244 Answers- (a) 38.5 Hz, (b) 50.23 Hz, (c) 1 A, 0.1 A. 9. (a) 15.9 kHz, (b) 20, (c) 5 kHz, (d) 13.4 kHz,
18.4 kHz. 10. (a) 33.7 ~zF, (b) 78 ~xF. 11. (a) 12.8 kl~, (b) 6.4 kl'~, (c) 0.127 p,F, (d) 223,
2.8 kHz. 12. (a) 50 kHz, (b) 7.95 kfl, (c) 12.7 fl. 13. (a) 2.8 nF, (b) 7.14 kfl, (c) 37.7, (d)
41.2 mA.
Chapter 7Self-assessment test- [1 7 9 81]. 4. a34. 5o Yes. 6. No.
Problems, ,a, [: ,c, [o 6 ,c, 6][1^31
-12 ,(d) -11 -15- (a) 2x+5y=27 (b) x-y+5z=6
x+3y= 16 x+y+z =0
-x - 3z = 1
4"4"5"25"6"5"178 ~l =15"7"(-1)z+12 6 4 = -2" $" 3"64 A" 9. 0"94 A'10. x'2
- -20.6 mA. 12. (a) 0 A, 2 A, 4 A, (b) 52 W. 13. 13.9 A
Chapter 8Self-assessment test
- ~-, second. 7. L/R. 8. 10 ms. 9. 103 A s -1. 10. 2 A. 11. Exponential rise. 12. Exponential
decay. 13. The resistor. 14. The resistor. 15. 500 pos. 16. 5 ms. 17. 0.362 A. 18. 50 txs.
Problems
L (a) 10 A s -1, (b) 0.948 A, (c) 1 s, (d) 10 A, (e) 5 s. 2. (a) 526.6 f~, 2.11 H; (b) 94.97 As -1.
- (a) 6.97 A; (b) 1 s. 4. 2.72 MI'I. 5. 2.89 MI'I. 6. 17 ms. 7. (b) Vc = 1011 - exp (-1000t)],
i = 0.511 + exp (-1000t). 8. (a) An exponential growth reaching 20 V after 5z
(z = 2.55 ms); (b) an exponential growth reaching 17.2 V after 5 ms and subsequently
decaying exponentially to zero after a further 12.75 ms; (c) as for (b) but repeating 7.25 ms
after becoming zero. 9. (a) An exponential decay starting at 15 V and falling to zero in
15 I~s; (b) an exponential decay starting at 15 V and falling to 2.8 V after 5 ~s at which time
the pulse is removed, then instantaneously reversing to -12.2 V and rising exponentially to
reach zero after a further 15 txs; (c) as for (b) but repeating 5 ~s after becoming zero; (d)
an exponential decay starting at 15 V and falling to 2.8 V after 5 I~s, then an instantaneous
change to -12.2 V and an exponential rise towards zero reaching -2.3 V after a further
5 Ixs; another instantaneous change to + 12.7 V, followed by an exponential decay to 2.39 V
after a further 5 ~s. This continues with each successive positive voltage becoming smaller