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Book - Chapter 3

The function of Art is to disturb. Science reassures. ~ George Braque


Well, we can call this pile of electrons voltage, designated as V or E, which is measured in volts. The AC current that comes out of the wall socket is 115 volts.


Force = Voltage, Friction = Resistance,  Flow = Current

Voltage (V or E) is electrical potential, or the potential difference between two points, and is measured in volts.


Voltage is electrical pressure or force. It can also be thought of as a potential difference between two points in charged space. The electrical pressure pushing the current is voltage.

To better understand this, think of liquid flowing through a pipe as analogous to electron current flow. Imagine a small bucket filled with water (electrons) attached to a pipe (wire). The more water there is available, the more pressure there is to move water through the pipe. This pressure is comparable with what we call voltage.

If you had a bathtub of water than clearly, this would be a much greater force of voltage pressure than a small bucket of water.


A 3D model of a copper molecule showing regular bonds of copper atoms.
3D model by Todd Swepston

We use the letter I as the symbol to represent electron current moving through a conductor.


3D model of wire and conductors. 


As we learned in Chapter 2, electrons that cascade through conductors are called valence electrons. These valence electrons are the electrons farthest from the nucleus of the atom and therefore are least affected by the attractive forces of the nucleus. Metals are good conductors because they have lots of valence electrons available that can carry electron charge from atom to atom.