. However, since the cosmic rays can only feel a force if they perpendicular to the magnetic field, the cosmic rays that hit the poles are parallel and thus the particles do not feel a force and can enter the earth’s atmosphere.

Next we learned about motors. Motors convert electrical energy into mechanical energy. They work when a current carrying wire is exposed to a magnetic field. Since the magnetic field is perpendicular to the current, it feels a force and thus resulting in a torque for the wire to spin easier and for longer. Such use of this method has been used from lawn mowers to fans.

Next we learned about electromagnetic induction. This means that the change of magnetic field causes current. This concept is applied to many of useful everyday technology such as traffic lights or credit card machines. For instance, within the credit card is a series of magnets and within the credit card machine there is a loop of wire. The magnets cause a change in the magnetic field causing current, which sends a signal to the credit card machine.

Finally we learned about transformers. Transformers affect how much current and voltage goes into appliances or even our households. There are two types of transformers step up and step down. We use step up with our power lines. Since current causes heat and the power lines could become overheated, there is less current going through them than what it takes to run a household. However the current goes through a transformer which has a primary coil which it enters and a secondary coil which it travels to the house In order for the transformer to work it must have AC current for there to be a change in the magnetic field. For the house there are less coils of wire in the primary coil than the secondary. The secondary produces more current for the household and creates efficient energy.

I really enjoyed this unit and I have come to understand it better than I have most. My greatest problem with this unit was figuring out AC currents affect with magnetic fields. However, I have grasped it more strongly due have to work on the podcast that deals with that particular topic. To improve in the future, I hope to try to apply this unit to more everyday activities instead of just trying to memorize the principles. Otherwise, it has been one of my favorite units and it has been a electrifying final unit.