Building Series Circuits
Lesson 4 of 14
Objective: SWBAT wire a circuit with more that one bulb in a series, and demonstrate knowledge of electricity flow by describing what happens when a bulb is removed.
I started off by having them write the focus question, "What are the characteristics of a series circuit?," in their science notebooks. I then had them explain to someone at their table what the characteristics of a circuit are. This reinforces the learning for students that remember, and reminds students that have already forgotten. I then explain their challenge is to light up two bulbs using only one battery, 3 wires, and two bulbs in holders. I also let them use tape to hold the wires to the batteries.
I reminded them of expectations for group work, and called one student from each table to get materials for each group. As they were building, I helped them troubleshoot by using the vocabulary of the unit, such as "You have the bulb holder connected to the insulation on the wire," instead of "the plastic part."
Once they were able to light up two bulbs, I asked them to respond to these questions, which I wrote on the board.
- What happens to the other bulb when you unscrew one light bulb?
- What happens to the amount of light when more bulbs are added? Why?
I offer them an additional bulb and wire to test their ideas. I chose these questions to build students' conceptual understanding that the energy within the circuit is finite; the amount of electricity flowing doesn't change, so as the energy is divided, the bulbs do not glow as brightly. The second question helps them see the difference between a parallel and series circuit, which in turn helps them to understand how electricity flows through a circuit, how it must make a make a closed path, and that electricity will follow the path of least resistance.
After most students are complete, I collect a sample of notebooks for ongoing formative assessment.