1. Chapter 1Electric Circuit Variables

2. History of Electrical Science • Amber의 정전기• Electrical Generator• Battery• Positive & Negative Charge• Electron vs. Ion• Defibrillator Electrical stimulation to a body Leyden jar for retaining electrical charges

3. Electric Circuits and Current Flow Figure 1.3-1A simple circuit. • Charge : quantity of electricity responsible for electric phenomena • Current : time rate of flow of electric charge past a given point • Direct current : current of constant magnitude • Time-varying current : current of varying magnitude

4. Electric Circuits and Current Flow Figure 1.3-3Current in a circuit element. Figure 1.3-4 A direct current of magnitude I. Figure 1.3-5(a) A ramp with a slope M. (b) a sinusoid. (c) An exponential. I is a constant. The current I is zero for t<0.

5. Electric Circuits and Current Flow Example 1.3-2 Example 1.3-3

6. Voltage, Power and Energy Figure 1.5-1Voltage across a circuit element • Voltage : energy required to move a positive charge from – to + • Energy : capacity to perform work • Power : time rate of expending or absorbing energy Figure 1.6-1 (a) The passive convention use for element voltage and current. (b) The passive convention is not used.

7. Power and Energy Table 1.6-1Power Absorbed or Supplied by an Element

8. Power and Energy Example 1.6-2 Example 1.6-3

9. Circuit Analysis and Design Figure 1.7-1The problem-solving method.

10. Circuit Analysis and Design Figure 1.7-2An element with a voltmeter and ammeter. Example 1.7-1 Figure 1.7-3The circuit from Figure 1.7-2 with the ammeter probes reversed.

11. Jet Valve Controller Figure 1.9-1An element with a voltmeter and ammeter.