Their application explains how heaters and light bulbs work, how motors and generators work, and how sound is generated by speakers and recorded with microphones on magnetic tape, or burned into a laser disk. Transistor amplifiers, integrated circuits, and their application in amplifiers, computers, control circuits, electromechanical devices, and power distribution have this same basis. The approach that we have taken in this course is to look at electronics from the aspect of the basic electrical components, i.e. power supplies, resistors, capacitors, and inductors. The voltage sources we discussed were the battery, which produces DC through chemical reaction, and the AC generator, or the voltage present at every electrical outlet. Resistors were introduced as representing a load, or energy consuming device.
Resistors are common in electrical circuits.
Their composition was discussed in the links. Carbon resistors have a color code that indicates their resistance and tolerance. Tolerance is the range of deviation from the indicated value that is tolerated and is generally plus or minus 5 or 10 percent. Series resistances all experience the same current and divide the source voltage among themselves. Series resistive circuits are called voltage dividers .