Summary of Circuits E. Alexander Burt Potomac School
Review: Electric current requires... <ul><li>Charge carriers that can move – usually electrons moving from atom to atom within a conductor
A conductor – a path for the current to flow. Usually this is a metal object.
A reason for the charge to move. This is provided by an electric field, and the electric field comes from a difference in voltage. </li></ul>
Review: A closer look at Voltage <ul><li>When work is done to separate objects that want to be together, potential energy is stored: </li></ul>http://sdsu-physics.org/physics180/physics180B/p180b_images/e_potentialenergy.gif
Voltage, part deux <ul><li>The work done = the potential energy
Voltage is like height. In order for charge to flow through a conductor, there must be a difference in voltage between one end and the other. </li></ul>
Batteries and power supplies <ul><li>Something has to do work to “lift” the charge up to a voltage. </li><ul><li>That work might come from chemical energy in a battery
That work might come from the power company (and they will charge us money for it, too) </li></ul><li>In either case, think of them as “escalators of charge” lifting charge up through a height (voltage). </li></ul>
Current <ul><li>Just like water current, electrical current is a flow
In this case, it's a flow of charge over time. We use the letter I for current.