Students build magnetism concepts hands-on, practice scientific integrity through the Millikan case study, and learn to critique and craft research questions for independent investigation.
This two-week introductory physics lab sequence guides students through magnetism concepts while weaving in scientific integrity practices and research-question development. In Week 1, students identify magnetic poles, use compasses to map magnetic field direction and relative strength, represent fields with vectors, and demonstrate superposition by comparing a bar magnet to a stack of smaller magnets. They also discuss the Millikan electron-charge story as a case study in experimental bias and commit to specific strategies for reducing bias in their own work. In Week 2, students measure the magnetic field of a current-carrying coil as a function of current, create scientific graphs with uncertainties, and analyze how a simple DC motor operates. They also critique sample research questions against explicit criteria (answerable, experimental, feasible, focused, generalizable) in preparation for designing their own independent investigation later in the quarter. Throughout both weeks, students work in assigned teams with defined roles and practice giving brief presentations of their findings.
Learning Goals for Session 1:
Identify magnetic poles on a permanent magnet and distinguish the two types of poles
Use a compass to measure the direction and (qualitative) strength of a magnetic field
Represent magnetic fields with vectors and field lines
Demonstrate the principle of superposition for magnetic fields, e.g., a bar magnet is equivalent to a stack of short magnets
Describe and carry out multiple practical, actionable, and creative strategies for mitigating bias during experiments
Learning Goals for Session 2:
Critique proposed research questions in terms of given criteria
Decide how to measure magnetic fields, 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 magnetic field varies with distance and current
Describe and carry out multiple practical, actionable, and creative strategies for mitigating bias during experiments
Analyze the operation of a simple motor, including how the coil interacts with the magnet to keep the coil spinning
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
2 sessions of 2 hours/session
Equipment Required
Implementation Tips
Students should complete Parts I–III of Lab 5 (poles, fields, superposition); Part IV (quantitative measurement) is a stretch goal and can be skipped without loss. In Lab 6, prioritize Part I (coil magnetic field vs. current) and Part II (motor analysis); Part III is again optional time-permitting work.
Watch for students disassembling the motor kit in Lab 6 — they sometimes confuse the motor's internal coil with the separate measurement coil. Including a photo of the intended coil in the handout helps.
For magnetic field measurement, students choose between a Logger Pro sensor and a phone app (Physics Toolbox or Phyphox). Let them try both briefly before committing. Remind them to locate the magnetometer sensor in their phone and to use weak magnets when first orienting with the app.
The Millikan scientific integrity discussion in Lab 5 works best as a brief instructor-led conversation (~10 min) rather than a lecture. Frame it around the idea that even excellent scientists need community strategies to protect objectivity, then have students write their own concrete bias-mitigation plans.
For Lab 6's research question critique, display sample questions and have the class evaluate them against the five criteria before students revise their own. Providing both good and flawed examples is more effective than abstract discussion of criteria.
A Desmos graphing template with uncertainty bars and multi-option trendlines is available and works well for students unfamiliar with graphing software
How This Fits in Your Course
This two-week sequence falls in weeks 5–6 of a 10-week introductory algebra-based physics lab course (BPHYS 118/122) focused on electricity and magnetism. Students should have prior experience with circuits (Labs 1–3) and electrostatics (Lab 4), giving them familiarity with electric charges and fields so they can compare and contrast with magnetic phenomena. Students should also have practiced basic measurement techniques and uncertainty estimation in earlier labs.
The sequence serves a pivotal transitional role in the course. It introduces the final major physics content (magnetism and motors) while simultaneously preparing students for the independent investigation that occupies the remaining weeks. Lab 5 introduces scientific integrity practices that students carry forward, and Lab 6's research question critique directly feeds into students proposing and refining their own research questions for Labs 7–8, culminating in a final presentation in Lab 9.
2026-02 (Sp) Lab schedule.docx
Instructor Supplement12 KBLab schedule for the entire course.
Sign in to join the discussion.
Rachel Scherr
Lauren Bauman
Adrian Madsen
CC BY-NC-SA
Attribution, Non-Commercial, Share Alike. Others can share and adapt for non-commercial purposes, must attribute and share with the same license.
