Download Fruit and Veggie Batteries: Finding Current, Voltage and Resistance

Fruit and Veggie Batteries: Finding Current, Voltage and Resistance in
Fruit and Veggies
Name: ________________________ Date: ______________ Block: ________
Objective: In this activity, you will learn how current, voltage and resistance react in fruits and
vegetables.
Purpose: The purpose of this experiment is to determine the electrical voltage, resistance and current
of different fruits and vegetables.
 to find out which fruits give the highest voltage outputs.
 to find out if the separation of the electrodes affects the voltage output and current.
 Examine the resistance across different fruit and vegetables.
Hypothesis: Which fruit/vegetable will have the greatest resistance? Which fruit/vegetable will have the
greatest voltage? Which fruit/vegetable will have the greatest current? Explain.
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Materials:
 Fruits or vegetables: lemon, orange, apple, kiwi, grapefruit, potato, sweet potato
 Electrodes: copper wire and nickel wire
 Multimeter
 Alligator clips
Procedure:
1.
2.
3.
4.
Roll the fruit a little to make it a little juicier in the inside.
Insert one electrode material into the juicy part of the fruit.
Insert a second electrode into the juicy part of the fruit, but not so the two electrodes touch.
Voltage measurements:
-Measure the voltage of several different fruits/vegetables. USE DATA TABLE 1
Set the Multimeter so that it is measuring DCV (Direct Current Voltages). The 200m
setting will give voltage readings up to 2.000 volts. If the readings are too high or too
low, just change the dial to an appropriate setting. Since it may be hard to maintain a
solid contact with the pointed Multimeter probes, it might be better if you use a pair of
alligator clip leads and attach one side to the end of the pointed probe and clip the other
end of the lead to the electrode. If you get a negative voltage reading, reverse the clips on the
electrodes.
5. Current measurements:
-Measure the current of several different fruits and vegetables. USE DATA TABLE 1
When making current or amperage measurements, turn the dial on the Multimeter to
DCA (Direct Current Amperage) and set the dial at the range setting most appropriate for the range of
current readings you are experiencing. The 200 μ is the most sensitive,
which means that it will record the smallest currents while the 200 m is the range for the
largest currents.
6. Calculate the resistance of the fruits and vegetables using Ohm’s Law, V=IR. USE DATA TABLE 1
7. Does the distance affect the current, voltage and resistance?
Move the electrodes (anode and cathodes) different distances apart from each other and measure
the current and voltage. Then calculate the resistance. Use Data Table 2
Data Table 1:
Fruit/ Vegetable
Voltage(V)
Current(I)
Resistance(Ω)
Data Table 2:
Fruit/Vegetable
Separation (cm)
Voltage(V)
Current(I)
Resistance(Ω)
Data Analysis:
1. Which of the fruits and vegetables had the greatest resistance?
2. Which of the fruits and vegetables had the greatest current?
3. Which of the fruits and vegetables had the greatest voltage?
4. Does the insertion depth of the electrodes affect the voltage and/or current?
5. Does the angle of insertion of the electrodes affect the voltage and/or current?
6. How does having the electrodes touch above (or inside) the fruit affect the voltage and/or current?
Conclusion: What fruit worked the best?________________ Were you correct? Why, or Why not?
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Extension:
1. Using alligator clip leads, make a series set of fruit cells and see what
maximum voltage you can get.
2. Using alligator clip leads, make a parallel set of fruit cells and
determine what the largest current you can get is.