Basic Circuit Theory Chpter6 Problems 7 For the circuit shown in Fig. 6-15, find vc(t) and i,(t) 5u()A+ 5HFT C 6-15Fo 8 The strength of the current source in Fig. 6-16 is suddenly increased from 10A to 20A at t=0 finds(0 ),Vs(0),Vs(oo), and vs(t) 10A3g IH 80m Fig 6-16 For prob. 8. 9 A source-free parallel RLC circuit contains an inductor for which the product @ L is 10Q2 Ifs,=-6s and s2=-8s, find R, L, and C. 10. With reference to the circuit of Fig 6-17, let i(0)=40A and v(0)=40V. If L=12.5H,R= 0.1Q2, and C=0.2F, find v(t) Fig. 6-17 For prob. 10 Reference answers to Selected Problems 1:(a)200e--100eV(t>0);(b)-100e-+200eV(t>0) 2:(a)5/6H(b)v(t)=210e-2-190eV(t>0) 3:200(e 4:(a)2592;(b)(100+625e-0v(t>0) 5:-9992V 6:20+250e-100-150N,A 7:(a)-5 25--200800 (t>0)(b)-2+2(4e-200-00)(0) 8:(a)20V;(b)50V(c)40V;(d40e-23(0cos25t24sin2.5V(>0) 9:4959,1443H,1443mF 0:(a)-20e-+60eV(t>0) DaLian Maritime UniversityBasic Circuit Theory Chpter6 Problems 7 For the circuit shown in Fig.6-15, find v (t) and i (t). C L - + A 25 Ω L i 25µF C v 3 − 5u(t) 2.5mH 8 The strength of the current source in Fig.6-16 is suddenly increased from 10A to 20A at t = 0, find v (0 ), v (0 ), v ( ), and v (t). S − S + S ∞ S Fig. 6-15 For prob.7. - + 1H s v 3 Ω 2 Ω 80mF 10 A Fig. 6-16 For prob.8. 9 A source-free parallel RLC circuit contains an inductor for which the product ω 0 L is 10 . If s 1= - 6s and s 2 = - 8s , find R, L, and C. Ω −1 −1 10. With reference to the circuit of Fig.6-17, let i(0) = 40A and v(0) = 40V. If L = 12.5H, R = 0.1Ω , and C = 0.2F, find v(t) R L C C R i i i v − + Fig. 6-17 For prob.10. Reference Answers to Selected Problems 1: (a) 200e -100e V (t >0); (b) -100e +200e V ( t > 0). −2t −8t −2t −8t 2: (a) 5/6 H; (b) v(t)=210e -190e V (t > 0). −4t −6t 3: 200(e - e ). −5000t −15000t 4: (a) 25Ω ; (b) (100+6.25t) e V (t > 0). −5000t 5: -9992V. 6: 20+250(e -e )V, −100t −150t 24 1 (3e -2 e )A. −150t −100t 7: (a) –50+ 3 25 (16e -e )V (t >0); (b) –2+ −2000t −8000t 3 5 (4 e -e ) (t >0). −2000t −8000t 8: (a) 20V; (b) 50V;(c) 40V; (d)40+e (10 cos 2.5t+24 sin 2.5t)V (t>0). −2.5t 9: 4.95Ω , 1.443H, 14.43 mF. 10: (a) –20e +60e V (t >0). −10t −40t DaLian Maritime University 2