Voltage, Current, and Resistance

            I have an amazing story (okay, it’s not that amazing, but the story will help drive my point home) about a cardboard fort, a strand of lights, and a broken bulb. The story however involves details that will need some clarification first, so I am going to leave you on the edge of your seats till later in the week when I publish that one.

           

Electricity. That is the topic that needs to be addressed, and without any further ado, I present: Voltage, Current, and Resistance. My old electronics teacher hated water analogies, so I figure the best way to explain the flow of electrons is with a water analogy.

Pretend your thumb is at the end of the hose.

Imagine a hose. The valve is voltage, or the amount of pressure pushing the electrons, so the more you open the valve, the more pressure you get, or more voltage. The water is the current or the flow of electrons that is being pushed by the voltage, and when you put your thumb at the end of the hose to vary how much water comes out, your thumb becomes resistance.

Now that I got that out of my system lets look at each term individually:

·      Voltage- Voltage is the pressure in a circuit, or “Potential Difference” detailing the difference between the pressure and ground potential or 0 Volts. Voltage is measured in Volts and abbreviated with a V.

·      Current- Current is the number of electrons that flow past a certain point each second. Current is abbreviated with an I, but the measure of current is in Amperes and abbreviated with an A.

·      Resistance- Resistance as the name implies is the restriction to the flow of current in a circuit. Resistance is measured in Ohm’s and abbreviated with the symbol Ω.

When we combine those three aspects we get Ohm’s Law. Named after Georg Ohm, Ohm’s Law states that current flow is directly proportional to the voltage applied and inversely proportional to the resistance. WHAT? As resistance increases, current decreases, and as resistance decreases, current increases. From all those fancy words we get the equations: V=I*R, I=V/R, and R=V/I.

Now that I got through all that, you’re probably wondering when will I ever need to know this? Chances are unless your building circuits, fixing old electronics, matching loads with speakers in live sound settings, or you just like doing physics…never. However, It will allow me to tell in much greater detail why all your Christmas lights go out when its only one bulb that is bad.

A very simple depiction of Ohm's Law, V=I*R, I=V/R, and R=V/I.

...My mistake in "Player Piano" was my failure as a futurist. I did not foresee transistors, and so imagined that super computers would have to be huge, with bulky vacuum tubes taking up a lot of space. -Kurt Vonnegut in "Letters"