Learners build simple parallel circuits by using wires, batteries, switches, and light bulbs.
After completing this tutorial, you will be able to complete the following:
Before mankind understood or harnessed electricity, its effects were observed. Lightning has always been regarded as a powerful and fearful phenomenon, and cultures throughout history have recognized it as the calling card of deity or deity itself. Electricity was observed in places other than the sky, though. Ancient Egyptian texts from 2750 BC discussed electric fish and recorded that people received shocks from these creatures they called the "Thunder of the Nile." Author and Naturalist, Pliny the Elder, asserted in the first century AD that shocks could be administered by catfish and torpedo rays and that these shocks could travel along conducting objects. The ancient Greeks used amber in decoration and noticed that rubbing amber caused the attractive force that we now call static electricity.
Around 1600, William Gilbert, physician to Queen Elizabeth I, studied electricity and magnetism and used the term elektron, Greek for amber, to coin the word electricity. After extensive research on electricity, in June 1752, Benjamin Franklin conducted his famous kite experiment. When Mr. Franklin flew his kite in the storm-charged sky, he observed the small fibers of the kite string standing on end and sparks jumping from the key to his hand and concluded that lightning must be electrical. In the nineteenth century, Michael Faraday invented the electric motor and Georg Ohm defined the relationship between voltage, current, and resistance and published a book featuring Ohm's law. The twentieth century witnessed huge advances in electrical engineering. With pioneers such as Nikola Tesla, Thomas Edison, George Westinghouse, Alexander Graham Bell, and Lord Kelvin, a Second Industrial Revolution was born.
We harness and use electricity in almost every area of our lives. For electricity to power our modern devices, it must flow in a current and must make a complete circuit. There are two kinds of circuits, series circuits and parallel circuits. Components connected in a series are along a single path. The electricity flows through all of the components, so that one missing or broken component causes an interrupted circuit and renders the entire circuit unworkable. Examples of series circuits include the batteries in flashlights and some strings of holiday lights. In a parallel circuit, there is more than one path through which the electricity can flow, and the voltage difference is the same across each path. Since there is more than one path through which the electricity can flow, if one path of the circuit is opened, the electricity continues to flow through and power the other paths. Examples of parallel circuits include the wiring systems in homes and automobiles.
|Approximate Time||20 Minutes|
|Pre-requisite Concepts||circuit components, closed circuits, switches|
|Type of Tutorial||Concept Development|
|Key Vocabulary||battery, bulb, circuit|