Alternating Current Circuits
As you study this first section of Chapter 7, you will be challenged to learn and understand the most difficult subject in this book, impedance in alternating current (AC) circuits. Impedance, like the resistance presented in Chapter 2, provides a relationship between electric current and voltage. However, AC signals are more complicated than the (constant) direct current (DC) values of voltage and current discussed. Therefore, you will find that impedance is more involved than resistance. As you progress through this section, you are encouraged to refer to Appendices A, B, and C for a review of (or introduction to) trigonometry, complex numbers, and phasors, respectively.