1. Electricity, Work, and Power
This module is designed to prepare students to better understand the other modules in the course. It is a review of basic high school-level physics, reminding students of the fundamentals of energy, work, power, and electricity. It includes some hands-on work with electric circuits. This module is not designed to directly address any of the course goals. Its function is rather to prepare the students for success in the subsequent modules.
Students will be able to:
- Distinguish the differences between energy, work, and power, and provide examples of each using appropriate units.
Provide appropriate definitions for the following electrical terms: electron, electric charge, electric potential, resistance, current, power, conductor, semi-conductor, and insulator.
The student will be able to match electrical quantities/properties with the various units of measure used in electrical science (e.g. volts, amps, watts, ohms, amp-hours, kilowatt-hours).
- Identify the elements of an electrical circuit.
State the differences between parallel and series circuits, and note the effects on the electric potential (measured in volts) and current (measured in amps).
- Explain the relationship between the flow of current and magnetism, and show how this is the basis for electric motors and generators.
- Distinguish AC and DC electricity, identify the useful qualities of each, note which devices are associated with each, and describe the role of power inverters.
Context for Use
Description and Teaching Materials
It is important that both the professor and students read the illustrated Student materials page prior to class. The hands-on activity is built around teaching basic electricity.
Class activities for the module.
1. Quiz & Discussion. Since this is likely to be the first module taught, there will be no quiz questions from the students. The class should begin with the required four discussion questions brought by each student. Use the instructor-regulated discussion pedagogy as explained within Student responsibility #3 on the course design and structure page for conducting this exercise. This will be the first time students engage in the process and it is important to be positive and reinforce the asking of higher-cognition questions. Point out how they could modify their questions to reach that goal. For example, a student might ask the question: "Define the word Volt." You could suggest that Volt could be used in a comparison question such as, "Contrast the terms Volt and Amp. What does each measure? How are they related?" Another suggestion could be, "If one wanted to produce the maximum voltage, would it be better to put solar panels parallel to each other, or in series in a circuit? Explain why."
2. Student Presentation. Since this will be the second class meeting, you may not think there is enough lead time to have a student assemble a presentation, and you may forgo this activity for this unit. However, if you think it will work, here are some suggested questions. This activity involves peer instruction.
1. Benjamin Franklin was an early pioneer in the study of electricity. Choose one of his contributions to understanding and using electricity, and explain what he discovered. Discuss how this discovery is important today.
2. Explain the difference between AC and DC electricity. Give examples where each is used. Discuss the advantages and disadvantages of using each.
3. When did electricity become a regular feature of life in the United States? Discuss at least three different ways in which electricity changed society.
3. Hands-on laboratory work. This activity will involve Cooperative Learning as the students will work in groups to accomplish each task, and teaching with interactive demonstrations. A handout for the students that explains each activity is found at: Exercises for Electricity, Work and Power (Microsoft Word 2007 (.docx) 16kB Jun28 17). Spreadsheets across the Curriculum will be useful to help the student use Excel to do the calculations and present their work.
4. Systems Thinking. It is important that students understand the material in this course in a connected way. As this will be the first module they will experience, it is appropriate to introduce the concept of systems thinking. The simple electric motor the students build provides an excellent example of a system. After completing the hands-on laboratory work, have the students diagram the electric motor as a system. Each component should be labeled. Ask them to trace the flow of energy through the system. They should be able to identify the 1.5 volt battery as the source of electrical energy and understand that it is converted to mechanical energy and heat by the use of an electromagnet. They should be able to identify the battery as the reservoir of stored chemical energy. They should understand that even though the circuit is closed, the high-energy electrons generated in the battery do transfer some of their energy to making motion and heat before returning to the battery. Thus, the system is open even though the circuit is closed, as the system loses energy to the surrounding environment.
- Basic circuit kits that include batteries and light bulbs
- Volt-ohm meter
- Citrus fruit, steel paper clip, copper penny or bronze drawing pin, and low-voltage light bulb
- Insulated magnet wire and iron nail for making electromagnets, and paper clips for testing
- D-batteries, wires, battery holder, clips
- A "World's Simplest Motor Kit"
Teaching Notes and Tips
A detailed assessment system for the entire course is presented on the course assessment page. Below are questions for the Pre/Post Test. One approach is to have the students take the pretest for all the modules at the very beginning of the class, and then to administer it again at the end of the class to document advancement in learning.
A. Pre/Post Test Questions for Module 1: Energy, Work, and Electricity. An objective test will be administered during the first and last week of the course to quantify mastery of basic information related to the course and InTeGrate goals. The students will receive up to 2 extra credit points (course grade is based upon 100 total points) for completing the pretest. They will earn up to 5 points of regular credit for completing the post-test. The percentage of correct answers on the pre/post test will be used to determine the number of points awarded each time (product of decimal fraction of correct answers times the 2 or 6 points available in each case).
References and Resources
Suppliers of basic circuit kits:
Simple motor kit:
Basic concepts of circuits:
- All about Circuits: Chapter 1 - Basic Concepts Of Electricity
- Electrical Circuits: The Basics YouTube video
It would be useful for students to view this video prior to coming to class, as that will leave more time for the hands-on activity. But you may also use it as an introduction to the hands-on experiments. Seeing it twice will provide reinforcement of basic concepts.
The following references provide nice background reinforcement for instructors. Professors may also want to include some of these videos in the class time, or a required viewing for students prior to coming to class.
Elector magnets and Faraday's law
Electric motor and generator
AC induction motor
- Introduction to Grid Tie Inverters - Part 1 YouTube video
- Introduction to Grid Tie Inverters - Part 2 YouTube video
- Understanding Power Supplies, Generators, AC and DC YouTube video
How batteries work