2 w power absorbed by the 6 k 12 k a notice that the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: + vo − 9000 (30 A) = 10 mA 9000 + 18,000 i2 io 30 mA po = vo io = 180(30) mW = 5.4 W resistor is i1 + vo − 9 kΩ 18 kΩ (b) 2 p = iv = i2 (i2 R) = i2 R = (10 × 10−3 )2 (12,000) = 1.2 W Power absorbed by the 6-k 12 kΩ (a) Notice that the voltage across the 9-k and 18-k resistors is the same, and vo = 9,000i1 = 18,000i2 = 180 V, as expected. (b) Power supplied by the source is (c) Power absorbed by the 12-k 9 kΩ Figure 2.44 resistor is For Example 2.13: (a) original circuit, (b) its equivalent circuit. 2 p = i2 R = (10 × 10−3 )2 (6000) = 0.6 W Power absorbed by the 9-k p= resistor is 2 (180)2 vo = = 3.6 W R 9000 or p = vo i1 = 180(20) mW = 3.6 W Notice that the power supplied (5.4 W) equals the power absorbed (1.2 + 0.6 + 3.6 = 5.4 W). This is one way of checking results. PRACTICE PROBLEM 2.13 For the circuit shown in Fig. 2.45, find: (a) v1 and v2 , (b) the power dissipated in the 3-k and 20-k resistors, and (c) the power supplied by the current source. 1 kΩ 3 kΩ + v1 − Figure 2.45 10 mA 5 kΩ + v2 − 20 kΩ For Practice Prob. 2.13. Answer: (a) 15 V, 20 V, (b) 75 mW, 20 mW, (c) 200 mW. @ | v v Network Analysis | e-Text Main Menu | Textbook Table of Contents | Problem Solving Workbook Contents 50 PART 1 † R1 R2 R3 R4 vs + − R5 Figure 2.46 R6 The bridge network. DC Circuits 2.7 WYE-DELTA TRANSFORMATIONS Situations often arise in circuit analysis when the resistors are neither in parallel nor in series. For example, consider the bridge circuit in Fig. 2.46. How do we combine resistors R1 through R6 when the resistors are neither in series nor in parallel? Many circuits of the type shown in Fig. 2.46 can be simplified by using three-terminal equivalent networks. These are the wye (Y) or tee (T) network shown in Fig. 2.47 and the delta ( ) or pi ( ) network shown in Fig. 2.48. These networks occur by themselves or as part of a larger network. They are used in three-phase networks, electrical filters, and matching networks. Our main interest here is in...
View Full Document

This note was uploaded on 07/16/2012 for the course KA KA 2000 taught by Professor Bkav during the Spring '12 term at Cambridge.

Ask a homework question - tutors are online