Last week’s lab experiment involved the application of what we learned as Faraday’s Law, which required the generation of electricity in a flashlight-like object; within this tube, a magnet traveled back and forth between the wire coils and thus created an amount of electricity stored in the capacitor for later use as illumination. Prior to beginning the experiment, we learned that the more times we shook the tube, the more electricity was to be generated. After hooking the flashlight to the computer for result recording purposes, the computer would read the electricity in the tube 30 times (or every second) for each trial executed, thus creating a waveform chart of results. We were instructed to record five different trials with the tube; for the first trial, we were not supposed to shake the tube whatsoever and observe the voltage results displayed by the computer. For the four following trials, we were to increase the intensity of our shaking and subsequently observe these results as well.
The first trial involved resting the flashlight tube upright on the table and running the generator program as we simply sat by and watched the voltage results appear on the computer
screen, despite the fact that we were not shaking the tube, therefore not creating new electricity between the magnet and the tube’s coils. According to our results, which can be seen in Fig. 1, no negative voltages were recorded by the system, yet the visual readout on the screen showed how the voltage varied up and down on the chart in the positive number range. Worrying that we had made an error in our first trial, we repeated this procedure, this time placing the flashlight tube on its side; to our relief, the results were similar, and likewise did not produce any negative voltages. With our results transferred immediately onto a Microsoft Excel sheet, we then calculated the square-sum of the first trial’s results and discovered it to be .955, although we were unclear as to how low this would prove to be.
For the second trial, we concluded that we should shake the tube exactly 10 times within the 30-second timespan, keeping in mind that our shake intensity was meant to be low at this point in the experiment. While some of the voltage result pairs were recorded as if the object had been resting, other readings were dramatically different, some dropping low into the negative range as can be seen in Fig. 2. One aspect of this trial that should be noted is the slight inconsistency of our shakes; some were either light in intensity while
others were harder, and they were irregularly spaced throughout the 30 seconds. After calculating the sum-square in our Excel sheet, we found it to be a drastic increase from the first trial, jumping from .955 to 32.614. The third trial yielded similar results in its dramatic drops in negative numbers as we shook the tube a bit more vigorously 20 times. For this trial (as shown in Fig. 3), the sum-square came out to be 81.697, which is an interestingly high increase from the second trial due to the fact that the recorded voltage results were not too different.
The fourth trial involved more intensity and 30 shakes within a 30-second time period. Our results for this trial can be seen in Fig. 4 as the voltage spikes towards the end of the 30 seconds, mysteriously jumping up to 6.477 all of a sudden; perhaps this is because the
magnet had continuously created energy and it had all been captured for recording at once by this point in the trial. After this jump in voltage, the numbers fall drastically back down despite the constant intensity and spacing between the shakes. Interestingly, the sum-square of this trial was calculated to be 44.447, significantly lower than the sum-square of the more drastic results from the third trial.
For the fifth and final trial, we increased the intensity of the shakes and their frequency to 40 within the 30-second timespan. As we tried to get a feel for how often we should shake the tube to reach the goal of 40 shakes in this time period, our shaking speed was off at the beginning of the trial, as evidenced in Fig. 5. After this slight hiccup in our experiment, we reached a steady shaking speed and the recorded results leveled out to what we had seen thus far to be “normal.” For our final sum-square calculation, the result jumped up yet again to its highest peak of 143.9.
In conclusion, we believe that the only trial that was off in its success was Trial 4 due to its surprisingly smaller results and sum-square despite the increase to 30 shakes. After generating all of this electricity by shaking the tube so that the magnet would travel back and forth through the metal coils inside, we pressed the rubber button and were blinded by the blue-
fluorescence of the light bulb. The next time you fall asleep with your emergency flashlight on your bedside table, consider the process of voltage generation you must go through to have your safety light!