Video for Reference: https://youtu.be/i4-9U2wkwD4
Time: 30 Minutes
Materials:
- 2 copper wires
- LED lights
- 9V Battery
- Store bought Play Dough
Equipment
Assemble circuit:
- You will connect the battery to your copper wire. First, make a small loop around one terminal of your battery with the copper wire.
- Put a piece of play dough on the other end of the copper wire.
- Wrap the other copper wire around the other terminal.
- Put another piece of play dough at the end of the second copper wire.
- Create any play dough shapes you want, but make sure there is a gap between the pieces.
Complete the circuit with LED lights:
- Put one end of the LED light into one piece of play dough, and put the other LED wire into the other piece of play dough.
- The electricity will have to flow through the LED light in order to complete the connection.
- Play dough acts as your resistor so you may have to push your LED light further into the play dough so the right amount of electricity passes through your light. (You may also have to pull the LED wires further out of the play dough if it only lights dimly.)
- You can control the amount of electricity going into the light by moving the LED around in the play dough.
- If your circuit still does not light, check the connection between the battery and the copper wire. Your LED lights will be bright if you give electricity a path to travel.
Shocking Fact: Why is play dough a good conductor of electricity? The amount of salt in the dough allows electrons to move freely within the dough! Salt is an ion that allows the flow of electrical charge.
Important note about resistance: The LED lights and playdough provide resistance in our circuit, therefore we do not need to buy a resistor separately. A resistor job is to limit the flow of electrons in a circuit, so the light bulb won’t become overpowered or burn out quickly. Also, the L.E.D. lights have a certain voltage of 3.2 volts, the battery is 9 volts, therefore, they have a pretty good amount of voltage difference. A resistor makes sure that the voltage difference has a very small impact on the current. Both LEDs and playdough have a built in resistance that allows the current to flow, despite the voltage difference.
After you conduct the experiment, watch my experiment to learn important vocabulary. After you watch my video, you can answer these questions: