Series Circuit Investigation

Overview

In this seventh lesson of “Circuits, Current, and Creativity,” students build and analyze a series circuit using the uploaded “Series and Parallel” reference image as a visual model. They predict what will happen when one connection is open, test the prediction, and record evidence to explain how components in a series circuit are connected.

Learning intentions

Students will be able to:

• Identify the components and complete path in a series circuit.
• Predict how an open connection affects the other components.
• Build and safely test a low-voltage series circuit.
• Use observations and a simple circuit model to support an explanation.

Success criteria

• I can draw or identify one continuous path for current in a series circuit.
• I can predict what happens when one connection is opened.
• I can build a working series circuit safely and systematically.
• I can use evidence from my test to explain whether my prediction was correct.

Curriculum links

• Washington State K–12 Science Learning Standards: students develop and use models to represent how parts of a system interact.
• Common Core literacy in science and technical subjects: students follow a technical procedure, record observations, and describe the sequence of events in an investigation.
• Mathematical Practice: students model a real-world system with a labeled diagram and use evidence to reason about its behavior.
• The Number System: students connect changes in a system to positive, negative, or zero change in observable output where appropriate.

Lesson structure (40 minutes)

1. 0–5 min · Hook and prediction. Teacher displays the uploaded “Series and Parallel” reference image through the hook and reference-image slide and asks, “If one connection in this circuit is opened, which component will stop working?” Students silently predict, then share a claim and reason with a partner.

2. 5–11 min · Model the system. Teacher reviews the cell, wires, switch, and bulbs or LEDs, emphasizing that a series circuit has one continuous conducting path; teacher demonstrates how to open and close a switch without connecting a battery directly across itself. Students trace the path on the series circuit investigation sheet and identify where an open connection could occur.

3. 11–15 min · Procedure and safety check. Teacher uses the components, procedure, and safety slides to model the build sequence: connect the power source, add components one at a time, check the path, and test briefly. Students repeat the safety expectations: use only the supplied low-voltage equipment, keep connections secure, never use wall outlets, and disconnect the battery when finished.

4. 15–27 min · Build and test. Teacher assigns students to groups of three—builder, recorder, and checker—and circulates, asking, “Where is the complete path?” and “What evidence shows the circuit is closed?” Students build a series circuit, test that all components operate, then open one connection or switch and observe every component. They record the initial condition, the change made, and the resulting evidence on the prediction, test, and evidence table.

5. 27–34 min · Analyze and explain. Teacher pauses groups and displays the evidence discussion slides with the prompts, “What changed?” “What stayed the same?” and “Why did the other components respond?” Students compare observations, complete a labeled circuit diagram, and write a short CER response: claim about an open connection, evidence from the test, and reasoning based on the single-path model.

6. 34–40 min · Share and assess. Teacher invites two groups to share different evidence or troubleshooting steps, then displays the plenary and exit-ticket slide. Students complete the final worksheet question independently: draw a series circuit and explain what happens when one connection is open, using the words path, connection, and component.

Resources

• Low-voltage batteries or battery holders
• Insulated connecting wires with alligator clips
• Small bulbs in holders or low-voltage LEDs with suitable resistors
• Simple switches or foil/paperclip switches
• the series circuit investigation deck
• the series circuit investigation sheet
• Uploaded “Series and Parallel” reference image
• Safety goggles and component trays
• Optional the circuit symbol and component cards for quick component identification

Assessment

• During the hook, listen for predictions that connect an open connection with interruption of the complete path.
• During construction, check whether students can identify a closed path, use equipment safely, and record observations rather than guesses.
• Use the final diagram and explanation as an exit assessment. Look for an accurate series-circuit model, the prediction that all components stop operating, and evidence-based reasoning.

Differentiation

• Support students with a partially completed circuit diagram, a word bank—path, open, closed, connection, component, evidence—and the sentence frame: “When ___ is open, ___ because ___.”
• Pair students strategically and assign rotating roles so students can contribute through building, observing, recording, or explaining. Provide pre-sorted components and a teacher-built model for students who need reduced setup complexity.
• For EAL students, preview component names with the visual reference image and permit labeled drawings before written explanations.
• Challenge ready students to create two different open-connection tests, compare the results, and explain why adding another component in series may change the brightness or output.