The Arizona STEM Acceleration Project
Deriving Ohm’s Law
Deriving Ohm’s Law
A 9-12 Grade STEM Lesson
Robert Woodruff (adapted from lesson plan by Dave Tessmer)
1-23-2024
Notes for Teachers
This lesson is designed for students to derive Ohm’s Law by experimenting with different variables in a simple circuit 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.
Objective(s):
Students will use the DC Electricity pHet lab to derive Ohm’s law.
Students will be able to describe Ohm’s law with a formula and through written expression.
Agenda (lesson time)
55 Minute Lab:
0-5 Minutes: Teacher start with the opener. Students read the lesson objective and open the DC pHet electricity laboratory. Teacher demonstrates how to make the simple circuit and how to use the ammeter and voltmeter to collect data.
6-20 minutes: Students use the lesson handout to gather data on voltage, current and resistance (questions 1-3 on handout).
21-30 minutes: Teacher helps/monitors students graphing the data, inserting graph into the student handout and calculating the slope of the line in the graph (questions 4-8).
31- 50 minutes: Students continue to gather data using the student handout and derive Ohm’s law (questions 9-12)
50-55 minutes: 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
What is an electrician?
What do electricians do?
How much money can an electrician make in Arizona?
Low - $53,000 Median - $69,000 High - $ 86,000
One of the things electricians do all the time is work with voltage, resistance, and current. Today, we will explore how these concepts are related!
Hands-on Activity Instructions
Assessment
In your own words, describe how are voltage, current, and resistance related.
What is the formula that describes the relationship between voltage, current, and resistance?
Differentiation
Students can collect less data points for question #2 in the student handout.
Students can be given a graph of the relationship between voltage and current (with constant resistance).
Students can be given a handout with the graph completed and with slope calculated.
Remediation
Extension/Enrichment
Describe major milestones in the life of Georg Ohm.
Describe major milestones in the work of Georg Ohm.
Describe how Georg Ohm derived Ohm’s law.
Additional Resources: