Chapter 28 46. (a) 2.52 s (b) 21.6 microC (c) 3.40 s 48. 721 kOhms 50. (a) by integration, U_C = (1/2)C(EMF)² and energy out from battery = C(EMF)² (b) by integration, heat from resistor = (1/2)C(EMF)² 52. 2.35 MOhms F57. proof Chapter 31 50. 42 V + (20 V/s)t 58. (a) 238.7 W (b) 154.8 W (c) 393.5 W 60. (a) 18.7 J (b) 5.10 J (c) 13.6 J F46. r=11.4 cm; N=35 turns Chapter 33 4. (a) 6 microseconds (b) 167 kHz (c) 3 microseconds 10. proof 12. (a) 3.6 mH (b) 1326 Hz (c) 189 microseconds 16. (a) Q/2 (b) (sqrt3/2)I 30. (a) 0.283 A (b) 2.26 A 32. 0.6 A for all frequencies 34. (a) 5.22 mA (b) zero (c) 4.52 mA 36. (a) 39.1 mA (b) zero (c) -33.9 mA 44. (a) 16.6 Ohms (b) 422 Ohms (c) 521 mA (d) 33.2 Ohms (e) 408 Ohms (f) 539 mA 48. (a) 796 Hz (b) same (c) decrease (d) increase 50. 100 V (you must carefully explain why) 52. (a) taking energy (b) supplying energy 54. proof plus explanations for limiting cases 60. (a) 76.4 mH (b) yes; 17.8 Ohms; resistor would consume energy, not store it G1. proof G2. proof G3. proof Chapter 34 Q2. into the page 2. (a) 4.71 mHZ (b) 212 s 6. 4.74 m 14. 1.19 MW/m² 16. Bmax = 3.42 microT; Emax = 1.03 kV/m 34. 4.55 x 10^-4 38. 19.0 W/m² 40. (a) 15.9% (b) 84.1% F22. at 5 km, 0.268 V/m, 0.894 nT; at 100 km, 0.0134 V/m, 44.7 pT F32. 2.90 nJ/m³ 18.1 V/m, 60.4 nT