Over the course of 3-4 weeks since we've gone deeper into Physics and learned about motors, generators/transformers, induced currents and magnetic fields and so on. Specifically, we've dug deeper into the Electromagnetism Unit. The next set of learning goals we were assigned to master are as follows:
EM9. I can describe the properties and interactions of magnets.
EM10. I can describe how the magnetic domains are arranged in a magnetic/non-magnetic material.
EM11. I can explain the connection between electricity and magnetism (electromagnetism).
EM12. I can outline the difference between DC/AC current and its uses
EM13. I can explain why the Earth behaves like a magnet and the consequences of it.
EM14. I can explain the importance of grounding wires and using fuses/circuit breakers.
EM15. I can explain how an electromagnet works and cite applications for them.
EM16. I can explain how a simple motor works (parts and function).
EM17. I can describe how a generator and a transformer work.
EM18. I can explain the importance of transformers to power grids.
EM19. I can explain methods of power production and distribution.
EM20. I can describe the differences of 110v/220v and main advantages and disadvantages of each.
EM21. I can describe the advantages and disadvantages of electrical energy.
I will explain them in this post.
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EM 9: I can explain the properties and interactions of magnets.
To determine if a material is magnetic then it might have these basic properties:
- Must attract iron and other materials that contain iron in its composition
- Magnets either attract or repel to other magnets
- When swung freely on a string, the material will point north
You may ask yourself why the magnet points North as you can see while looking at a compass. Simply, this is because of the two poles that the Earth contains, the North and South pole. But why the North and not the South? Basically, there's no certain explanation for this. But experts say that its because of the response due to the closest magnet and the Earth's magnetic field.
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(http://www.chainbow.com/images/compass.jpg)
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EM10. I can describe how the magnetic domains are arranged in a magnetic/non-magnetic material.
The magnet domain is the region in a magnetic material that which has an only magnetization. In a magnet you can notice that the domains all align with each other and point in one single direction whereas a non-magnetic material is not aligned and points to whichever direction possible. Here is a picture to explain to you:
(http://www.magnet.fsu.edu/education/tutorials/magnetacademy/magnets/images/magnets-domains.jpg)
As you can see the domains in the magnetic material are aligned and pointing at one direction
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I can explain the connection between electricity and magnetism (electromagnetism).
Simple enough, wherever you have an electric current you also have an magnetic field, thus being magnetism. This is because the electric current that flows through simple and complex circuits induce (remember that word) a magnetic field. This combination is called ELECTROMAGNETISM, cliché enough to remember...
Where do you see electromagnets? Think about those monstrous car lifters at junk years. The giant magnet is turned on by a switch and by the induced current, the magnetic field is induced, and picks up the car. It moves towards the large container and drops the car inside as the magnet is turned off by the same switch.
You can intensify how strong the magnet is by adding more loops of the wire around the metal since the more the wire, the stronger the current. This so called coil is a solenoid.
(http://www.google.com.br/imgres?um=1&hl=pt-BR&sa=N&rlz=1C1SKPC_enBR342&biw=1024&bih=677&tbm=isch&tbnid=j_G86QhbeClCaM:&imgrefurl=http://iscudyog.tradeindia.com/elliptical-electro-magnet-261248.html&docid=oth4I-wdYk5VqM&imgurl=http://product-image.tradeindia.com/00261248/b/0/Elliptical-Electro-Magnet.jpg&w=240&h=240&ei=SkWoT82JG6mZ6AGM8IjLBA&zoom=1&iact=rc&dur=270&sig=104074022357354064336&page=2&tbnh=153&tbnw=153&start=13&ndsp=17&ved=1t:429,r:8,s:13,i:120&tx=72&ty=71)
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12:
I can outline the difference between DC/AC current and its uses
The currents are a tricky concept in the world of electromagnetism. There are two types of them called the AC (ALTERNATING current) and the DC (DIRECT current). They both serve handy to different types of things. Here are their descriptions:
ALTERNATING CURRENT:
The alternating current have its electrongs reverse their direction constantly. Such current is induced when the conductor alternates in and out of the magnetic field (in and out). By the change in direction of the domains of the magent present in the situation, the current is induced thus electricity is made.
Alternating currents are perfect for situations in which the lights go out in your house or in more severe cases, a hospital. Since you induce a current (you don't need electricity if you an alternating current) you are able to produce the energy sufficient to run the entire hospital until the lights go back on.
DIRECT CURRENT:
The direct current does exactly what its name says; the current is in a direct flow (one single direction). This can be induced by a power source such as a battery, or by a changing magnetic field. Your remote control for your television, the alarm clock beside your bed and your cellphone all need a direct current because they are equipped with a power source (battery).
