Simple Circuits Curriculum

This lesson introduces a concept that is commonly used by scientists called "electrical potential." It builds upon what students typically learn about static electricity, imbalance, and net charge. It has a Relational Causal Model at the core. It complements the Cyclic Simultaneous Model, focusing on the system at a slightly higher level. The lesson assumes that students have learned about static electricity.

Section 8: Understanding Goals

Subject Matter

• In a circuit, electric charge flows from areas of greater charge to areas of lesser charge, just as it does in the build-up of static electricity.
• The role of the battery in a circuit is to maintain an imbalance in the concentration of electrons between opposite ends of the battery.
• Even though the circuit is "full" of electrons when the wires are first hooked up, the electrons and protons are balanced so there is no electrical charge along the wires. (The electrons are equally crowded or spaced out throughout.) It is the movement of imbalance along the wires that results in flow and lights the bulb.

Causality

• The concept of "electrical potential" introduces another casual model for thinking about what happens in a circuit. Electrical potential has an underlying Relational Causal Model. The cause of electrical flow has to do with balance and imbalance.
• Reasoning about electrical potential and the inherent Relational Causal Model complements a Cyclic Simultaneous Model. Even though they each have a different type of causality at the core, they work to explain electrical flow at different levels of focus within the system.
• The concept of electrical potential may appear superficially similar to the Cyclic Sequential Model if students don't grasp the differences at a deeper level. However, models that use the concept of electrical potential and an underlying Relational Causal Model necessitate that we attend to the whole system at once, not just a part of it.