Resistors
From Wikicliki
A Resistor is an electrical device that resists the flow of electrical current.
- It creates a drop in voltage between two points.
- Resistors rely on something called Ohm's Law, which maintains that the voltage shift or potential difference between two ends of a conductor is held in proportion to the current moving through the conductor.
- Resistors do not have polarity. You can connect them in any direction you like.
<img src="http://dreamsyntax.org/arduino/resistors.jpg">