Conceptual Physics Squishy Circuits Lab
To be completed in your lab notebook
Pre Lab:
· On a fresh piece of paper in your lab notebook write today’s date and the title of the lab.
· Don’t forget to continue the page numbers in your lab notebook.
· Don’t forget to add this lab and its page number to your Table of Contents.
1. Define Series circuit.
2. Define Parallel circuit.
3. Define Current.
Procedure:
Electricity has to flow through something that is conductive and will not flow easily through something that is not a conductor but an insulator. The special play dough is electrically conductive and will act like a wire.
?Underneath your Pre-Lab, write “Observations” and you will answer the questions below in complete sentences. Follow the instructions below and answer the Observation Questions that are marked with bullet points as you go along.
1. Roll your play dough into a rope like at right. This rope will act as our wires. Electricity will flow through the “wires” back to the battery using the path of least resistance.
2. If you want the electricity to pass through a light bulb you will need to create a break in the dough or the electricity will pass through the dough instead of the light bulb. Light Emitting Diodes or LEDs are directional and will only work if oriented the right way. Before you put your LEDs in the dough check the direction with your battery.
3. Try adding more lights in series which means there is only one path from one terminal of the battery back to the other. Make a large circle with your dough and cut it into four pieces so that there are four gaps in the dough like below. Attach a battery at one gap and a light across the other three. Be sure that the dough does not touch each other and that the lights are in the right direction.
· What do you notice about the brightness of the bulbs when they are in series?
4. Now create two parallel ropes of dough and attach the battery to one side. Connect several lights as if they were the parallel rungs of a ladder along these two parallel pieces of dough. These lights are now in parallel and the electricity could go through any of the bulbs creating different paths.
· What do you notice about the brightness of the bulbs when they are in parallel?
· How does the brightness of these bulbs in parallel compare to the brightness of the bulbs in your last experiment in series?
5. Now create three blobs of clay and connect each side of the battery to one blob. Connect three lights between the blobs so that they are all connected as in the picture at right.
· What do you notice about the brightness of the bulbs? Which bulb is brightest?
· Which bulbs appear to have the same brightness?
· Why do you think this is the case?
Applying:
?Underneath your Observations, write “Applying” and you will answer create each of these circuits through trials and error. Don’t forget to number your answers! Clearly sketch your circuit using the examples above that shows how you successfully created each.
1. Create a circuit in which you use four lights total and all four have the same brightness.
2. Create a circuit with four lights total in which three have the same brightness and are dimmer than the fourth.
3. Create a circuit with two bulbs in series that is parallel to two more bulbs in series.
Based on what you learned in this lab answer these questions in complete sentences:
4. What two factors affects a light bulb’s brightness?
5. Do you think using a smaller voltage battery like a AA would affect the brightness of the light bulbs? Why or not?
6. DO NOT DO THIS, but hypothetically if you were to stick a blob of the dough onto the two terminals of the battery what would happen to the battery and why?