Students discover circuit principles hands-on: lighting bulbs, building series/parallel circuits, measuring current & voltage, and creating I-V graphs for nonlinear resistors.
This three-week introductory physics lab sequence guides students through DC circuit concepts using an inquiry-based, constructivist approach. In Week 1, students explore arrangements of a battery, bulb, and wire to discover the conditions for lighting a bulb, then learn circuit diagram conventions and build series and parallel circuits. In Week 2, they deepen their understanding by comparing bulb brightness to infer current behavior, learn to use multimeters as ammeters and voltmeters, and develop qualitative models for current conservation, resistance, and voltage in series and parallel configurations. In Week 3, students design and conduct their own quantitative investigation of the current-voltage relationship for a light bulb (and optionally other elements), producing a detailed scientific graph. Throughout, students work collaboratively in teams with assigned roles, practice identifying and reducing sources of uncertainty (precision, statistical, and systematic), and build arguments from observational evidence rather than receiving direct instruction. Materials include student handouts, instructor facilitation guides with pacing and rubrics, sample slides, and homework assignments using the PhET Circuit Construction Kit.
By the end of session 1:
Share experimentation responsibilities with other group members
Document lab activities completely in organized lab notes
Predict arrangements of a battery, bulb, and wire in which the bulb will light or not light
Draw circuit diagrams for circuits with a battery and one or two bulbs
Build one- and two-bulb circuits
Logically analyze circuits to find and correct problems
Infer the presence and strength of current based on observable evidence of bulb brightness
By the end of session 2:
Draw circuit diagrams for circuits with a battery and one or two bulbs
Build one- and two-bulb circuits
Logically analyze circuits to find and correct problems
Infer the presence and strength of current based on observable evidence of bulb brightness
Predict and measure the amount of current through different parts of series and parallel bulb circuits
Explain voltage as the quantity of push (that pushes current in a circuit); predict and measure the voltage across different parts of series and parallel bulb circuits
By the end of session 3:
Measure current and voltage with a multimeter
Logically analyze circuits to find and correct problems
Decide how to measure data, including (1) how much data to collect (including number of trials, range of each variable, frequency/spacing of data collection) and (2) how best to reduce sources of uncertainty, systematics, or mistakes
Create a detailed scientific graph showing how current varies with voltage, for a small light bulb and some other circuit elements.
Experimentation Goals
These experimentation goals are most strongly represented in the explicit learning goals described above:
Student Decision Making
In this lab, students have the opportunity to:
Discovery
Determine results previously known to:
Duration
3 sessions of 2 hours/session
Equipment Required
Implementation Tips
Resist the urge to teach. The first activity — lighting a bulb with only a battery, bulb, and single wire — is designed for students to discover the requirements for a complete circuit through exploration. Don't tell them how; ask "What arrangements have you tried?" and "What else could you try?" They will find it, and the discovery is powerful.
Pacing is the main challenge. In Lab 1, students must reach circuit diagrams to stay on track; series/parallel can slide to Lab 2 if needed. In Lab 2, they must at least complete ammeter measurements; voltage can carry into Lab 3. Post a suggested schedule on the board each session.
For Lab 3, warn students to turn down the power supply if their bulb gets very bright — bulbs blow out easily. Have spare bulbs on hand.
The PhET Circuit Construction Kit DC (phet.colorado.edu) is used for homework and makeup assignments. For Lab 3 homework, use the "Lab" page with "Advanced" and "Add real bulbs" enabled so that simulated bulbs behave nonlinearly like physical ones.
A Desmos graphing template is provided for I-V curves and supports uncertainty bars and multiple trendline options. Students can also use Excel or another tool of their choice.
Strongly encourage students who miss Labs 1 or 2 to attend another section rather than doing a makeup, as hands-on circuit building is very difficult to replicate remotely. Lab 3 can be made up using another team's data to create the graph.
Have students use different font colors in their shared Google Doc so individual contributions are visible — this matters for grading the team agreement and assessing equitable participation.
How This Fits in Your Course
This is the opening unit (Labs 1–3) of a 9-lab introductory physics lab sequence for introductory electricity and magnetism. No prior physics lab experience or circuits knowledge is assumed — students build concepts from scratch through observation.
The sequence is deliberately front-loaded with structured inquiry so that students develop foundational lab skills (team collaboration, lab notebooks, circuit building, multimeter use, uncertainty analysis, and scientific graphing) that they will need for the rest of the course. By the end of Lab 3, students should be comfortable building circuits, using measurement tools, and creating scientific graphs, including uncertainty.
The circuits unit is followed by Lab 4 (Electrostatics), Labs 5–6 (Magnets), and Labs 7–8 (student-designed investigations), culminating in Lab 9 (presentations). The skills developed here — particularly experimental design, uncertainty quantification, and graphing — are prerequisite for the open-ended investigation later in the quarter, where students choose their own research questions and design their own experiments.
Sp26 Lab 1 Circuits - Instructor.docx
Instructor Supplement602 KBSession 1 Instructor Doc
Sp26 Lab 2 Circuits - Instructor.docx
Instructor Supplement219 KBSession 2 Instructor Doc
Sp26 Lab 3 Circuits - Instructor.docx
Instructor Supplement261 KBSession 3 Instructor Doc
Motor analysis handout.docx
Instructor Supplement4.5 MBSupplement to troubleshoot building and understanding motors.
Motor analysis handout.pdf
Instructor Supplement328 KBSupplement to troubleshoot building and understanding motors.
2026-02 (Sp) Lab schedule.docx
Other12 KBLab schedule for the entire course.
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Rachel Scherr
Lauren Bauman
Adrian Madsen
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