We began this unit with learnig about domains. Domains are a cluster of electrons spinning in the same direction. On a magnet there is a north and a south pole. The North attracts the South but repels the north. How does a paperclip stick to a magnet? A a paper clip has random domains. The magnet has a magnetic field. WHen the magnet is close to the paperclip the domains in the paper clip will align with the magnetic field in the magnet. The paperclip now has a north and south end. The north pole of the paperclip is attracted to the south pole of the magnet thus the paperclip sticks to the magnet. When drawing a picture of the magnet on earch the geographical North has the south pole of the magnet whereas the geographical north has the north pole of the magnet. All moving charges will feel a force in a magnetic field when they are moving perpendicular to the magnetic field. We then made a motor. A motor is made up of a battery, wire, paperclips and magnet. The battery sends a current through the wire, the wire carries current and reacts to magnetic fields the paperclips conduct electricity and the magnet acts as the force. The reason a motor of a fan for example works is because the motor of a fan consists of a magnet and a currenct carrying wire. The magnetic field exerts a force on the wire. this force will cause a torque. the torque will ultimately start the wire moving if the wire is perpendicular to the magnetic field. Once the wire is turning the fan blades will turn. When then learned about electromagnetic induction. Electromagnetic induction's principles apply to why stop lights know you are there, why credit card work, and how a metal detector works at an airport. This is the answer to why a credit card machine works: there is a coil of wire inside the maching (no current). On the credit card are a series of magnets. When the magnets pass through the loop of wire the magnetic field will change. This change will induce a current. Finally the cirrent will act as a signal to tell the computer what the credit card number is. We then learned about a transformer. In order to know exactly what a transformer is you must be aware of this equation: # of turns in primary/primary voltage=# of turns in secondary/secondary voltage. In the primary voltage you establish the AC current as the current goes back and forth you are changing the magnetic field. This will also change the magnetic field of the secondary loop inducing a current. If we increase the # of turns in the secondary, the voltage will increase if we decrease the # of turns in the secondary the voltage and current decrease. In other words AC current is used because the alternation which changes the magnetic field which induces a current. Generators are mechanical energy in and electrical out in a generatir you are moving magnets over wires which changes the magnetic field of the wire which induces a voltage, which causes a current, the current is used to run a lightbulb or blender. There are two right hand rules. On of the rules is that your index finger represents the current your middle finger represents the magnetic field and the thumb represents the direction of moving charged particles. ALso big appliances use step down where as smaller appliances use step up.
My effort towards class is pretty consistent and I feel that I am a persistent participant. I also go in early when I feel that it is necessary. And my effort is reflected in-group work especially, which is a time that I am fully involved with the activities. I do my homework every night. By going in early and asking questions in class I feel that I have strong communication. And my creativity was reflected when making the podcast, and how my partners and me would use real life examples and then further discuss them. My goal for the next unit is to make sure I study before each quiz and go in early to be tested on my knowledge of that particular unit. The connections I make with everyday have been pretty obvious in this unit. these connections include why credit card, airport security and traffic lights work (electromagnetic induction) also we learned how motors work and why paper clips stick to magnets.
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