Electronics For Dummies, 3rd Edition

Chapter 6

Obeying Ohm’s Law

IN THIS CHAPTER

Understanding how current, voltage, and resistance are governed by Ohm’s Law

Practicing Ohm’s Law by analyzing circuits

Using power as your guide in choosing circuit components

An intimate relationship exists between voltage (the electrical force that pushes electrons) and current in components that have resistance. That relationship is summed up nicely in a simple equation with an authoritative name: Ohm’s Law. In this chapter, you put Ohm’s Law to work to find out what’s going on in some basic circuits. Then you get a look at the role of Ohm’s Law and related power calculations in the design of electronic circuits.

Defining Ohm’s Law

One of the most important concepts to understand in electronics is the relationship between voltage, current, and resistance in a circuit, summarized in a simple equation known as Ohm’s Law. When you understand this equation thoroughly, you'll be well on your way to analyzing circuits that other people have designed, as well as successfully designing your own circuits. Before diving into Ohm’s Law, it may help to take a quick look at the ebbs and flows of current.

Driving current through a resistance ...