220 Practical MATLAB® Applications for Engineers
FIGURE 2.131
Network of P.2.39.
V = 120 V−R
C = 1/27 FR 1 = 10 ΩL = 9 HSwitch opens at t = 0P.2.37 For each of the circuits shown in Figure 2.129, evaluate and plot the expression for
i(t) for 0 < t ≤ 5 τ, if the switch is moved from position 1 to position 2 at t = 0 after
having been in position 1 for a long time.
P.2.38 Choose appropriate values for R to obtain the three circuit responses: overdamped,
critical, and underdamped. Write the differential equation, and use MATLAB to
obtain the three second-order solutions, as well as their respective plots of the
source-free series RLC circuit diagram shown in Figure 2.130, for t ≥ 0.
P.2.39 Obtain and plot the transient response of the source-free RLC circuit shown in
Figure 2.131—overdamped, critical, and underdamped—by choosing appropriate
values for R (for t > 0).
P.2.40 Steady-state conditions exist for t ≤ 0 in the circuit of Figure 2.132 (while the volt-
age source is connected to the circuit). At t = 0 +, the switch moves downward.
Obtain the transient current responses and the respective plots for each of the loop
currents.
FIGURE 2.130
Network of P.2.38.
V = 100 V+−RC = 1/16 FR 1 = 10 ΩL = 4 HSwitch opens at t = 0