Voltaic cells are based on electrochemical reaction. The reaction
typically occurs between two pieces of metal, called electrodes, and
a liquid or paste, called an electrolyte.
Many fruits and liquids can be used for the acidic electrolyte.
Copper and Zinc plates are used as electrodes.
Instructions
Make a lemon cell and connect as shown in the figure, measure the
voltage at A1.
Connect the 1K resistor and measure the voltage again. The voltage
drops because of the internal resistance of the cell.
