The Arizona STEM Acceleration Project
Deriving Rules for Circuits in Series
Deriving Rules for
Circuits in Series
A 9-12 Grade STEM Lesson
Robert Woodruff
(adapted from lesson plan by Dave Tessmer)
January 2024
Notes for Teachers
This lesson is designed for students to derive the rules for circuits in series by experimenting with different variables in simple circuits in series using the PhET DC Electricity simulation lab.
List of Materials
Standards
High School Engineering:
STANDARD 4.0 APPLY SCIENTIFIC LAWS AND PRINCIPLES RELEVANT TO ENGINEERING TECHNOLOGY
4.1 Use the relationship among energy, work, and power to solve a variety of problems involving mechanical, fluid, electrical, and thermal systems
4.4 Analyze relevant properties of materials used in engineering projects [i.e., chemical, environmental, mechanical (tension, compression, torque), electrical, physical, etc.]
High School Physics:
Essential HS.P4U1.8
Engage in argument from evidence that the net change of energy in a system is always equal to the total energy exchanged between the system and the surroundings.
Plus HS+Phy.P4U1.8
Use mathematics and computational
thinking to explain the relationships
between power, current, voltage, and
resistance.
Mathematical Practices:
MP.4 Model with mathematics.
MP.5 Use appropriate tools strategically.
MP.6 Attend to precision.
Objectives:
Students will use the DC Electricity PhET lab to derive the rules calculating voltage, current, and resistance for circuits in series.
Students will be able to describe how to use the rules for circuits in series to calculate voltage, current, and resistance for circuits in series.
Agenda
55 Minute Lab:
0-5 Minutes: Teacher starts with the opener. Students read the lesson objective and open the DC PhET electricity laboratory. Teacher demonstrates how to make the simple circuit with light bulbs in series and how to use the ammeter and voltmeter to collect data.
6-49 minutes: Students use the lesson handout to gather data on voltage, current and resistance in series circuits. Students need to show their work. If teacher wants to, the students could put screenshots into their handout.
50-55 minutes: Class discussion on the opening question, “Why do the light bulbs get dimmer when put into a series circuit?”
Class discussion about how Ohm’s law was derived how to describe it both as a formula and in writing (question 12 and conclusion).
Intro/Driving Question/Opening
Let’s look at 2 simple circuits in this PhET simulation.
Why do the light bulbs get dimmer when we add a 2nd light bulb to the circuit?
Hands-on Activity Instructions
Assessment
Use the student handout for assessment and ask the following questions as an exit ticket:
In your own words, what are the rules for finding voltage, amperage (current), and resistance in series circuits?
What are the formulas used to calculate voltage, amperage (current), and resistance in series circuits?
Differentiation
Students can collect less data in the lab; complete only the first (or first two) data collection tables.
Student handout can be modified to include some of the values inside the data tables.
Provide key vocabulary and concepts with images.
Remediation
Extension/Enrichment
Have students use breadboards and LED lights (and resistors) to test the rules derived in this lab.
Additional Resources: