UMD
ECE2006
HW8: Due Wednesday, November 23, 2005
Chapter 8, Problem 1.
For the circuit in Fig. 8.62, find:
(a) i(0+) and v(0+),
(b) di(0+)/dt and dv(0+)/dt,
(c) i() and v().
Figure 8.62
Chapter 8, Solution 1.
(a)
At t = 0+, i(0+) = i(0-) = 2A, v(0+) = v(0-) = 12V
di(0+)/dt = -8/2 = -4 A/s
dv(0+)/dt = -2/0.4 = -5 V/s
i() = 0 A, v() = 0 V
Chapter 8, Problem 2.
In the circuit of Fig. 8.63, determine:
(a) iR(0+), iL(0+), and iC(0+),
(b) diR(0+)/dt, diL(0+)/dt, and diC(0+)/dt,
(c) iR(), iL(), and iC().
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S.Norr
UMD
ECE2006
HW8: Due Wednesday, November 23, 2005
S.Norr
Figure 8.63
Chapter 8, Problem 15.
The responses of a series RLC circuit are
vC(t) = 30 - 10e-20t + 30e-10t V
iL(t) = 40e-20t - 60e-10t mA
where vC and iL are the capacitor voltage and inductor current, respectively.
Determine the values of R, L, and C.
Chapter 8, Solution 15.
R = 750 Ohms, L = 25 H, C = 200 uF
Chapter 8, Problem 18.
Find the voltage across the capacitor as a function of time for t > 0 for the circuit
in Fig. 8.72. Assume steady-state conditions exist at t = 0-.
Figure 8.72
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UMD
ECE2006
HW8: Due Wednesday, November 23, 2005
S.Norr
Chapter 8, Problem 23.
For the network in Fig. 8.76, what value of C is needed to make the response
underdamped with unity damping factor ( = 1)?
Figure 8.76
Chapter 8, Solution 23.
Co = C + 10 mF = 50 mF or 40 mF
Chapter 8, Problem 33.
Find v(t) for t > 0 in the circuit in Fig. 8.81.
Figure 8.81
Chapter 8, Solution 33.
v(t) = {20 – 10e-0.05t} V
Chapter 8, Problem 45.
In the circuit of Fig. 8.92, find v(t) and i(t) for t > 0. Assume v(0) = 0 V and
i(0) = 1 A.
Figure 8.92
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UMD
ECE2006
HW8: Due Wednesday, November 23, 2005
Chapter 8, Solution 45.
i(t) = {4 – [(3cos1.323t + 1.134sin1.323t)e-0.5t]} A
v(t) = 4.53sin(1.323t)e-0.5t Volts
Chapter 8, Problem 53.
Derive the second-order differential equation for vo in the circuit
of Fig. 8.99.
Figure 8.99
Chapter 8, Solution 53.
Hence,
(R1C1R2C2)(d2vo/dt2) + (R1C1 + R2C2 +R1C2)(dvo/dt) = R1C1(dvs/dt)
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S.Norr