UNIT 7: Blog Reflection

Unit Seven ended much quicker than Unit Six. In this unit, we discussed everything about magnetism (poles, fields, domains, etc.), transformers, current, generators, and so much more.

Topics:

Magnetism:
The first essential question we learned in this unit was "why does a paperclip stick to a magnet?". By the end of this, I will answer this question.

The idea of magnetism is basically moving charges that cause objects//things to be magnetic.

To understand this ideology, we learned a lot of smaller components about this. 

A domain is a cluster of electrons all spinning the same way. At first, a domain can be unaligned meaning that the cluster of electrons are all spinning in different directions, but magnetism causes the domain to be aligned.

After learning this, we learned about magnetic poles. Magnetic poles are each of the two points or regions of an artificial or natural magnet to and from which the lines of magnetic force are directed. In the real world, we call these poles the south pole and north pole. These two poles are obviously on each end of a magnet. 

With poles, there is a specific way that magnets will connect based on their side. Previously, we learned that unlike poles (for example: the north and south pole) attract and like poles (such as north and north or south and south) will repel. The way we can tell whether the poles are attracting or repelling is by their field lines. In unlike poles, the field lines will run in the same direction while with like poles the field lines will point in opposite directions like in the image below.

 

Knowing this information, we can understand the question mentioned above "why does a paperclip stick to a magnet?" This can be explained in four steps:

1. The domains in a paperclip are random (because it is not magnetic...yet!). A domain is a cluster of electrons that are spinning in the same direction.
2. A magnet has a magnetic field which is a region around a magnetic material or a moving electric charge within which the force of magnetism acts. 
3. When the magnet is close to the paperclip, the domains in the paperclip become aligned to math the magnetic field of the magnet.  
4. After this, the magnet now has a magnetic poles (north and south) and the north pole of the paperclip is attracted to the south pole of the magnet because opposites attract and that is how the paperclip sticks to a magnet.

We learned a couple of random facts that would help us understan magnetism a little better. Things such as:

The force between any two charged particles depends on the magnitude of the charge and their distance of separation. 

The force due to the motion of charged particles is called the magnetic force.

Electrical and magnetic forces are part of the same ideology of electromagnetism as you can tell because the root is electro and the ending says magnetism.

An electromagnet is a current carrying cool of wire and the strength is based on an increasing or decreasing current.

Still on the topic of magnetism and electromagnetism, we learned the essential question of "how does a credit card machine work?"

To answer the question, you need to answer it in four parts:

1. A credit card has a magnetic strip on it that has different magnetized sectors forming a code

2. There is code on the magnetic strip. 

3. The reader has different coils of wire that line up and there is voltage induced in it when the strip slides through the machine.

4. The computer screen interprets electric signals back to coding and takes your money.

That was a culmination of individuals objects magnetized with other objects. 

Transformers

Next, we learned about transformers.

Transformers are machines that transfer energy from a primary to a secondary circuit. Transformers have a more efficient arrangement. A transformer, in simpler terms, is used for increasing or decreasing voltage.

Because it has alternating voltage: we must use the equation

Primary voltage/number of primary turns equals secondary voltage/number of secondary turns.

The problem given will always tell which one is the primary and secondary but sometimes based on the information given, they require you to know which is which.
A primary circuit is the circuit that is closest to the outlet and inputs energy. The secondary circuit is the one which is closest to the device and releases energy. If you've ever seen a computer charger, you notice that it comes with a box...have you ever thought about the use of that? That box is a transformer that allows your computer to charge. The way a transformer looks like is just two coil of wire just like what you see below:

Alternating current or AC runs through the primary coil which causes the whole thing to have a change in the magnetic field. DC or direct current cannot be used for a transformer because the current it produces only moves in one direction. AC current continuously changes the direction of the current, which is what causes change in the magnetic field in the first place. The number of turns in the wire is directly proportional to the voltage induced. The more turns in the wire, the more voltage there will be. The less turns the less voltage there will be. If the secondary has more turns the primary. That is why we use the formula that I wrote above.

We also learned about step up and step down transformers. A step up transformer means that the secondary circuit will have more turns than the primary.  If the secondary has less turns than the primary it will have less voltage than the primary and the voltage will be called a step down transformer.

Difficulty: 
This unit was the second hardest unit of the year for me. Once again, there was a lot more material that we covered in a small amount of time, less blog posts to help me, and a change in teaching styles as Ms. Lawrence left. I found that memorizing all the big problems and having to remember all the different equations in order to solve a problem right was hard for me.


Problem-Solving Skills, Effort, and Learning:
Effort in class: I don't think I was able to contribute in class as I have in the past because this unit was really difficult and I usually learn better by intaking the information first and then giving it back verbally but it took me a while to understand the concepts.
Homework: I learned a lot from doing the homework problems because in this unit the outside of class assignments were what tied everything together for me.

Goals:
Do well on the test tomorrow and do well on the final by studying the videos, reviewing podcasts, blogposts, and notes.
Connections:
Many of the connections that I saw outside of class were already put into Part A. 
Podcast:
In this unit we did not do podcasts. Sorry!