Publisher Summary This chapter discusses standard RETMA values, color coding, and the methods of obtaining resistance. Resistance to the flow of electricity is greater when the wire or other conductor is very narrow, similar to the flow of water in a very narrow pipe. At higher temperatures, the atoms of the conductive material move around randomly and are therefore not in their usual positions within the material, which also slows the net forward motion to some degree. Also, the electrons tend to collide with each other, which cause them to deviate from a straight path. The heating effect is used in a special type of thermistor device, where temperature can be measured by noting the rise in resistance. The inexpensive resistors to be used in this course are mostly the carbon composition type, which are graphite plus clay with a plastic insulating coating around the outside. The insulating coating around the resistor is usually epoxy plastic. A water pump analog of two resistors in parallel and the electrical example are also discussed in the chapter.