With the help of a crocodile wire, connect the red terminal of the voltmeter with one of the two copper electrodes. In the same way, connect the black terminal (COM) of the voltmeter to the negative terminal of the battery with the second crocodile ended wire.
Now using the third wire with crocodile extremity, connect the positive terminal of the battery with the other copper plate. This completes the wire connection for the experiment.
Inserting Copper Electrodes
After that, fill the glass with distilled water and then immerse the two copper electrodes in it without letting them come in contact with each other. It will be observed that there will be negligible deflection shown in the voltmeter.
Removing Copper Electrodes
Remove the copper electrodes from the glass and add some salt in to the water. Stir thoroughly with the help of tea spoon to let the salt dissolved properly.
Placing Copper Electrodes in Salted Water
Now again immerse the copper electrodes in the salt solution. It will be noticed that some deflection is shown in the voltmeter showing that addition of salt ionizes pure water and allows conduction of electric current.