Editor selections by Topic and Unit

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## AP/Calculus-Based Physics: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 (2)

#### Activities:

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

#### Content Support For Teachers:

The introductory calculus-based physics curriculum often treats electrostatic and circuit phenomena as separate and unrelated. The problem is that students have little framework for understanding electric field, and often proceed with little sense of the true mechanism of a circuit. This article proposes a new and unified approach for teaching circuits. Students first analyze the behavior of the whole circuit based on dynamic atomic-level models, THEN explore potential and current.

### Electrical Charge (4)

#### Activities:

A set of five experiments that help the students relate current with electric charge. They will build a branching circuit, explore electrolysis in two very different ways, and look at electric charge using capacitors. Each lab has explicit diagrams and tips to help teachers confront misconceptions.

This applet simulates the transient behavior that occurs when a capacitor is being charged and discharged. Students can change the magnitudes of the resistance, capacitance, and the voltage of the battery, as well as flip a switch between its two positions.  The applet then graphs both voltage and current in the circuit as functions of time.

#### 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.

#### Content Support For Teachers:

This chapter of an introductory physics textbook provides content support on electrostatics, electric field and potential, current electricity, magnetic field and force, and electromagnetic phenomena.  The author, a veteran professor of physics, has summarized his own notes from "lectures that worked" and blended them with calculus-based practice problems with solutions.

### Moving Charges and Electric Circuits (15)

#### 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.

This stand-out lesson from the Institute of Electrical & Electronics Engineers gives step-by-step instructions for designing and building a voltage divider -- a form of linear circuit capable of producing a wide range of output voltages. Students explore the mathematical relationships of parallel & series resistors as they build LED's. It is intended as the 3rd in a set of circuit lessons by the same publisher.

Item Type: Inquiry-Based Lesson
Level: High School Physics
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.

This applet simulates the behavior of a simple RLC circuit with an AC voltage source.

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

This applet simulates the transient behavior of a simple RC circuit.  Students can change the magnitudes of the resistance, capacitance, and the voltage of the battery, as well as flip a switch between its two positions.  The applet then graphs both voltage and current in the circuit as functions of time.

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:

This page offers detailed background information on 15 different types of batteries.   The author discusses the historical background of each battery, augmented with cross-sectional images and full explanations of how the batteries function.

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?

#### Content Support For Teachers:

This item is an educator's guide featuring easily-understood content support in fundamentals of electricity, electrostatic charge, circuit basics, conductors, and insulators.  Labs and assessments are also included.

This interactive applet displays the phasor diagram for an AC circuit.  Probably best used within a teacher-directed activity, it is intended to show current through a circuit as a function of frequency.  By controlling the frequency, resistance, capacitance, and inductance of the circuit, students can conceptualize the relationship of these variables and better understand how to interpret the related graphs.

This item is a unit of study on electric circuits for beginning high school physics.  Especially noteworthy are the detailed labs that encourage the process of inquiry and promote critical thinking. Other included resources are numerical problems, puzzles, reference materials, and practice test questions/answers.

This is a research article investigating high school and college students'  understanding of how DC circuits work.  The analysis indicates that students, especially females, tend to hold multiple misconceptions, even after instruction.  The main source of misconception, as reported by the article, is with confusion about the underlying mechanism of electric circuits and the meaning of "current".

#### Student Tutorials:

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.

### Electric Force and Coulomb's Law (2)

#### Activities:

Coulomb's Law is used to calculate the electric force between charges.  To help students grasp the underlying concepts, this simulation lets them drag a moveable charge to see the connection between the force vector and proximity to the fixed charge.

#### 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.

### Resistance and Ohm's Law (6)

#### Lesson Plans:

This stand-out lesson from the Institute of Electrical & Electronics Engineers gives step-by-step instructions for designing and building a voltage divider -- a form of linear circuit capable of producing a wide range of output voltages. Students explore the mathematical relationships of parallel & series resistors as they build LED's. It is intended as the 3rd in a set of circuit lessons by the same publisher.

Item Type: Inquiry-Based Lesson
Level: High School Physics
Duration: Two Class Periods

#### Activities:

This java simulation demonstrates the relationship among current, voltage, and resistance.  Students adjust resistance and voltage up or down in a simple circuit and watch the results on a simulated ammeter.

As students adjust current flow in this Java simulation, the resulting changes are represented on both a macro and nanoscale.   This activity helps the beginner understand how electron collision causes resistance.  Try teaming this simulation with the one above on Ohm's Law.

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
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
Duration: 1-2 Class Periods

#### Content Support For Teachers:

This page is a comprehensive tutorial on resistance, accompanied by three interactive simulations.  One allows students to glimpse resistance at a molecular level; the second explores Ohm's Law; and the third introduces the use of color coding in composition resistors.

### Sources of Electrical Energy (1)

#### Content Support For Teachers:

This page offers detailed background information on 15 different types of batteries.   The author discusses the historical background of each battery, augmented with cross-sectional images and full explanations of how the batteries function.

### Applying Concepts of Electricity (7)

#### 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.

Students learn about systems as they reverse-engineer a disposable camera containing both electrical and mechanical components. They create a systems diagram for the deconstructed device. Then, in partnership with other participants across the country, learners will reassemble the device and test their reconstruction against quality controls. The project is free with teacher registration.

Item Type: Digital Telecollaboration
Duration: Multi-Day

#### 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 (8)

#### 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.