Purpose: Which fruit will produce the most voltage
Hypothesis: A lemon will produce the most voltage when tested
Materials: 1 voltmeter, 2 ires, 1copper strip, at least 3 fruits/vegetables
Procedure: 1. Take fruit 2. Put copper strip and galvanized nail into fruit 3. Attach one wire to the nail and one to the copper 4. Attach to voltmeter 5. take reading 6. Repeat
Reasoning(why): I think that the lemon will give off the greatest charge because it has a lot of citrus in it and citrus has lots of electrolytes
Setup photo and results:
Large orange: 0.3 volts
Small orange: 0.4 volts
Lemon: 0.8 volts
Pickle: 0.9 volts
Pear: 0.5 volts
Potato: 0.5 volts
mixed fruit/ vegetable juice: 0.4 volts
Observations: Voltmeter gauge didn’t stay at one number(bounced around), more fruits = more volts, fruits with more citrus produced more volts, LEDs are very difficult to light with fruit, my hypothesis was wrong in that lemons were not the highest voltage fruit/vegetable(in fact it was a pickle for us).
Prompted questions:
- What is causing electrons to flow in this experiment?
When the citric acid in the fruit reacts with the zinc in the galvanized nail draws electrons toward the copper and the copper is conductive so the electrons travel from the fruit to the copper and through the wire into the voltmeter or whatever you have hooked up to the other end of the wires (motor,LED, etc)
- what are the independent, dependent, and controlled variables in this experiment?
The independent variable: This is the fruit that we use in the experiment.
The dependent variable: We are measuring the voltage outputted by certain fruit.
The controlled variable: We always used the same wires, copper sheet, and galvanized nail. We were also measuring the voltage the same way for all fruits.
- How could we modify the experiment to improve our results?
You could add more fruits to make a fruit circuit, therefore, outputting more voltage.
- What could be sources of error or uncertainty in our experiment?
Some sources of error are that you might not connect the wires to the right parts on the voltmeter which makes it appear like the fruit has no charge when that is not the case. Some sources of uncertainty could be not factoring in the size of the fruit, and how worn out the other materials were.
- How can you use this in your everyday life?
You could, in theory, make a big enough circuit out of lemons you could make enough voltage to power a lightbulb.
Additional questions that I have after doing the experiment
What would happen if we used a battery to charge up the fruit beforehand?
What would happen if we used dried versions of the fruits(dried apple, dried banana, dried mango, etc)?
If I recreated this experiment on a bigger scale, could it be a clean sustainable source of energy?
how big of a lemon would I need to (in theory) power a house, a village, a town, or a city with this same setup?