Chapter 22: Alternating Current © 2016 Pearson Education, Inc.

Goals for Chapter 22 To study phasors and alternating current. To explore and calculate resistance and reactance. To diagram and solve examples of the series R-L-C circuit. To calculate and graph power in alternating-current circuits. To study series and parallel resonance. © 2016 Pearson Education, Inc.

Alternating Current − Figure 22.1 A coil of wire rotating with constant angular velocity in a magnetic field develops a sinusoidal oscillating current. The potential will vary from a maximum V at a frequency ω (or, by a factor of 2π, as f in Hz). © 2016 Pearson Education, Inc.

What Are Phasors? – Figure 22.2 Phasors are graphic representations of location. In two dimensions, you can locate a unique point with a radius vector of length L and its angle with respect to zero. This figure refers to Conceptual Analysis 22.1. © 2016 Pearson Education, Inc.

Root-Mean-Square Averages – Figure 22.4 Refer to Example 22.1 in your text. © 2016 Pearson Education, Inc.

Resistance and Reactance – Figure 22.6 For a circuit such as the one shown at the right, there is a resistor and one can calculate the potential and current. BUT, in an AC circuit, these are functions of time. © 2016 Pearson Education, Inc.

An Inductor in a Circuit – Figure 22.7 Refer to Example 22.2 in your text. The circuit leads to the rms graph which leads to the phasor diagram. © 2016 Pearson Education, Inc.

A Capacitor in an AC Circuit – Figure 22.8 Even though we don't think of capacitors as transparent to current, we can have one plate charge, then immediately have the opposing plate charge. We think of AC as going past or through a capacitor. © 2016 Pearson Education, Inc.

Capacitors and AC Circuits – Figures 22.9 and 22.10 Refer to the worked examples in Conceptual Analysis 22.2 and also in Example 22.3. © 2016 Pearson Education, Inc.

The Series R-L-C Circuit – Figure 22.12 Consumer electronics would be a good place to find such a circuit. © 2016 Pearson Education, Inc.

Current and Voltage May be Found – Figure 22.13 As in Figure 22.8, we can follow the logic from circuit to phasor diagrams here, too. © 2016 Pearson Education, Inc.

R-L-C Circuits – Figure 22.14 Refer to Example 22.4 and Conceptual Analysis 22.3. You will want to take advantage of Problem Solving Strategy 22.1. © 2016 Pearson Education, Inc.

Power in Alternating Current Circuits – Figure 22.15 AC current behaves differently with respect to power than does DC current. It was the crucial difference that made long-distance wiring possible. © 2016 Pearson Education, Inc.

Power in AC Circuits – Figures 22.16 and 22.17 Follow from phasor diagram to Conceptual Analysis 22.4 to Examples 22.5 and 22.6. © 2016 Pearson Education, Inc.

Series Resonance – Figure 22.18 Since the AC flow is expressed in terms of frequency, it follows that just like in music, these frequencies can resonate. © 2016 Pearson Education, Inc.

Series Resonance – Figures 22.19 and 22.20 A generic diagram illustrating waveforms in resonance. Refers to Conceptual Analysis 22.5 and Example 22.7. © 2016 Pearson Education, Inc.