Final Unit Blog Reflection.

         
 It's finally that time of year: our final unit blog reflection! It's hard to believe that the year has gone by this fast. And we certainly ended on an interesting unit to talk about. In this unit, we talked about magnetism, magnets, north and south poles, compasses, cosmic rays, the "right hand rule", motors, the necessities of making a motor, electromagnetic induction, generators, and finally transformers. Also, some big questions that we answered were why do paperclips stick to magnets, how are the northern lights created, what makes a motor work, and finally, how do credit card machines work.
     
We first started off by talking about talking about magnets and magnetism. Remember, moving charges are the source of ALL magnetism. This concept is key to remember. Generally, electrons tend to spin in random directions; a cluster of these electrons moving together is called a domain. Before magnetism occurs, there is no net direction. However, when something comes into contact with a magnetic field, the domains will align in the same direction as that magnetic field. This net direction makes forwards and backwards distinguishable; these are called poles. The magnetic field inside of a magnet will run towards the north pole and runs away from the south pole. The magnetic field also surrounds the magnet and goes around from north to south. Like poles repel each other and opposite poles attract each other because of the field lines. Attraction is caused by the field lines running in the same direction and repulsion is caused by field lines pointing towards each other. We already know that compasses point north, but because of the knowledge we just acquired, we know that the compass needs to be magnetized for this to happen. Now, lets talk about why a paper clip will stick to a magnet. Originally, the domains in the paper clip are random. The magnet has a magnetic field. When the magnet comes close to the clip, the domains of the paperclip align to match the magnetic field of the magnet. The paper clip now has a north and south pole. The north pole of the paperclip is attracted to the south pole of the magnet. Thus, they stick together.
       
 The next thing we talked about were the northern lights. What this really is are cosmic rays- which are charged particles entering in the atmosphere. As we know, there is a magnetic field running around the earth. When the charged particles try to enter perpendicular to the magnetic field, they will feel a force that prevents them from entering the atmosphere. However, when the particles try to enter through the poles, they enter in a parallel fashion which will mean they feel no force. Thus, northern lights only occur at the poles. However, this means that people there have an increased risk of cancer because the cosmic rays can rip holes in the DNA. Now, lets talk about the affects on wire. Wires have a magnetic field. We can now where this magnetic field points thank to the right hand rule. If you point your thumb in the direction the current is running, your hand should then signify the way that the magnetic field wraps around the wire.

 Next, we talked about motors and even got to build one of our own. We learned that for a motor to work, it needs to have a current carrying wire and a magnet. For my motor, I used a battery, a coil of wire, a paperclip, and a magnet. We use the battery to carry the current. The coil of wire was our current carrying wire. Finally, the paper clip was used to complete the circuit and the magnet provided the magnetic field. Ultimately what happened was the loop of wire turned on top of the battery. This happened because the current carrying wire felt a force in the magnetic field from the magnet. The force the loop feels will cause a torque. This torque will cause a spin. You are turning electrical energy into mechanical energy. This running motor can be used to make a car, a fan, or a blender.

 One of the bigger topics we learned about was electromagnetic induction. We learned that this is when you have a loop of wire and a complete circuit. When you insert a magnet through or around the loop of wire, this causes a change in the magnetic field of the loop. This change ultimately induces a current. Now that we know about this, we can learn about why a traffic light changes when you reach an intersection. In the pavement, there is a loop of wire. On the bottom of your car there are magnets. As the magnets pass through the loop of wire, it changes the magnetic field of the loop. This change in the magnetic field induces a current in the wire. This current acts as a signal to the stoplights that a car has reached the intersection and the light needs to turn green. We can also learn about a generator. When the magnetic field of an object is continuously changing, a generator is made. The generator turns mechanical energy into electrical energy. This will work because the electrons are perpendicular to the magnetic field. This differs from a motor, because a motor turns electrical energy into mechanical energy and the wire must feel a force.

 Finally, we learned about transformers. Transformers are made up of two wires, the primary coil and the secondary coil. The powers are the same in these two coils. The number of turns the coils make is directly proportional to the voltage induced. The more loops there are, the more voltage will be induced and the less coils there are, the less voltage will be induced. AC current will cause the magnetic field to change in the primary coil because AC current runs in the primary coil. AC current runs through transformers. It is important that transformers use AC because otherwise a change in the magnetic field will not occur.

 Personally, I have felt that this unit has been relatively easy. The only thing I initially had a hard time with was learning how a motor worked. But after actually making a motor it made a lot of sense. I am a very visual person and it has been nice to do various experiments in this unit. Otherwise the material has seemed very straight forward to me.

 I feel that my efforts to class and homework have, if anything, slightly increased this semester. I find myself more attentive in class and have felt that as a result my quiz scores have improved. I only hope that this will reflect on my unit test tomorrow. It always seems that I am fine throughout the unit but the day of the test I become overly stressed and end up not doing as well as I could. I do think that my persistance in class this unit has helped me. I still also feel like I take advantage of conference period when I need it. My confidence has also improved because when I answer questions I feel much less stressed out and much more at ease. Ultimately, my goal is to end this school year with a bang. I want to try my hardest on the final exam and get great results for my final grades. I plan to study all the material and take advantage of the review. Hopefully, the material from last semester will come back to my brain. I will try my hardest and ultimately that is all I can do.