Power in Series R-L Circuit

Basic AC Power POWER TRIANGLE Power in Series R-L Circuit Figure 4 Series R-L Circuit Example: A 200 W resistor and a 50 W X_L are placed in series with a voltage source, and the total current flow is 2 amps, as shown in Figure 4. Find: 1. pf 2. applied voltage, V 3. P 4. Q 5. S Solution: 1. pf cosq q arctan � � � � � � � � X_L R cos � � � � � � � � arctan � � � � � � � � X_L R cos^� � � � � � arctan^� � � � � � 50 200 cos (14°) pf 0.097 2. V IZ Z R² X²_L I R² X²_L 2 200² 50² 2 42,500 (2)(206.16) V 412.3 volts Note: Inverse trigonometric functions such as arctan are discussed in the Mathematics Fundamentals Manual, Module 4, Trigonometry, pages 6 and 7 should the student require review. Rev. 0 Page 5 ES-09