Alternating Current Circuits Based on Serway and Jewett e6

CHAPTER OUTLINE 1 AC Sources 2 Resistors in an AC Circuit 3 Inductors in an AC Circuit 4 Capacitors in an AC Circuit 5 The RLC Series Circuit 6 Power in an AC Circuit 7 Resonance in a Series RLC Circuit 8 The Transformer and Power Transmission 9 Rectifiers and Filters

Chapter Objectives 1-Describe alternating current (AC) circuits. 2-Investigate the characteristics of simple series circuits that contain resistors, inductors, and capacitors and that are driven by a sinusoidal voltage 3- The illustration of the functions of some useful device such as transformers, power transmission, and electrical filters will be a conclusive end of this course.

1 AC Sources

2 Resistors in an AC Circuit

Phasor Diagram

Phasor diagram, R

AC terminology The average value of the current over one cycle is zero. But, does not matter with the resistance, R P=i 2 R The average value of the instantaneous current, The square root of the mean

Example This equation states that an alternating current whose maximum value is 2.00 A delivers to a resistor the same power as a direct current that has a value of (0.707)(2.00 A) = 1.41 A. Thus, the average power delivered to a resistor that carries an alternating current is When we speak of measuring a 120-V alternating voltage from an electrical outlet, we are referring to an rms voltage of 120 V. A quick calculation using Equation 33.5 shows that such an alternating voltage has a maximum value of about 170 V.

3 Inductors in an AC Circuit

Phasor diagram, L I L lags behind  v L

4 Capacitors in an AC Circuit

Phasor diagram, C

5 The RLC Series Circuit

6 Power in an AC Circuit 1/2 0 Power factor

7 Resonance in a Series RLC Circuit A series RLC circuit is said to be in resonance when the current has its maximum value.

ASSIGNMENT 1-Redraw the resonance curves, I and P, using EXCELL software 2- Read sections 33.8 and 33.9