This preview shows page 1. Sign up to view the full content.
Unformatted text preview: orkbook Contents CHAPTER 2
2.45 Basic Laws
a What value of R in the circuit of Fig. 2.109 would
cause the current source to deliver 800 mW to the
resistors? R 69 R
R b 30 mA (b)
R R Figure 2.111
∗ Figure 2.109
2.46 2.48 For Prob. 2.45. For Prob. 2.47. Obtain the equivalent resistance Rab in each of the
circuits of Fig. 2.112. In (b), all resistors have a
value of 30 . Obtain the equivalent resistance at the terminals a b
for each of the circuits in Fig. 2.110. 30 Ω
20 Ω a 10 Ω 30 Ω
10 Ω 10 Ω a 20 Ω 10 Ω 60 Ω
20 Ω 40 Ω 50 Ω 80 Ω b b (a)
(a) a
30 Ω 30 Ω
25 Ω 10 Ω 20 Ω a
5Ω b 15 Ω (b)
b Figure 2.112 (b) Figure 2.110
∗ 2.47 For Prob. 2.46. 2.49 For Prob. 2.48. Calculate Io in the circuit of Fig. 2.113. Find the equivalent resistance Rab in each of the
circuits of Fig. 2.111. Each resistor is 100 . Io a 20 Ω
24 V +
− 60 Ω 40 Ω
10 Ω 50 Ω 20 Ω
b
(a)  For Prob. 2.49. asterisk indicates a challenging problem. v v ∗ An Figure 2.113  eText Main Menu  Textbook Table of Contents  Problem Solving Workbook Contents 70 PART 1 2.50 DC Circuits Determine V in the circuit of Fig. 2.114. I 30 Ω
16 Ω
+
V
− +
− 100 V 40 W 50 W +
− 100 V 15 Ω 30 W 10 Ω 35 Ω 12 Ω Figure 2.117 20 Ω For Prob. 2.53. 2.51 As a design engineer, you are asked to design a
lighting system consisting of a 70W power supply
and two lightbulbs as shown in Fig. 2.118. You must
select the two bulbs from the following three
available bulbs. For Prob. 2.50. Find Req and I in the circuit of Fig. 2.115. I R1 = 80 , cost = $0.60 (standard size)
R2 = 90 , cost = $0.90 (standard size)
R3 = 100 , cost = $0.75 (nonstandard size) 2Ω 4Ω 1Ω 6Ω The system should be designed for minimum cost
such that I = 1.2 A ± 5 percent. 12 Ω I
20 V 8Ω +
− 2Ω +
70 W
Power
Supply 4Ω
3Ω 10 Ω Figure 2.118 Req Figure 2.115
Section 2.8
2.52 If an ammeter with an internal resistance of 100
and a current capacity of 2 mA is to measure 5 A,
determine the value of th...
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.
 Spring '12
 bkav

Click to edit the document details