Fruit and Veg Batteries

This week we decided to see if we could get electricity out of fruit and veg. We used: a voltmeter a tomato a lemon a bit of play dough an old battery

First we carefully cut open an old zinc-carbon cell and peeled off a few strips of the zinc casing.  Then we used the back of a knife to scrape the zinc strip until it was clean and shiny.

We touched the two probes of the voltmeter together and the meter showed zero.  Then we stuck a piece of copper wire into one side of the bit of play dough and the zinc strip into the other side of the play dough, and then measured the voltage. Still zero!

Next we tried a tomato.  With the zinc strip in one side of a small tomato, and the copper wire in the other side, the voltage between the electrodes was 0.78 volts.  After the tomato, we tried a lemon.  This gave us 0.85 volts.

The last thing we tried was to make a battery by connecting a tomato and a lemon in series.  We took a strip of zinc and folded it around a bit of copper wire.  The zinc side went into the lemon and the copper wire into the tomato.  Another bit of wire went into the lemon and a second strip of zinc went into the tomato.  This gave us a voltage of 1.7 volts!

Next time we will try to light up an LED.

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View all the pictures on here.