Circuits it one of my favorite units to teach. Many students enjoy the problem solving, straightforward calculations of series and parallel circuits and even more students enjoy the many, many labs of the unit. My approach centers around connecting all the lab experiences directly to the equations they are using, this unit is the best for that skill- taking apart an equation, explaining the graph showing the relationship, and determining meaning of slope and intercept. I start the unit with the “MIT Circuit Challenge”- passing the video to hand students the battery, wire, and bulb.
Project: Circuit Labs
Due to the numerous labs scheduled for this unit, I adopt a divide and conquer strategy when preparing for their review. Each lab is assigned to a specific lab group tasked with creating a concise one-pager and a video overview. This approach aids students in honing their focus during each lab session and alleviates the pressure of composing individual reports. I simply gather the circuit lab summary and individual lab handouts to track the students' progress, with the more comprehensive lab analysis being saved for the culminating project. The one-pagers and videos serve as valuable resources throughout the unit and prove to be effective tools for revision leading up to the AP Physics 2 examination.
In this introductory lecture, students will delve into the fundamental vocabulary and ways ammeters and voltmeters will be used throughout the unit. This lecture aims to prepare students with a solid vocabulary and understanding of the basics of circuit laws, laying the foundation for the upcoming unit labs. By familiarizing themselves with the terminology and tools integral to circuit analysis, students will be well-prepared to tackle the practical aspects of the rest of the unit. This lecture is very much breadth over depth, which I think sets up the unit well- the labs will provide the depth!
Resistor Labs
The first lab is probably the “biggest”- resistors in series and parallel. I encourage to have one student running on simulation while students are doing the hands-on lab in a group- helps with the conceptual application and discovery of series and parallel laws! Finding the properties and resistivity of playdough is always a fun one, and once students understand how to quickly check if resistance is constant, the “Is it ohmic” lab is great to divide and conquer!
Since student’s discovered the laws in the lab, this lecture is focused on the math of solving circuits- approach them like a puzzle!
Favorite Game: Crack that Circuit
PhysicsClassroom Concept Builders - My go-tos are Know Your Potential, Equivalent Resistance, and the Series and Parallel Calculation ones!
I love using the pHet Simulation during the lecture to introduce RC circuits for the visual; then do the lab.
Another small demonstration is the internal resistance of a battery; which I can never get good results for… but show the math of it anyways.