Simon wrote a poster with electricity formulas (from memory) this morning and applied one of them (Ohm’s law) to his advanced lemon experiment.

We had already tried this experiment before but one lemon did not light an LED. Simon’s become more of an expert this time around. He used not one but 4 lemons now and measured the voltage (in Volts) and the current (in Amperes).

And he employed his sister as assistant.

The four lemons gave us almost 4 Volts!

Simon used his voltage and current measurements to determine the resistance:

He then decided that 24 Ohms was too little and added a resistor to his lemon circuit:

But with a resistor the LED light did not light up – apparently the voltage became too low. After all, the voltage is the resistance times the current. I suggested Simon try it again without the resistor, with the almost 4 Volts the lemons made. And it worked!