MAgnets, Coils, and GeneratorsImportant Concepts:◊ Generators are vital to the production of energy. If there is energy there is probably a generator involved. Generators create electricity by changing the magnetic field within a coil. Typically a generator will incorporate some device which constantly passes a magnet through a coil to generate this electricity. ◊ Faraday’s Law are the most efficient generators have magnets travelling through coils at great speeds. Due to the high speeds of the magnet, the magnetic field changes much faster, generating more electricity. The connection between speed or rate, and voltage is known as Faraday’s Law (www.Britainnica.com). It is for this reason that when the magnet is placed on the inside of the flashlight and shaken at different speeds, different voltages are produced. ◊ In Sustainability It’s important to acknowledge that generators, although powered via fossil fuels have the ability to generate electricity from renewable resources. These renewable resources include nuclear energy, wind powered energy and hydroelectric energy. If a generator is to be considered renewable it must find a way to spin a turbine without the use of fossil fuels. To explore other renewable resources follow the link below. http://energy.gov/eere/office-energy-efficiency-renewable-energy◊Turbines ‘are a machine for producing continuous power in which a wheel or rotor, typically fitted with vanes, is made to revolve by a fast-moving flow of water, steam, gas, air, or other fluid.’ (Merriam Webster) ◊Magnetic Fields are ‘Regions around a magnet, electric current, or changing electric field in which magnetic forces are observable. The field around a permanent magnet or wire carrying a steady direct current is stationary, while that around an alternating current or changing direct current is continuously changing. Magnetic fields are commonly represented by continuous lines of force, or magnetic flux, that emerge from north-seeking magnetic poles and enter south-seeking poles. The density of the lines indicates the magnitude of the field, the lines being crowded together where the magnetic field is strong. The SI unit for magnetic flux is the weber.’ (Merriam Webster) Strength of Magnets (Opposite Poles): Magnets Repelling (Same Poles): |
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The Original Experiment Done In Class:Method One: One magnet in the inside moving up and down slow: Method Two: One magnet in the inside moving up and down medium speed: Method Three: One magnet in the inside moving up and down fast: |
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Some ideas for our experimentThe Experiment we decided on was very different from our original plans. We had hoped to create a device self propelled by magnets of opposite charge, which would spin around a coil and generate ELECTRICITY. This however proved to be far more difficult than we expected. Using a paper cup we ATTACHED magets to the inside and outside of the cup, held by three opposing charges. We placed this cup on a small poll set up like a football goal post hoping to put a copper coil in the center of the cup. The magnets on the outside of the cup were supposed to help rotate the device around the post via an OPPOSITELY charged magnet. We found it too difficult to suspend the cup correctly which was necessary in order for the device to spin. due to our difficulties we decided to turn our experiment into the flashlight one described below. The Experiment:Procedure: This experiment will test the effects of a magnet on the outside of the copper coil, on the inside of the coil and with no magnet at all. – To connect the flashlight to the NXT device, attach the ends of the two wires from the flashlight to the two different gator cables of the NXT. Connect the NXT to the computer via a USB cable and open up labview.Turn the NXT on by clicking the orange button; click my files, software files, generator lab, and then run generator lab to reach the voltage setting. – The average voltage from each method, conducted for 10 seconds, will be recorded as as a single trial. To collect data on labview simply click the play button at the top left of the screen and the data will automatically record for 10 seconds. – The voltage produced without a magnet will be tested first. This will be done by letting the flashlight sit without a magnet present. Only one trial of this method is necessary. – Then using the magnet, the amount of voltage generated from the outside is tested. The method for doing this is open to interpretation. Three different methods should be tested along with three different trials of each method. The magnet can be moved back and forth both horizontally and vertically along the coil, or along the bottom of the flash light. More than one magnet can be combined and used in any way to obtain a voltage reading. – The voltage generated from the magnet on the inside of the coil is then tested by placing the magnet inside the flashlight, covering the opening with one hand and shaking the flashlight back and forth with the same hand, allowing the magnet to pass back and forth through the coil. This may be done at various speeds to test for differences in voltage. This method should also be tried with two magnets instead of one. – Method 1: No magnet On inside Method 2: One Magnet on the outside Method 3: Two Magnets on the outside
Method 4: One MAgnet on the top and one being Shaken on the Bottom
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The Results:
The results of this experiment can tell us a lot about the function of generators. In method one no magnets were present, however the NXT device still detected some voltage. This method served as a control for the experiment; it showed a natural flux of voltage as detected by the device. Therefore if we obtained similar numbers when using a magnet, one might conclude the magnet was producing little or no charge. The second method, when a single magnet was shaken horizontally along the outside of the coil, little voltage was produce. The highest voltage reading from the three trials was 0.207 Volts; not particularly significant. Method three followed the same procedure as the second, however, now with two magnets on the outside. This method also didn’t produce fairly significant results. Out of the three trials, the highest voltage produced was 0.194 V. The next method, 4, produced a maximum voltage of 0.117 V in trial three. This method involved shaking a magnet horizontally along the open end of the flashlight while another magnet sat on the top of the flashlight next to the bulb. The next two methods produced the most significant amounts of voltage. In method five the magnet was placed on the inside of the flashlight. The highest voltage produced was in trial three with 4.082 V. It’s important to keep in mind however that the flashlight in this method was shaken relatively slowly compared to method six. In method six the magnet was also placed on the inside of the flashlight, however this time was shaken fast. This method produced a maximum voltage of 6.554 V. *Many different trials of each method took place with various different voltage, therefore the voltages presented here only represent the maximum voltages of a random single 20 second trial. What Does This Mean? – As you’ve probably noticed the voltages produced from method two, method three, and method four were all very similar. This is because in each of these methods the magnet was used on the outside of the flashlight. The greatest amount of voltage is produced when a magnet is passed through the inside of the coil. This is why the voltages were so high in methods five and six. Method six however, produced the highest voltage reading because the flashlight not only used a magnet on the inside of the coil but was shaken at the greatest speed. As mentioned previously, Faraday’s law dictates this principle. When a magnetic field changes, electricity is produced. If the field changes more rapidly then even more electricity is generated based on Faraday’s law. Therefore generators in the real world that want to produce large amount of energy Use turbines that will allow magnets to travel at high speeds Inside of a Coil. Our Trip the Dorchester Academy and Boston Tech Going to these inner city schools was a fun experience, we enjoyed sharing our findings and project with these two classes mostly because the kids at these schools payed attention and were in fact interested. It felt good to make a positive impact on kids who are going to be where we are now in a year or two, because we remember when colleges came in to talk to us and we know it impacted and we looked up to those kids because they could tell us what it is really like for them and not just what the school says the life of a student is like in and out of the class room. It was just nice to be able to say that we could have been able to influence a kid who is maybe lost as to what he or she wants to do or where to go to school, we know not all of them learned or cared but even if we helped just one of them then we did our job and that is a great feeling. Works Cited “Faraday’s law of induction (physics).” Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 24 Nov. 2013
“Magnetism.” Merriam-Webster. Merriam-Webster, n.d. Web. 13 Dec. 2013.
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