Over the last month in our Sustainability, Energy, and Technology Honors Seminar for Freshman class, a few groups have been focusing on designing and presenting science experiments to high school students. Our experiment, demonstrating Faraday’s Law of Induction using a flashlight generator, has come a long way from the beginnings of our ideas. Our group has started with the idea of recreating the Faraday’s flashlight generator lab we completed in class, using the NXT module, the Faraday’s flashlight, and the necessary cables. The plan was to show the students the correlation between the number of shakes and the amount of electricity produced.
However, after several brainstorming sessions, we came up with some additional ideas to make this experiment even more attractive, especially since we knew in the back of our minds that we would be presenting to the bored high school students. We thought it would be fun to show the students the original Faraday’s experiment, which he performed some 200 years earlier. Luckily, we already had all the materials we needed in the laboratory. By shaking the magnet inside of the Faraday’s flashlight and measuring the electrical current produced using the ammeter, we wanted to show how the electric current is produced inside the coil. We also wanted to demonstrate the nature of the electric current produced and how it alternates. We then decided to split our experiment into two halves: during the first half, we would show the students the alternating current occurring using simple technologies, and during the second half, we would show them the graph we had got when we used NXT voltmeter and recorded the measurements from it.
The graph, as we figured out, would then give students a further theoretical insight. To produce such a graph, we decided to use the raw data obtained by the NXT voltmeter. On the X-axis the graph read seconds and the Y-axis we put the readings from the NXT voltmeter module. The graph we have got was similar to the sine function as it was supposed to be.
The problem we then faced was that digital ammeters, which we wanted to use to show the alternating current at work, were not as good as we initially thought in demonstrating the alternating currents. What we needed was the zero-centered analog ammeter. Another issue with our experiment was that we could not control the magnet as it slid inside the tube in the flashlight. If we shook the flashlight too fast, no one really could see the alternating current as the digital ammeter just showed some constant value. On the other hand, if we shook the flashlight too slow the magnet tended to stick on one end of the tube, and when it moved, because of the friction, the movement was not smooth at all. We knew that for the successful presentation we had to fix the experiment, but we had no idea how to do that. After a discussion, we decided that it would be useful to take apart the flashlight and leave just the magnet and the coil with the wires so that we could control the movement of the magnet more directly. We also decided to test different digital ammeters and find the one that could depict the alternating current most accurately.
After finally fixing all the parts of our experiment, we then began working on the presentation itself. Through the brainstorming process, we decided that we wanted through the presentation to educate the students and spark their interest in electrical engineering, while at the same time stress how Faraday’s Law and the use of generators play a crucial role in sustainability and power generation in our world. Acknowledging the fact that the students might not know all the terminology, we made the presentation both simple and exciting. We put a lot of pictures there as well as we tried not to overburden each slide with information. On the first slide, we put pictures of a nuclear power plant, coal power plant, and hydroelectric power plant. We used the pictures to explain to the students how although all of the abovementioned power plants are powered by different things, they all share the same principle of converting kinetic energy into electricity using the generator similar to Faraday’s one. On the next slide, we tried to explain why is that the electric current that is produced by the Faraday’s Flashlight is an alternating current. Finally, we concluded our presentation with a visual representation of the alternating current produced, which looks similar to a sine function.

The actual presentation at the O’Bryant High School went well, although we did not have much time to talk due to class time limitations. Nevertheless, all of us enjoyed presenting. We all were a little nervous to present as it seemed to us as the culmination of our class work, but after getting over the initial fear, we felt remunerated seeing how children were fascinated by our experiment.