Electrons on the Move
Students explore the phenomenon of electricity as they learn about current electricity and necessary conditions for the existence of an electric current. To make sense of this phenomenon, students construct a simple electric circuit and galvanic cell to help them understand voltage, current, and resistance. They also use the disciplinary core ideas of energy and electric current to better understand the crosscutting concept of energy transfer.
An electric arc produced by strong electric current.Copyright Wikimedia Commons http://commons.wikimedia.org/wiki/File:Lichtbogen_3000_Volt.jpg
An understanding of electric circuits and the concepts of voltage, current and resistance enables engineers to design all sorts of useful devices and inventions that improve our lives. For example, engineers designed photovoltaic (PV) cells, commonly called solar cells, which use sunlight to make electricity. No matter what the source of the electrical power, engineers apply their understanding of how current electricity works to make devices that run the appliances and equipment that are important in our everyday lives.
Photovoltaic cells, or solar cells, arranged in panels so they can be placed on buildings and used to store electricity.Copyright http://www.willoughby.nsw.gov.au/PageZone_residents.asp?z=2&c=223&p=813
After this lesson, students should be able to:
- Understand the concept of current electricity, and the relationship between current, voltage and resistance.
- Recognize that electrical energy in an electric circuit can be converted to different forms of energy, such as motion, thermal and light energy.
- List alternative sources of electricity.
- Recognize that engineers apply their understanding of how electricity works to design appliances and equipment that are important in our everyday lives.