DC Electronics Exploration - Day 1

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Objective

Students will explore the ways in which energy is transferred in simple DC circuits.

Big Idea

Energy in circuits moves from power sources (batteries, power outlet) to circuit elements (light bulbs) though the action of moving charges.

Overview of the week

This week my students are engaging in a three-part exploration of DC electronics that is self-paced. Here's a look at the circuit properties they are exploring and some thoughts about the rhythm of the week.

 

Students develop an intuitive understanding and induce the important rules of circuits through a series of explorations. We limit our study to voltage divider and current divider circuits while introducing the ideas of series and parallel resistor networks.

Warmup

25 minutes

Knowing that we will soon be talking about moving charges that have electric potential energy, I provide my students with a warmup problem that features these elements. It is a challenging warmup - perhaps a bit too much so - and I present it both in its most challenging form and in a more scaffolded version, as can be seen in the following description of the roll-out.

I ask my students to try the more challenging version for three minutes, encouraging them to discuss approaches with one another as they work the problem in their notebooks. If, after that time, they are stuck and want to try the scaffolded version, I first solicit thoughts from them about fruitful ideas they've had. Eventually, a student mentions energy and we focus our thoughts on the transformation of potential energy (at the start) to kinetic energy (in the middle) with a return to potential energy (at the end). This is the key to solving the problem and, armed with that insight, I reveal the scaffolded version of the problem for students to complete. I provide a few more minutes of time to work on the problem, then show a solution to the scaffolded version of the problem.

Explanation of Energy Assignment

10 minutes

Before proceeding with our work for the day, I describe a major assignment that I want my students to begin. I distribute the handout entitled Understanding Conservation of Energy and allow students a few minutes to read it over before I address any questions they may have. Students are asked to select an audience (elementary school children, adults, etc.) and create a mechanism (video, pamphlet, poster, etc.) by which they will demonstrate their understanding of the conservation of energy to that audience. They are given a little more than a week to complete their assignment.

I assign this work now to bring the conservation of energy into the forefront of our studies. It has been a central idea in nearly all of our work to date and will continue to play a vital role in future studies. As such, students should be able to draw upon any number of scenarios as potential backdrops to their project. This assignment provides students an opportunity to be creative, playful, and thoughtful

In the video below, I share some thoughts about some of the previous year's submissions. 

Instructions and Self-Guided Exploration of Electric Circuits

45 minutes

Over the course of the next few lessons, students will engage in a self-guided, self-paced exploration of simple DC circuits.

We use a web-based simulator from ExploreLearning to pursue these goals. After a warmup section, students collect data and build their knowledge base on three important foundations of DC electronics; Ohm's Law, Voltage Divider circuits, and Current Splitter circuits. Students follow a set of instructions that I have previously downloaded and modified to suit my needs. I spend ten minutes describing their task and showing both the simulator and the instructions before asking them to self-select their work mode (individual, paired or tripled) for the day. Student then access the website and the document and begin the exercises. 

My modifications to the downloaded document turn the activity into a more data-centric activity than it was originally. For each of the primary sections, I have included data tables and prompts to arrange and analyze the data. By doing so, my students have additional opportunities to engage in the Eight Science & Engineering Practices of the NGSS, particularly Analyzing and Interpreting Data and Using Mathematics and Computational Thinking.

In terms of assessment, this is very much an "assessment for learning" strategy. I want students to be actively learning these electronics basics and using the simulation is a better vehicle for that goal than, say, a lecture. When we do pause to discuss ideas as a group and consolidate learning, students attend to those moments with more insight and interest as a result of this participation.

While students are working, I circulate and address issues that arise. This affords me an opportunity to provide direct, timely, and precise feedback about the concepts. Wherever students are at the end of this lesson, they save their work and continue in the next lesson.