[sci] Report Of Fruit Battery

Our Group: Cheuk Sheung Kwan (2A) Ng Chu Him (2A) Tsang Wing Him (2B) Date: 21st July 2003 Venue: I.S. Laboratory, La Salle College

1.

Background of investigation

2. Research 3. Report of the experiment 4. Record of results 5. Conclusion 6. Reflection and self-evaluation

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MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

After the Industrial revolution, the world trade developed and the need of fine goods increase. The use of electricity also increase a lot to propel the machines and cars… If the supply of electricity is not stable, people had to find other ways to produce electricity. At 1800 A.D., an Italian Physicist called Alessandro Volta used a piece of cloth that with some dilute sulphuric acid and then put a slice of copper and zinc at each side to form the positive and negative terminal respectively. Nowadays, few people use fruit to produce electricity because the current is small, they are large in size and not convenience. In this experiment, we are going to find about the electricity that the fruit produce.

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MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

The concept of fruit battery There are citric acid and tartaric acid in the fruit. They are electrolyte. When the fruit is connected to copper and zinc, copper will become the positive terminal. This is because zinc has a higher ionisation than copper. Zinc will emit an electron in the dilute sulphuric acid, which further changes into ion. But, copper doesn’t have this process.

The arrangement of the metal with different 4

MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

ionisation Potassium (鉀) Calcium (鈣) Sodium (鈉) Magnesium (鎂) Aluminium (鋁) Zinc (鋅) 7. Chromium (鉻) 8. Iron (鐵) 9. Cadmium (鎘) 10.Cobalt 10.Cobalt (鈷) 11. Nickel (鎳) 12. Tin (錫) 13.Lead 13.Lead (鉛) 14.Hydrogen 14.Hydrogen (氫) 15.Copper 15.Copper (銅) 16. Mercury (水銀) 水銀) 17.Silver 17.Silver (銀) 18. Gold (金) The arrangement is according to the different ionisation from higher to lower. 1. 2. 3. 4. 5. 6.

Investigation question In the experiment, we are going to find out the voltage and ampere that the fruit produce and the difference between each kind of fruit.

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MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

Hypothesis Our prediction is that the more the fruit that connected in the circuit, the greater the voltage and ampere of the electric current. That is because in our last school year, we often came across the use of electricity.

Variables I.

The independent variables 1. The number of different fruit 2. The type of fruit

II.

The dependent variables 1. The electric current that the fruit produce 2. The light bulb will be light up or not

III. Variables that will be kept constant 1. The connecting wires 2. The cleanness of the knife which makes the wounds on the fruit 3. Type of the apparatus (e.g. voltmeter or computer) 4. Method of measuring results 5. The type of the positive and negative metal terminals 6. The size of the metal terminals

List of apparatus and materials Materials

Apparatus

5 oranges 1 pear 2 lemons 8 pieces of zinc 8 pieces of copper

1 voltmeter 1 ammeter 1 computer 1 data collector Connecting wires 20 metal clips 1 knife 6

MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

10 plastic holders

Procedure 1. Prepare the materials and apparatus listed. 2. Turn on the computer and connect the data collector to it. 3. Use a knife to make a wound on each side of the fruit. 4. Put a piece of zinc and copper on the wound respectively on the fruit. 5. Put the metal clips on the connecting wires and then use the clip to hold the terminal. 6. The two ends of the connecting wires should be connected to the positive terminal of one fruit to negative terminal of one another. 7. If you want to measure the size of the electric current, connect the fruit to an ammeter. But if you connect the fruit to a voltmeter, the voltage will be measured. 8. When the connecting of fruit and devices has been finished, record the result.

Amount of fruit 1 orange 2 oranges 3 oranges

The results 0.967 V 1.982 V 2.920 V 7

MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

4 oranges 5 oranges 1 pear 1 pear + 5 oranges 2 lemons + 1 pear + 5 oranges 1 lemon 2 lemons + 1 pear + 5 oranges

3.858 V 4.815 V 0.942 V 5.737 V 7.549 V 250 µA 240 µA

The voltage will be larger if there are more fruit. But the electric current did not rise as the number of fruit increase. For example, the voltage of 5 oranges is approximately 5 times than 8

MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

just one and the voltage of pear with 5 orange, they are nearly the sum of each measurement of them. But according to the result, the electric current of many fruit even not greater than a lemon. This tells us that the amount of fruit is not the main factor to determine whether the electric current is high or not. At the other hand, the number of fruit is the main reason that affects the voltage that they produce.

Cheuk Sheung Kwan: As I am the first time to do this kind of experiment and not greatly related to our school syllabus, I am very curious in that. I am wonder such fruit can be seen everywhere and they can be used as a power source. Connect some fruits together and the electricity was even greater than a dry cell, which surprised all of us. I am quite enjoying this experience and hope there will be more coming. Ng Chu Him: This is quite an interesting experiment. I haven’t even heard of using fruit to produce electricity. Despite my absence in the lab activity, I have tried hard to cooperate with my partners, and began brainstorming. I also have an enormous curiosity in why 1 lemon can “win” the other fruit by comparing electric current. I am looking forward to finding the solution and more relevant experiments for us to conduct. Tsang Wing Him: I like to do this project because it’s interesting. It’s amazing that fruit can be used to conduct electricity. Also, I can hardly think that the electric current of a lemon is even greater than 8 fruit together!!! 9

MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members

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MSA Investigation in Fruit battery Cheuk Sheung Kwan and his group members