**Physics First:** Electricity and Electrical Energy Units

Electricity is a natural phenomenon that can be both invisible AND visible, both matter and energy, a type of wave made of protons or a force that cannot be seen. It can move at the speed of light... yet it vibrates in a cord without flowing at all. It can be weightless, or have a small weight. Flowing in a light bulb filament, it transforms into light, but is not used up. It can be stored in batteries. "Electricity" is not only a class of phenomena; it's a type of event.

### A Model for Electricity (4)

#### Activities:

Don't dismiss this resource as too easy for high school. Although simple, this Flash tutorial packs a lot of punch. It goes beyond the commonly-used water flow/electricity analogy to explore what is really happening when electrons flow through a simple circuit. The authors carefully designed it to prevent misconceptions about electric current and prepare students to study electric field and potential.

A simulation that illustrates the "water-flow" model of electricity. The water pump represents a battery in a circuit; coiled water pipe represents a resistor. Students control the rate of flow through the pipe. *EDITOR'S NOTE: This model helps students understand some very basic ideas about current flow. We recommend using it with the resource directly above from "The Electricity Book".*

**Item Type:**Interactive Simulation

**Level:**Grades 6-12

This high-quality interactive simulation can be easily adapted for both middle school and high school. Students build a virtual DC circuit, using "click and drag" to attach wires, batteries, switches, and resistors. This particular simulation has received excellent reviews in extensive field testing, especially when done in conjunction with a hands-on lab.

**Item Type:**Interactive Simulation

**Level:**Grades 6-12

#### Content Support For Teachers:

It may be easier to understand about electricity if we think of electric charge as a sort of a fluid, like water, as scientists did for over 200 years. *NOTE: There are limitations to the fluid analogy. For more, see "The Electricity Book Part 2" under Activities above.*

### Electrical Charge (2)

#### Lesson Plans:

This item is a lesson plan featuring the neon bulb, an object that can be lighted either by electric current or by static electricity. Accompanied by detailed background information, this lesson promotes conceptual understanding of electron transfer.

**Item Type:**Lesson Plan

**Level:**Grades 6-10

**Duration:**One Class Period

#### References and Collections:

This collection of 50+ interactive java tutorials would be an excellent choice to connect physics to "real-world" applications. Designed by well-respected authors, the topics range from simulated magnetic fields and field lines to primers on capacitance, resistance, Ohm's Law, and electromagnetic induction. Included are simulations on how things work, such as vacuum tube diodes, cathode rays, capacitors, AC/DC generators, hard drives, pulsed magnets, and speakers.

### Moving Charges and Electric Circuits (12)

#### Lesson Plans:

If you like the PhET Circuit simulator (and who doesn't?) you'll appreciate this series of three inquiry-based activities developed especially to accompany the sim. Designed by PhET Gold-Star winner Trish Loeblein, the activities explore basic properties of electric circuits, resistors in series and parallel circuits, and more. Bonus: includes clicker questions.

Don't have time to do three lessons with the PhET Circuit Simulator? This lesson plan, specifically designed for use with the simulation, takes one day in computer lab and one follow-up day. We highly recommend it as a way to let your students explore circuits, learn from mistakes, and be better prepared to participate in the hands-on circuit lab.

This one-day lab is a great way for students to investigate factors causing short circuits. Reproducible prediction charts help students learn by gauging their preconceived ideas against observed outcomes in the lab. Materials are readily accessible and inexpensive to obtain.

This module asks students to apply knowledge of electric circuits in designing a system where one switch can turn on multiple lights. Students work in teams to predict the difference between the two circuit designs, and then build examples of the two systems using wires, bulbs, and batteries. *Editor's Note: We recommend teaming this lab with the PhET DC Circuit Simulator, found in "Activities" below.*

**Item Type:**Lab Activity

**Level:**Grades 5-9

**Duration:**Two Class Periods

#### Activities:

This high-quality interactive simulation is a good choice for beginning high school physics or physical science. Students build a virtual DC circuit, using the mouse to attach wires, batteries, switches, and resistors. This particular simulation has received excellent reviews in extensive field testing, especially when done in conjunction with a hands-on lab. *See Lesson Plans** above for a recommended lesson developed specifically for use with this simulation.*

For the novice with little prior experience in circuit construction, this item offers well-organized step-by-step directions for setting up series and parallel circuit labs. (Scroll to bottom for cost-free materials.)

This item offers guided practice to students in designing a variety of circuits, with pop-up explanations to augment simulated images.

A collection of 8 experiments designed to introduce important concepts of electricity to beginning students. Each lab is accompanied by instructional tips to help students form a solid basis for a future study of resistance, Ohm's Law, and potential difference.

#### References and Collections:

Want to go beyond your traditional textbook in a unit on electric circuits? This free web-based textbook offers solid content support for both learners and teachers. The text is student-friendly, blended with many diagrams and photos. Each section is further supplemented with suggested labs and activities. Did we mention, it's **free**?

#### Student Tutorials:

Good jumping-off point for students with little background in electricity. This is Chapter 1 of free online textbook, *All About Circuits*. With entertaining language and detailed diagrams, the author helps students form accurate concepts of electron transfer and charge interaction so they can successfully apply the knowledge in a lab.

This animated tutorial does a great job to promote understanding of current: what it is, how it is produced, and how it moves. The animations show students the difference between DC and AC current flow, and explain how and AC generator works. *Especially recommended for classes where Internet technology is limited: the tutorial is delivered in HTML format.*

#### Assessment:

This is an exemplary set of 50+ short assessments on the basics of electricity and electric circuits. They offer teachers flexibility: 1) students can go online to interactively answer questions and see correct responses, 2) Students can work in small groups to discuss strategies before looking at answers, or 3) Teachers can print the worksheets with answers hidden. Most of the questions require analytical reasoning and will help teachers gauge whether students are getting the big picture.

