The purpose of the experiment is to discover if any fruits and vegetables can generate an electrical charge, which ones, and which generate the greatest electrical charge. By using a variety of fruits and vegetables, the students will learn the difference between electric charge and electric conductivity. The experiment starts with the premise that potatoes will generate a greater charge than other fruits and vegetables. The result of the experiment will either prove or disprove this hypothesis. Use lemons, potatoes, bananas and apples for comparison.
Using an electric multimeter, available at hardware and home-improvement stores, the students perform two measurements on each fruit and vegetable. They log the information into a chart and create a graph to compare their findings. Using the micro amp scale on the multimeter, they determine the flow of electricity, or its conductivity, and record their findings. Next, they set the multimeter to the ohms scale to measure the resistance, or electric charge, in each item. Measuring the resistance is done first with the probes close together in each item, then spacing the probes further apart.
After performing the tests to determine the conductivity and charge, as well as the difference in the charge, or resistance, based on the distance between the probes, the data is charted and visually graphed to analyze the findings. By looking at the information, the data shows that the lemon has the strongest flow of current and the potato has the weakest. However, the potato has the highest resistance, or charge, when the probes are close. The students will be able to analyze which fruits and vegetables have a high level of conductivity or charge, and how the placement of the probes affects the findings.
Upon studying and comparing the results of the experiment, the students find that their original hypothesis, that the potato has the greatest charge, is incorrect. In fact, none of the fruits or vegetables have much of an electrical charge. They also discover that fruits and vegetables with a high water content conduct more electricity, and that acidic fruits have a stronger flow than non-acidic fruits and vegetables. In the end, the results, once graphed and analyzed, will prove the original hypothesis incorrect.