The electric current comes from the chemical reaction between the acid in the lemon and the zinc. Positively charged hydrogen in …show more content…
Keep in mind that one or even several lemons in series produce only a tiny amount of voltage. The amount is unpredictable and dependent on many factors, including the acidity of the lemon and the metals used. One lemon should light a tiny bulb, but then again it may not. Try testing with a voltmeter. If the meter swings a tiny bit, you know that it is working. Wiring several lemons in series (bulb-copper-lemon-zinc-connecting wire-copper-lemon-zinc-bulb) may do the trick. If you can't get a light bulb to work, try improvising a galvanometer to show the voltage. Do this by wrapping about ten turns of thin wire (insulated) around a small magnetic compass to form a coil. Strip the free ends of the wire and touch them to the zinc and copper strips in the lemon. The current should be enough to set up a small magnetic field in the coil, causing the compass needle to