### Resistance and Ohm's Law (2)

#### Activities:

Robust activity features six molecular models to explore relationships among voltage, current, and resistance. This well-sequenced resource will help learners understand how current is different from voltage and visualize how electron movement is related to conductivity. More advanced students can explore a hydrogen fuel cell model, an incandescent light bulb filament, and electromotive force.

**Item Type:**Interactive Model

**Level:**Grades 9-12

**Duration:**Two Class Periods

In this activity from the PTRA manual "Role of the Laboratory in Teaching Introductory Physics", students set up their first circuit using meters and specially made resistors in heat sink boxes, which do not require alligator clips and don't burn hands.

**Item Type:**Laboratory

**Level:**Grades 9-12

**Duration:**1-2 Class Periods

### Applying Concepts of Electricity (6)

#### Lesson Plans:

A very effective lab for reinforcing the importance of circuit continuity. A lamp is connected to a battery with jumper wires. After measuring normal voltages in a functioning circuit, students break the circuit at each of the four connecting points, then measure again. *Editor's Note: For additional practice in measuring voltage, see "Voltmeter Usage" activity below.*

A collection of 8 experiments designed to introduce important concepts of electricity to beginning students. Each lab is accompanied by instructional tips to help students form a solid basis for a future study of resistance, Ohm's Law, and potential difference.

#### Activities:

A very good introduction to the multimeter, an electronic instrument that measures voltage, current, and resistance. It will help students become comfortable using either a digital or analog multimeter with batteries, an LED, and a simple "hobby" motor.

This is a companion lab to the resource directly above, "Voltmeter Usage". It helps students get practice in using the ammeter function of a multimeter to measure current -- the rate of electron flow in a circuit. Detailed instructions and photos make set-up easy.

A set of 5 creative labs for constructing various types of primary battery cells, all appropriate for use in the high school science classroom. Two of the labs can be performed without corrosive chemicals: the voltaic pile and the lemon cell. The remaining 3 labs use either sulfuric acid or zinc chloride. Each lab contains detailed information on safety precautions and classroom set-up.

#### Assessment:

This is an exemplary set of 50+ short assessments on the basics of electricity and electric circuits. They offer teachers flexibility: 1) students can go online to interactively answer questions and see correct responses, 2) Students can work in small groups to discuss strategies before looking at answers, or 3) Teachers can print the worksheets with answers hidden. Most of the questions require analytical reasoning and will help teachers gauge whether students are getting the big picture.

### Electricity: A Historical Perspective (9)

#### Lesson Plans:

In this lab activity for Grades 5-9, students work in teams to construct a simple telegraph using a battery, wires, and a bulb. By turning the switch on and off, learners "send" messages using International Morse Code. Students then repeat the process sending identical messages on cell phones. Which group can send intelligible messages most quickly? *Editor's Note: This lab activity does not mimic the actual design of the original Morse device, which used electric current to move an electromagnet attached to the key device. Its purpose is to give a simple introduction to signal communications.*

**Item Type:**Lesson Plan

**Level:**Grades 5-9

**Duration:**One Class Period

#### Activities:

In this Java simulation, your students play with a replication of Coulomb's historic torsion balance: a device used to measure electric force between charges. Coulomb's methodical measuring laid the foundation for Coulomb's Law, a fundamental principle of electricity and magnetism.

It sometimes helps students with concept formation if they can see how early scientists made momentous discoveries. In this tutorial, students play with a simulation of the voltaic pile device invented in 1800 by Volta -- commonly known as the world's first battery. Battery cells can still be assembled using this "recipe". *SEE ITEM DIRECTLY BELOW for a lab to construct the voltaic pile device in the classroom.*

If you'd like your students to replicate Volta's groundbreaking experiment with the voltaic pile device (the world's first battery), here is a lesson plan (scroll down to Page 2 of the document). They will construct their own voltaic pile batteries and get a better understanding of how electrochemical reactions work. No harsh chemicals or safety hazards.

#### References and Collections:

In this excellent set of 50+ short biographies, kids can read about the challenges of early inventors AND follow links to simulations of the devices they invented. For example, the Coulomb biography offers a simulation of the torsion balance; the Volta biography has a simulated voltaic pile battery.

A short biography of Charles-Augustin de Coulomb, whose historic work in the 18th century was essential to the development of electromagnetic theory. Read about his experiments with a torsion balance and how he discovered the mathematical relationship known as Coulomb's Law.

#### Student Tutorials:

In the 18th-century, Italian scientist Alessandro Volta proposed the theory that electrical current is generated by contact between different metals. His experimental work resulted in the "voltaic pile" battery, the first known source of sustainable electric current. *For a simulation of the voltaic pile device, see "Activities" above.*

This is a short biography of Charles Augustin de Coulomb, the 18th-century scientist whose experiments with a torsion balance gave rise to Coulomb's Law -- a fundamental principle of physics that defines the electrical force between two charged particles as a predictable mathematical relationship. *For a simulation of Coulomb's torsion balance, see "Activities" above.*

German physicist Georg Ohm was different, and his fellows at the time were not too supportive. This early giant in the field of electricity took a mathematical approach to electric current, at a time when his peers relied almost exclusively on lab experimentation. His perseverance resulted in Ohm's Law, which clarified the relationship between electrical current, resistance, and voltage. This is his biography.