In this episode, we'll explore how electric current flows through a circuit.
After defining voltage in last week's T³ video, it's time to talk about current. Electric current is the flow of electric charge, and for most circuits, this is carried out by moving electrons in a wire or other electronic component.
We can measure current by looking at the amount of charge moving past a point (such as in a wire) per unit of time. The SI unit for electric current is the ampere (A), which is coulombs per second (C/s). Note that electrons are generally the charge carrier in a circuit, and they move from lower potential to higher potential. "Conventional current," however, is a measure of positive charge moving in a circuit that moves from higher potential to lower potential, and it moves in the direction opposite of electron flow. We can thank Mr. Ben Franklin for that bit of confusion.
For those of you already familiar with these concepts, I must ask once again for your feedback: What worked, and what would you have done differently? As we make more of these concept videos and tutorials, they will be featured on our education site for teachers, parents and students to freely use and study.
Much of the video was information taken from our "What is a circuit?" written tutorial: