Chapter 3

Meeting Up with Resistance

In This Chapter

Creating just the right amount of resistance with fixed and variable resistors

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

If you toss a marble into a sandbox, the marble won’t go very far. But if you toss a marble onto the surface of a large frozen lake, the marble will enjoy a nice little ride before it eventually comes to a stop. A mechanical force called friction stops that marble on either surface — it’s just that the sand provides more friction than the ice.

Resistance in electronics is a lot like friction in mechanical systems: It puts the brakes on electrons (those teeny-tiny moving particles that make up electric current) as they move through materials.

This chapter looks at exactly what resistance is, where you can find resistance (everywhere), and how you ...

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