ALEX Lesson Plan

Discovering and Applying Ohm's Law

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  This lesson provided by:  
Author:Robyn Lowe
System: Arab City
School: Arab High School
  General Lesson Information  
Lesson Plan ID: 35563


Discovering and Applying Ohm's Law


Students will design an experiment to relate the voltage difference and current in a circuit. They will collect data, then create and analyze a graph in order to arrive at Ohm's Law. They will create circuits and determine the voltage difference, current, and resistance in the circuit using Ohm's Law.

This lesson results from the ALEX Resource Gap Project.

 Associated Standards and Objectives 
Content Standard(s):
SC2015 (2015)
Grade: 9-12
12 ) Use the principles of Ohm's and Kirchhoff's laws to design, construct, and analyze combination circuits using typical components (e.g., resistors, capacitors, diodes, sources of power).

Local/National Standards:


Primary Learning Objective(s):

Students will discover and apply Ohm's law by analyzing data.

Students will use the principles of Ohm’s law to design and construct a circuit.

Additional Learning Objective(s):

 Preparation Information 

Total Duration:

91 to 120 Minutes

Materials and Resources:

Each group of 4 Students:
Computer with internet access and Logger Pro, DC variable power supply, connecting wire with alligator clips (set of 3), 1 resistor (10 Ω is recommended), 1 whiteboard, dry-erase markers, paper, pencil, handout "Ohm's Law Lab" (see attached document).

*Logger Pro is available for free to any Alabama Science in Motion trained teacher - see your specialist for details. Other graphing software such as Graphical Analysis or even Excel could be used, although Logger Pro is recommended.

Each student will need a copy of the Exit Ticket (see attached document). 

Each student will need a copy of the Ohm's Law Quiz (see attached document). An answer key is provided for the teacher. 

*Students needing acceleration will need a copy of the Extension Activity (see attached document) and one additional resistor. 

*Students requiring intervention will need access to this website:

The teacher will need copies of all attachments.

Technology Resources Needed:

Each group of 4 will need a computer with internet access and Logger Pro (or other graphing software as indicated above).


Before this activity, the teacher should introduce students to the:

  • definition of a circuit.
  • components of a circuit
  • open vs. closed circuit.
  • sketching a circuit.

Students should be familiar with the concept of circuits - essentially, components of circuits and definitions of the voltage difference, current, and resistance. Students should also know the equation of a line.


BEFORE: Have students sketch (on their own paper) a simple circuit with all three major components. Ask for three volunteers to draw their circuits on their whiteboard, show the class, and see if all students agree that what they have drawn is a complete circuit.

DURING: Pose the question - What is the relationship, if any, between the voltage difference and the current in a circuit?

Part I

Students should develop and carry out a procedure to measure voltage difference and current. They should keep one resistor in the circuit and change only the voltage difference or the current, then record the new data. It is at student/teacher discretion how many points of data to collect (6 is recommended). At the end of the experiment, they should have several points of data that include current and voltage difference for each point. 


A sample procedure can be found in the attachment "Sample Student Report".

Part II

After the students collect the data, they should graph using the Logger Pro software and do a 4-step analysis of the graph.

1) Write the equation of a line
2) Replace X and Y with the experimental variables.
3) Replace m and b with their values from the graph.
4) Write the final equation (the mathematical relationship). Determine the significance of the slope by looking at what was held constant in the equation.

Part III

Assign students the post-lab questions (see lab sheet) to practice using Ohm's Law, which they will have just discovered.

AFTER: Have students present their results by writing their findings on the whiteboard or interactive whiteboard. All groups should present their graph and 4-step analysis. Each group should also have an assigned question from the worksheet to present. Students should present their graph and explain how the graph led them to the discovery of Ohm's Law. They should also work through their assigned problem. Allow other groups to ask the presenting group questions.

**Some files will display in a new window. Others will prompt you to download.

Assessment Strategies

Teacher observation
Exit Ticket (Day 1 - Draw your data table. This lets the teacher know if the student has collected the appropriate data during the lab - essentially, it lets the teacher know if the first part of the lab was successful)

Whiteboarding (each student in the group must talk - this allows the teacher to informally assess individual students)
Lab Report
Quiz (see attachment "Ohm's Law Quiz")


Students seeking to expand their understanding of Ohm's Law and circuits can complete the activity in the attachment "Extension".


Students needing additional help can do the Glencoe virtual lab on Ohm's Law. Instructions and follow-up questions are provided on the website and can be done on the student's own paper.

View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.