Last week we tested the voltage increase of a magnetic flashlight given the intensity and number of physical shakes, along with the help of LabView software. The objective behind the experiment was Faraday’s Law: The induced electromotive force (EMF) in any closed circuit is equal to the time rate of change of the magnetic flux through the circuit (Wikipedia). In other words, the forward and backward movement of the magnet between the coiled wires will cause electrical currents to generate in the flashlight.
We were given a specific process on how to perform this lab. We would perform 5 tests, each running 30 seconds long, being sure to keep track of the number of shakes per each test. The first test was to measure the voltage, without shaking the flashlight at all. Next we would begin shaking the flashlight very slowly. After the second test, we realized counting the shakes wasn’t as easy as one may assume. The sound of the magnet shaking inside with the fast moving shakes of the flashlight was distracting. For us, it was easier that one person did the shaking, while the other counted the shakes and timed the 30 seconds (LabView was the timer so we simply just watched the computer screen). For the third test, we were to shake the flashlight a little faster. The 4th and 5th tests would increase speed more each time, by the final test we were shaking the flashlight as fast as possible.
After each voltage trial we made sure to record the data into the Excel spreadsheet. With the LabView program, we could close Excel, perform the next experiment being recorded in LabView, then open the saved spreadsheet in Excel and the new test results would be there. After we had all our data we found the sum of squares of the voltages using (v2). The sum of squares finds the average number between the points showing a line in regression the graph. In the graph, this shows the voltage points between each shaking intensity. In this experiment we found that more is more is more. The higher intensity shakes with a greater number of shakes showed more voltage generated. Below is a link to the excel spreadsheet.
This blog provides background to the experiment starting off with the crucial point of Faraday’s law and then goes into a very detailed step by step description of the experimental process. The excel sheet showcases the data in a precise format and the graphing makes it easy to interpret the results.
Great way to surmise the process of the experiment.
I feel that if I wanted to recreate the experiment at home I would use this as a resource.