Voltage/Capacitance and Electric Force

Okay, so we learned in the last lovely blogpost that volts are the units of electric potential (not to be confused with electric potential energy, uh-huh.) But voltage is something entirely different. It's the amount of push you get to do something. Now, there's a specific equation to find voltage, or potential difference, in parallel plates. That formula is W=Eqd, where Work equals the product of distance, charge (coulombs) and the electric field (Newtons/coulomb). We also learned about CAPACITANCE :) which is basically short term energy storage. It stores lots and lots and lots of voltage, but not a great deal of charge. You can find this sort of thing in keyboards and touchscreens, which is why I've included a random (and probably sort of lazy) photo of my iPad notes from class. I can't really explain how it works in touchscreens, but I'm assuming its the same principles as the keyboard.

Anyhow, the plates in the keyboard work kind of like this: when you shorten the distance between the plates (aka the space between the key and the board), the voltage decreases, and sends a message to the circuits and the computer to produce whatever letter you just pressed. That is how I am able to type this post, yups. Now here's the technical portion: capacitance is measured in Farads (yes, it sounds very Middle Eastern, get over it) and the equation for it is Capacitance = Permativity of Free Space (a constant, generally air) multiplied by the area of the plates, all divided by the distance between the plates. It's a pretty easy thing to remember. :) See you next week!