ECE 22X: Text Errata
Fundamentals of Electric Circuits, 2nd ed, 1st printing
Alexander and Sadiku

See the official errata and errata from the 1st edition as well.

Chapter 1

• Page 17: In Example 1.9, the fourth line should read "Over 300 kWh per month...", not "Over 200 kWh per month..." as stated.
• Page 20: At the bottom of the page in Step 4, the equation for i₂ should be v₂/8, not v1/8 as listed. The same applies to all of the equations that follow.

Chapter 2

• Page 64: The voltage source in problem 2.7 should have units of volts (V), not amperes (A).
• Page 69: Problem 2.44b requires a delta-wye transform to solve, but this problem is in a problem section that only covers through Section 2.6 of the chapter. This circuit should be moved to a later problem number that includes problems from Section 2.7 where delta-wye transforms are covered.

Chapter 3

• Page 100: The first sentence in the second paragraph has a typo. The word throught should be throughout.

Chapter 4

• Page 133: In Figure 4.13 (c) the current labeled i₂ should be i₃ .
• Page 146: In Example 4.12, the resistance RN should be 5 , not 1/5 as stated.
• Page 164: The short circuit in problem 4.37 should not be there.

Chapter 5

• Page 169: Polarity on the Op Amp in Figure 5.7 is wrong. As shown, the op amp has positive feedback and would saturate. If the polarity of the op amp is corrected, the answers are vo = 9.000 V and io = 650.0 microamps.
• Page 171: The polarity is wrong again in Figure 5.9, same as Figure 5.7.
• Page 173: The first equation in example 5.4 uses 40 and 20 instead of 40 k and 20 k.
• Page 177: The final equation should be "-0.8 - 4 = -4.8 mA", not "-0.8 - 0.4 = -1.2 mA".
• Page 192: Figure 5.51 used from problem 5.13 has the polarity of the op amp wrong. As shown, the op amp does not have negative feedback.
• Page 198: None of the possible answers in problem 5.5 are correct. The correct answer is -10 microvolts.
• Page 199: Figure 5.89 used for problem 5.72 has the polarity of the left-most op amp wrong. As shown, the op amp does not have the requisite negative feedback.

Chapter 6

• Page 214: The second paragraph should read, "..., assuming the passive sign convention...", not "...positive sign convention."
• Page 229: Example 6.12 assumes that the 4 H inductor in the upper-left portion of the circuit is a 2 H inductor.
• Page 217: The answers to practice problem 6.3 should be +93.14 mV and +1.736 V
• Page 230: In practice problem 6.12 the answers to part c are given in the wrong order. The answers listed are for v1, v2, and v, in that order.
• Page 233: Figure 6.38 should have the vertical axis labeled vo, not vi. This is a plot of the output voltage versus time, not the input voltage.
• Page 236: The equation in the 2nd summary point in Section 6.7 is incorrect. The final term in the right hand expression should be v(t0), not i(t0).
• Page 237: The equation in the 5th summary point in Section 6.7 is incorrect. The final term in the right hand expression should be i(t0), not v(t0).
• Page 245: The expression next to the switch should only be "t=0", not "t=0 A".

Chapter 7

• Page 265: The impulse in Figure 7.32b at t=0 should not be there.
• Page 289: In Example 7.19, the first sentence should read: "..., 0 < R2 < 2.5 M", rather than ..., 0 < R < 2.5 M".
• Page 295: The last sentence should begin, "Because most practical circuits have losses, ..."
• Page 300: To match the answer in the appendix, problem 7.28 should ask to sketch the waveform i(t) = r(t) - r(t-1) - u(t-2) - .... The book has the sign of the second term wrong.
• Page 305: In Figure 7.128 for problem 7.60, there should not be a wire drawn from the output of the op amp to the node connecting the 20k and 100k resistors. As drawn, the 100k resistor is shorted out and has no effect on the circuit. The solution assumes this wire is not there.
• Page 305: In problem 7.71, the output resistor should be labled as 8 k.

Chapter 8

Chapter 9

• Page 370: The third paragraph is ludicrous. Political events and economic fluctuations are not sinusoidal.
• Page 401: In the summary section 4, the equation for admittance Y is Y = 1/Z = G(w) + B(w), not Z = 1/Y = G(w) + B(w)

Chapter 10

Chapter 11

• Page 467: In Example 11.6, the current is calculated incorrectly. In the denominator of Vth/(Zth + RL), the real part should be 24.25 + 9.412 = 33.7 , not 33.39 as shown.
• Page 467: In Practice Problem 11.6, the maximum average power is 6.86 W, not 9.883 W as listed.

Chapter 12

Chapter 13

• Page 566: The fourth line from the top of the page should refer to section 13.4, not 3.4 as stated.

Chapter 16

• Page 720: The units of the current source should be amps, not volts.
• Page 721: In practice problem 16.2, note that, since the voltage input is multiplied by u(t), the voltage source is a short for all t < 0 and iL(0) = 0.
• Page 732: in the equation just before equations (16.22), the X and Z should be bold indicating vectors. In equations (16.23, 24, and 25), the Xs, Ys, and Zs should all be bold.
• Page 739: Equation 16.30 is wrong.
• Page 751: The 1 ohm resistor in Figure 16.55 for Problem 16.18 was drawn as an inductor in the circuit diagram.
• Page 756: The leftmost capacitor is labeled as 0.5F. It should be 0.5 micro-Farads.

Chapter 19

• Page 899: In problem 19.47 the top of the 2 ohm resistor and the dependent voltage source should not be connected.

Appendicies

• Page A-15: The answer to (c) in Practice Problem B.3 should be 6.045 + j11.53, not 6.054 +j11.53 as listed.
• Page A-97: For problem 15.9a the second term should be -2exp{-2s}/s, not -2exp{-2s}/s^2.