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EM13:
I can explain why the Earth behaves like a magnet and the consequences of it
It shows up in many science fiction movies that the Earth is protected by its Magnetic Field. However, this is not at all a lie, but rather as solid as the bar magnets. The Earth has its two poles (north and south) in which produce a magnetic field that protects us from space harm.
Now how does it protect us? Imagine that big, bright, scorching hot star that lights the Earth every day, the Sun. Its harmful blasts, known as solar wind, which are electric particles from the sun, that occur as your read this elegantly made project travel the millions of trillions of miles towards us and attempt to penetrate through our atmosphere, enabliing temperatures unknown and fatal to mankind. We wouldn't be here today if the Earth hadn't had its Magnetic Field. Imagine the field as a giant shield that blocks the harmful rays.
It hasnt been discovered yet how we do have this field that surrounds us, but the answer isnt far from our grasp.
The magnetic field also brings some beauty, however, like the auroras. They happen when a bit of solar wind particles gets through the field and react to the atoms in our atmosphere, which give out these wonderful lights.
http://www.google.com.br/imgres?um=1&hl=pt-BR&sa=N&rlz=1C1SKPC_enBR342&biw=1024&bih=677&tbm=isch&tbnid=vfUwW4e1bNpnwM:&imgrefurl=http://theboldcorsicanflame.wordpress.com/2011/06/14/giant-breach-in-earths-magnetic-field-discovered/&docid=1sGYEqXxMqrYiM&imgurl=http://theboldcorsicanflame.files.wordpress.com/2011/06/earth-magfield.jpg&w=1600&h=1200&ei=WEmoT_XXFajF6gHjxqi1BA&zoom=1&iact=hc&vpx=724&vpy=196&dur=703&hovh=194&hovw=259&tx=165&ty=118&sig=104074022357354064336&page=1&tbnh=141&tbnw=185&start=0&ndsp=15&ved=1t:429,r:4,s:0,i:81)
The magnetic field also brings some beauty, however, like the auroras. They happen when a bit of solar wind particles gets through the field and react to the atoms in our atmosphere, which give out these wonderful lights.
(http://www.nossorumo.com/155/conhecer-a-aurora-polar)
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EM14:
I can explain the importance of grounding wires and using fuses/circuit breakers
Electric shocks are hazardous dangers we are exposed to daily given the right mistakes we might make with electricity. However, man has already safe-proofed the deadly side of electricity by using such concepts known as the grounding wires and fuses.
This is a groundwire:
(http://www.google.com.br/imgres?um=1&hl=pt-BR&rlz=1C1SKPC_enBR342&biw=1024&bih)
As you can see, it has that third metal pin on the top. Why is it important for some appliances (if not all) have this life saver? It takes the kinky overload of charges that are not wanted, and take them directly down to the ground and safe from you. Electric shocks produced by the extra charges can be leathel since they disrupt some important signals in your body which can cause you to faint or sometimes, die. So best to have one of these around because its better SAFE than SORRY.
The other life saver is known as the FUSE. Sometimes in your house, you need to plug in your alarm clock for school, your cellphone charer for your phone to be fully functional the next day, your lamp, just in case you might get up in the middle of the night, and the other appliances you want to have in hand. However, you only have one plug. Needless to say, many of us will just find extra adaptors and plug all of them in anyway. This is dangerous. Because of the excessive appliances, a fire might happen. But luckly some adaptors have a fuse which melts when theres too much heat and interupt the current. The only thing you should be bummed about is buying a new adaptor.
Circuit breakers, well, break the circuit. They do this when there is too much heat and automatically turn off the current.
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EM15:
I can explain how an electromagnet works and cite applications for them
The electromagnet is solemnly made out of ferromagnetic material (like a nail) and a solenoid. It is basically a magnet that can either be turned on or off.
The electromagnet works by inserting the ferromagnetic material through the solenoid. This happens because of the produced magnetic field which can be intensified by increasing the number of loops of wire on the solenoid, using a stronger ferromagnetic material or increase the current of the solenoid.
Not noticed by manym the doorbell utilizes an electromagnet that, when turned on, makes the hammer vibrate making the sound we are familiar with. Microwaves also have this.
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EM16:
I can explain how a simple motor works
A motor is pretty much present in most of today's appliances such as your car and the fan. It is built up of three main parts which are the brushes, the commutator and the armature. The brushes of the motor are the two metal pieces at the side that bring the current of the power source to the commutator in which sends it to the armature which is in the middle of two very powerful magnets. As the current turns on a magnetic field is induced. As the commutator spins, the gap in which divides the two metals causes its spining to reverse as it falls slowly by the inertia of its previous spin. By the change of direction, the motor is able to keep full constant movement.
