Fox Williams teaches electrical theory and trades math to women pursuing careers in construction. Like many instructors of introductory level mathematics courses, she looks for ways to make clear connections between mathematical ideas and real-life applications. From small electronics to transmission lines, Ohm’s law explains the phenomena of how we use electricity. Ohm’s law is the foundation of electrical theory and is based on linear equations and proportional reasoning.
This active learning sequence utilizes a free online graphing calculator to determine linear relationships in Ohm’s law. The assignment allows students to plug in given data and based off their observations, determine how voltage and current relate to each other in a circuit.
Digital Resources
Desmos
https://www.desmos.com/calculator
Desmos is an online graphing calculator, which is available free of cost. Students can access Desmos from a wide variety of devices and complete the assignment synchronously or asynchronously. Williams recommends using a school’s LMS and other free resources that are accessible via smartphone or laptop whenever possible.
Digital Enablement
For this particular activity, Williams wants students to connect the algebraic concept of slope to the relationship between current and voltage. By using Desmos, students can avoid the tedium that sometimes accompanies graphing points by hand, and more quickly see patterns and relationships between voltage and current. Williams concludes the activity with a sentence frame that guides students to the conclusion that “when the voltage across the resistor increases, the current through it increases.”