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For this project, Mia and I needed to build a house with 4 rooms and 4 circuits, 1 circuit per room. Each circuit would have lights that would light up its respective room. We had to build the following circuits: a parallel circuit, a series circuit, a combination circuit, and a circuit of our choice. This project called for a lot of critical thinking considering the amount of problems that were faced, which brought much frustration and joy.

Solution Fluency

DEFINE: In the beginning, we didn’t really know what we could print. We hadn’t really found any big problem that would perfectly be solved with 3D printing. But as we built and tested our circuits, we felt that holding both the battery and the wires while trying to fit the copper into the battery holes was getting pretty annoying.

DREAM: We only really thought of one good solution to this problem: a battery holder. At first, we thought about just making a box for the battery, but then I thought about it some more and realized that it wouldn’t really do or solve much. It would just be a case around the battery, almost just like an extension of sorts. So, we decided to add 2 rings onto the box that would hold the wires in place, in front of where the battery holes would be. But printing it didn’t work out at all due to how small the pieces were, as we had to try and print the pieces separately.

DELIVER: So, Mia and I decided to make a battery holder that would hold the wires in place by inserting the wires into the slits in front of the battery holes. That way, everything is in one big piece that would be more suitable for the 3D printer. Here is our final design:

DEBRIEF: The battery holder printed perfectly, but both the battery case and the wire slots could’ve definitely been a few millimetres tighter. The battery case wasn’t too bad—we were planning on holding the battery in place ourselves anyway—but the wire holders were too big to work smoothly. They still kind of helped in keeping the wires in the battery holes, but it was quite finicky.

Project Questions

1. You have 3 light bulbs. All have the same intensity when lit. Explain how you can prove to a classmate that they are connected in series by unscrewing one light bulb. Support your answer.

In a series circuit, if you unscrew one light bulb, the other 2 bulbs would turn off. This is because in a series circuit, there is only 1 pathway for electrons to flow through. If that pathway is severed, the circuit will not work at all (none of the bulbs would work)

2. You have 3 light bulbs. All have the same intensity when lit. Explain how you can prove to a classmate that they are connected in parallel by unscrewing one light bulb.

In a parallel circuit, if you unscrew 1 bulb, the other 2 would stay on. This is because in a parallel circuit, there are multiple pathways and each load has its own pathway. These pathways are not dependant on each other, so if you unscrew a bulb, the other bulbs will work perfectly fine.

3. You have three light bulbs. Two are connected in parallel. This is parallel combination is connected in series with the third light bulb. This parallel combination is connected in series with the third light bulb. Describe the relative intensity of each bulb. Support your answer.

The bulbs in parallel are the same in brightness, but dimmer than the bulb in series. This is because all voltage and current flows through the bulb in series before they reach the bulbs in parallel, which results in the bulbs in parallel to get half the amount of voltage and current (6V & 0.6A –> 3V & 0.3A)

4. In Question 3, describe the relative intensities of the two remaining lit bulb if one of the bulbs in the parallel was unscrewed. Support your answer.

If a bulb in parallel was unscrewed, both bulbs are the same in voltage, and current is the same throughout the circuit. This is because the circuit has now become a series circuit, where the total voltage is halved among the two bulbs, and current stays the same (VT = V1 + V2, IT = I1 = I2)

5. Outline a step-by-step method that could be used to determine the resistance of the light bulbs in one of your circuits. Feel free to include a circuit diagram of your set-up.

The following steps are for a series circuit.

1. 1. Find the voltage by connecting a voltmeter from both sides of the bulb.
   2. Find the current in the bulb by connecting an ammeter into the circuit.
   3. Using Ohm’s Law (V = IR), find the resistance by dividing the voltage by the current.

6. Using your method outlined in Question 5, determine the resistance of the bulbs in one of your circuits.

After following the instructions I wrote in Question 5, I found that my bulbs in my series circuit have a resistance of 7.6Ω

Core Competencies Reflection