Solution Manual For Electronics Fundamentals: A Systems Approach, 1st Edition

CHAPTER 2 VOLTAGE, CURRENT, AND RESISTANCE BASIC PROBLEMS SECTION 2-2 Electrical Charge 1. Q = (charge per electron)(number of electrons) = (1.6  1019 C/e)(50  1031e) = 80  1012 C 2. (6.25  1018 e/C)(80  106 C) = 5  1014 e 3. The magnitude of the charge on a proton (p) is equal to the magnitude of the charge on the electron (e). Therefore, (1.6  10-19 C/p)(29 p) = 4.64  10-18 C 4. (1.6  10-19 C/p)(17 p) = 2.72  10-18 C SECTION 2-3 Voltage V  W 10 J = 10 V  Q 1C 5. (a) 6. V  W 500 J =5V  Q 100 C 7. V  W 800 J = 20 V  Q 40 C 8. W = VQ = (12 V)(2.5 C) = 30 J 9. V= (b) V  W 5J = 2.5 V  Q 2C (c) V  W 100 J =4V  Q 25 C (b) I Q 10 C  = 20 A t 0.5 s (c) I Q 5C  = 2.5 A t 2s W 2.5 J = = 12.5 V Q 0.2 C SECTION 2-4 Current 10. I= 11. (a) 12. Q 0.2 C = = 20 mA t 10 s Q 75 C  = 75 A t 1s Q 0.6 C I  = 0.2 A t 3s I 7 Q ; t Q 10 C =2s  I 5A 13. I 14. Q = I  t = (1.5 A)(0.1 s) = 0.15 C t= SECTION 2-5 Resistance 15. A: B: C: Blue, gray, red, silver: 6800   10% Orange, orange, black, silver: 33   10% Yellow, violet, orange, gold: 47,000   5% 16. A: Rmin = 6800   0.1(6800 ) = 6800   680  = 6120  Rmax = 6800  + 680  = 7480  Rmin = 33   0.1(33 ) = 33   3.3  = 29.7  Rmax = 33  + 3.3  = 36.3  Rmin = 47,000   (0.05)(47,000 ) = 47,000   2350  = 44,650  Rmax = 47,000  + 2350  = 49,350  B: C: 17. (a) (b) 1st band = red, 2nd band = violet, 3rd band = brown, 4th band = gold 330 ; orange, orange, brown, (B) 2.2 k: red, red, red (D) 39 k: orange, white, orange (A) 56 k: green, blue, orange (L) 100 k: brown, black, yellow (F) 18. (a) (b) (c) 36.5   2% 2.74 k  0.25% 82.5 k  1% 19. (a) (b) (c) Brown, black, black, gold: 10  ± 5% Green, brown, green, silver: 5,100,000  ± 10% = 5.1 M ± 10% Blue, gray, black, gold: 68  ± 5% 20. (a) (b) (c) 0.47  ± 5%: yellow, violet, silver, gold 270 k ± 5%: red, violet, yellow, gold 5.1 M ± 5%: green, brown, green, gold 21. (a) (b) (c) Red, gray, violet, red, brown: 28,700  ± 1% = 28.7 k ± 1% Blue, black, yellow, gold, brown: 60.4  ± 1% White, orange, brown, brown, brown: 9310 ± 1% = 9.31 k ± 1% 22. (a) (b) (c) 14.7 k ± 1%: brown, yellow, violet, red, brown 39.2  ± 1%: orange, white, red, gold, brown 9.76 k ± 1%: white, violet, blue, brown, brown 23. (a) (c) (e) 220 = 22  823 = 82 k 560 = 56  24. 500 , equal resistance on each side of the contact. (b) (d) (f) 472 = 4.7 k 3K3 = 3.3 k 10M = 10 M 8 SECTION 2-6 The Electric Circuit 25. There is current through Lamp 2. 26. See Figure 2-1. Figure 2-1 SECTION 2-7 Basic Circuit Measurements 27. See Figure 2-2(a). Figure 2-2 28. See Figure 2-2(b). 29. Position 1: V1 = 0 V, V2 = VS Position 2: V1 = VS, V2 = 0 V 30. See Figure 2-3. 31. On the 600 V DC scale: 250 V 32. R = (10)(10 ) = 100  33. (a) (b) (c) 34. Figure 2-3 2(100 ) = 200  15(10 M) = 150 M 45(100 ) = 4500  Figure 2-4 See Figure 2-4. 9 ADVANCED PROBLEMS Q t Q = I  t = (2 A)(15 s) = 30 C W 1000 J V= = 33.3 V  Q 30 C 35. I= 36. I= 37. Total wire length = 100 ft Resistance per 1000 ft = (1000 ft)(6 /100 ft) = 60  Smallest wire size is AWG 27 which has 51.47 /1000 ft 38. (a) (b) (c) 39. The circuit in (b) can have both lamps on at the same time. 40. There is always current through R5. 41. See Figure 2-5. Q t Q = (number of electrons) / (number of electrons/coulomb) Q 9.184 102 C 574 1015 e 2 Q= = 9.184  10 C I = = 0.367 A  t 250 103 s 6.25  1018 e/C 4R7J = 4.7   5% 560KF = 560 k  1% 1M5G = 1.5 M  2% Figure 2-5 42. See Figure 2-5. 10 43. See Figure 2-6. Figure 2-6 44. See Figure 2-7. 11