Ohm's Law - Learning Undefeated

Ohm’s Law is an activity developed by Learning Undefeated to help students understand the relationship between voltage, current, and resistance.

In this activity, students will work to understand how devices like a three-speed fan or a dimmer switch adjust the flow of electricity in a circuit to have different outputs. Students will collect voltage and current data using two multimeters and graph their data. Student groups will be using a variety of resistors and will compare their data at the end to see if the resistance affected the voltage or current.

This activity is adapted from Carolina’s Ohm’s Law and Kirchhoff’s Rules kit.

Learning Objectives

Standards Alignments + Connections

Next Generation Science Standards Connections

HS-PS3-2.
Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motion of particles (objects) and energy associated with the relative positions of particles (objects).

HS-PS3-3.
Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy.

Virginia Science Standards of Learning Connections

PS.5B. Energy is transferred and transformed

PS.5C. Energy can be transformed to meet societal needs

PS.9C. Electric circuits transfer energy

PH.8A. Circuit components have different functions within the system

PH.8B. Ohm’s law relates voltage, current, and resistance

PH.8E. Electrical circuits have everyday applications

Activity Components

Pre-Laboratory Engagement

Human Circuit Demonstration

Present the energy stick to the class and hold one end of the stick in one hand. Then take your other hand and grab the other end of the stick. The energy stick will turn “on” demonstrating a circuit has been completed. You can extend the demonstration by requesting a volunteer. You and the volunteer will each hold one end of the stick, it will be “off”. If you and the volunteer touch hands, the energy stick will turn “on”. Lastly, take an alligator clip in one hand and have the volunteer hold the other end. Hold the metal part of the alligator clip, but the volunteer will not. You can then ask the students, “Why nothing is happening?” The volunteer will then grab the metal part of the alligator clip. The energy stick will then turn “on”.

Circuit Construction Kit PhET Simulation

Using their tablets/laptops students should open up the simulation. You will also open a simulation so that the students can see your screen. You should model for students how to pull down a battery and light bulb. Ask students how they would turn on the light bulb. Based on the answers given, the students will complete their instructions to see if their answers are correct. Once the successful solution is done, have students reset their simulation by hitting the reset button on the bottom right of the screen. In the simulation, place one battery and three lightbulbs and ask students to turn on all three bulbs. Monitor and check on student solutions. As students work on a solution, the teacher will set up an additional battery and three light bulbs and emphasize that there are two ways to solve this problem. Students are free to talk and work with each other at their station to find a solution. Students can turn the bulbs on through series or parallel circuits. Demonstrate both types of solutions on the screen(s). A parallel circuit shows the wires going from the battery to the light bulb for each light bulb.

Activity

What if there were no circuits? How would you play your favorite gaming systems, use your cell phone, or turn the on the heat on a winter day? The answer is simple, you would not be able to. All of these electrical devices rely on circuits.

Circuits are the foundation of modern electrical systems, powering everything from household appliances to complex machines. A circuit is essentially a closed loop that allows electricity to flow, enabling various devices to operate. Understanding the basic components of a circuit—such as current, voltage, and resistance—is essential for grasping how electrical systems function.

Current (I) is defined as which is the rate at which a charge moves through a circuit and is measured in amperes (a)

Voltage (V) is defined as the measure of potential energy and is measured in volts (V)

Resistance (R) is defined as which is a measure of an object’s opposition to the flow of an electrical current and is measured in ohms (Ω)

Post-Laboratory Extension

Teach Engineering’s Ohm’s Law I

Students experiment to increase the intensity of a light bulb by testing batteries in series and parallel circuits. They learn about Ohm’s law, power, parallel and series circuits, and ways to measure voltage and current.

https://www.pbs.org/wgbh/nova/labs/lab/cyber/

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