Testing the effect of electric current on potato in Electrical Conductivity of Liquids – Class 8 Science Experiment
Chapter Name: Electrical Conductivity of Liquids
Activity Name: Testing the effect of electric current on potato in Electrical Conductivity of Liquids
Activity Description:
In this experiment, we will investigate the electrical conductivity of a potato by passing electric current through it using a simple tester with an LED bulb.
By inserting two copper wires into the potato and connecting them to the positive and negative terminals of a battery, we will observe the effect of the electric current on the potato over a period of 20-30 minutes.
Required Items:
- Potato
- Knife for cutting
- Tester with LED bulb
- Two copper wires
- Battery (with positive and negative terminals)
Step by Step Procedure:
- Take a potato and cut it into two halves.
- Choose one half of the potato for the experiment.
- Construct the tester by inserting the two copper wires into the potato, leaving some distance (about 1 cm) between them. One wire should be connected to the positive terminal of the battery, and the other wire to the negative terminal.
- Assemble the tester with the LED bulb.
- Check if the LED glows when the circuit is connected.
- Leave the inserted wires in the potato for 20-30 minutes.
Experiment Observations:
- The LED bulb should glow when the circuit is connected, indicating that the potato allows the passage of electric current.
- After leaving the wires in the potato for some time, a greenish-blue spot will be observed on the surface of the potato around the wire connected to the positive terminal of the battery. However, no such spot will be seen around the other wire connected to the negative terminal.
Precautions:
- Take necessary precautions while handling the knife and the battery to avoid any accidents or injuries.
- Ensure that the copper wires are properly inserted into the potato to establish good electrical contact.
- Do not touch the wires or the potato while the current is passing through them to prevent electric shock.
Lesson Learnt from Experiment:
The greenish-blue spot observed on the potato around the wire connected to the positive terminal of the battery indicates a chemical change within the potato due to the passage of electric current. This phenomenon demonstrates that the potato has some electrical conductivity, allowing ions or electrons to move through it.
