Chapter 18: Electric Potential and Capacitance © 2016 Pearson Education, Inc.

Goals for Chapter 18 To calculate electrical potential energy. To define potential. To study equipotential surfaces. To examine capacitors. To determine electrical field energy. © 2016 Pearson Education, Inc.

Electrical Potential and Voltage … Obvious and Not © 2016 Pearson Education, Inc.

Electrical and Gravitational Forces − Figures 18.1−18.2 The forces are similar and conservative. © 2016 Pearson Education, Inc.

Work and Energy Changes − Figure 18.3 Work is done on the charge by the field. © 2016 Pearson Education, Inc.

Very High Energies Are Needed to Span Large Potentials Lightning arcs represent billions of joules of energy. © 2016 Pearson Education, Inc.

Parallel Plates and Energy Conservation –Example 18.2 See Figure 18.8 and the worked example on page 568. © 2016 Pearson Education, Inc.

Potential of Point and Plate Charges –Examples 18.3 and 18.4 Refer to Figures 18.9 and 18.10 with worked examples on pages 570 and 571. © 2016 Pearson Education, Inc.

The Equipotential Map Around Charges –Figure 18.11 Around a charge or arrangement of charges, regions of equal potential may be drawn as equipotential lines. © 2016 Pearson Education, Inc.

Equipotential Lines May Not Cross – Figure 18.12 Considering conduction and geometry one may prove why the lines do not cross. Refer to page 573 in your text. © 2016 Pearson Education, Inc.

The Capacitor – Figures 18.17 and 18.18 Devices may be constructed which separate two conductors of various sizes with materials of various conductance. © 2016 Pearson Education, Inc.

The Symbol and Units of Capacitance –Figure 18.19 Refer to pages 575–578 in your text. Define the Farad and follow Examples 18.6 and 18.7. © 2016 Pearson Education, Inc.

Capacitors Are Often Joined – Figure 18.21 Like resistors, capacitors may be combined sequentially (in series). © 2016 Pearson Education, Inc.

Capacitors Are Often Joined – Figure 18.22 Like resistors, capacitors may be combined in simultaneous fashion (in parallel). © 2016 Pearson Education, Inc.

Capacitors Store Energy – Example 18.9 This is the whine you can hear while an electronic flash charges. Refer to the worked example on pages 602–603. © 2016 Pearson Education, Inc.

What Is Between the Conductors? – Figures 18.26 and 18.27 As we stated on an earlier slide, the amount of charge that may be stored in a capacitor depends in part on the "filler." © 2016 Pearson Education, Inc.

Capacitors with Different Dialectrics – Figure 18.28 Select the dialelectric from Table 18.1. © 2016 Pearson Education, Inc.

Calculation with a Specific Dialectric – Example 18.10 Refer to Figure 18.29 and the worked example on page 585. © 2016 Pearson Education, Inc.