(http://www.google.com.br/imgres?q=simple+motor+diagram&num=10&um=1&hl=pt-BR&rlz=1C1SKPC_enBR342&biw=1024&bih=677&tbm=isch&tbnid=n_9HyfCgAOMpdM:&imgrefurl=http://www.physicsforums.com/showthread.php%3Ft%3D329603&docid=mDoPTP5AkmX6UM&imgurl=http://library.thinkquest.org/15433/unit6/motor1.gif&w=289&h=183&ei=0GayT6aZHoSk8gTtkb2HCQ&zoom=1&iact=hc&vpx=122&vpy=179&dur=2629&hovh=146&hovw=231&tx=130&ty=92&sig=102062817251230521647&sqi=2&page=1&tbnh=123&tbnw=195&start=0&ndsp=13&ved=1t:429,r:0,s:0,i:69)
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EM17:
I can describe how a generator and a transformer work
The generator and the transformer are two incredibly different machines.
The GENERATOR simply generates the energy by the induced current and the magnetic field. It happens by the induced current (you can do this by getting a conductor and putting it in and out in the gap between two magnets). By the creation of an alternate current, the generator needs a crank to keep the movement going so you can say that the generator transforms kinetic energy (which is energy by movement) into electric energy. Generators can be seen in many natural power plants such as hydroelectric plants and wind turbines which convert movement into energy.
A transformer is what takes the energy the generator produces to our homes efficiently and speedy. Isnt it strange to think that the thousands of voltage created by the generated divides into 110 and 220 V in our homes? The logical explanation to that twist is that the transformers (not the robots) turn the large voltage into a smaller ammount and equally divides it to our homes.
The transformer consists of an iron core and wires. Look at the following diagram:
As you can see, there are twice as many loops of wire ni the first "leg" of the iron core. This is what we do when we want a higher voltage, so in proportion we put 8 loops or 16 loops in the first coil, and 4 or 8 loops in the second.
If we wanted to lower the voltage, we'd do the exact opposite. This is how the energy in our hourse is a minimum of 110V, safe, efficient, and quick process.
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EM18:
I can explain the importance of transformers to power grids
Transformers are essential to the power grid. Think of it this way...
As I told you before, the more the resistance and current of a wire, the higher the temperature which releases heat; a type of energy. So basically, we are losing some of the overall energy that flows in the conductors. The transformers simply raise the voltage (up to 800,000v) but not the current, which makes the temperature a limiting level which doesnt waste too much energy and is quick enough.
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EM19:
I can explain methods of power production and distribution
There are many ways to produce power. Some of these ways may be harmful to the environment and to us while others are "clean" and are ecofriendly. Two of these safe ways are Hydroelectric Energy and Wind.
Hydroelectric energy is effective in all grounds since it produces a large amount of energy that can provide energy for an entire city. It uses movement of water, kinetic energy, to transform it into electric energy. However, building a hydroelectric plant is the issue; it is very expensive and will ruin an area because the river where it will be built will most likely flood. To this problem, all species of animals must be evacuated before the iniciation of construction begins.
The power distribution of the hydroelectric power plant consists of the transformer, that takes the energy all the way to the people, and is safely transformed into usable 110V and 220V ranges.
The other method, using the wind, is also effective however picky on its location since the wind must be constant for the energy to be produced. You may see this in various deserted areas or large fields. Given its size, the poles must be in a spacious area. In the right amount, energy can be produced in limitless levels.
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EM20:
I can describe the differences of 110V/220V and main advantages and disadvantages of each
It is a rather controversial topic to choose either 110V or 220V. The truth is that the 220V is more efficient than the 110V since it focuses more on energy rather than energy loss. However, most of our appliances run solemnly on 110V outlets, and will either burn or stop working if plugged into a 220V outlet.
The advantages of a 220V is that there is more energy so the appliance will be better and more powerful. However, the more the energy, the bigger the heat, and it may cause the appliance to burn out in a short period of usage.
The avantages of the 110V is that it is commonly used and wont produce as much heat as the 220v. However, it is less efficient because it powers less than the 220V.
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EM21:
I can describe the advantages and disadvantages of electrical energy
Electric energy is a very useful, efficient and clean way to power up our homes. It comes in virtually limitless amounts, can be synthesized and serves as a worldwide need. However, the methods in which we create energy are sometimes hazardous to us, animals and nature. Nuclear Power plants and fossil fuels are harmful to us and our planet, so slowly, it brings us to our own doom. Even though the clean methods of energy are at hand, they are way more expensive than the harmful, cheap, and prodcutive methods.
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