EE 350
PROBLEM SET 1
DUE: 2 September 2008
Reading assignment: Lathi Chapter 1 and Background, Sections B.2 and B.3, and the MATLAB primer (available on the EE
350 web page).
Recitation sections will meet the week of August 25.
Problems 1 through 3 are a review of material covered in EE 210 and require you to obtain an ordinary diﬀerential equation
and initial conditions for a simple circuit.
Problem 1:
(16 points)
Consider the RL circuit in Figure 1. You may assume that the switch has been closed long enough for the voltages and
currents to reach steadystate values. At time
t
= 0 the switch is opened.
t = 0
+

+

v(t)
3 H
5 Ω
i(t)
10 Ω
10 Ω
40 V
Figure 1: The switch in the RL circuit is opened at time
t
=0
.
1. (4 points) Find the voltage
v
(0

) and the current
i
(0

) just before the switch is opened.
2. (4 points) Find the voltage
v
(0
+
) and the current
i
(0
+
) immediately after the switch is opened.
3. (2 points) Find the voltage
v
(
∞
) and the current
i
(
∞
) after the switch has been opened for a very long time.
4. (6 points) Find a diﬀerential equation that describes the response of the voltage
v
(
t
) for
t
≥
0.
Problem 2:
(16 points)
In the circuit shown in Figure 2, the switch was opened for a long time and then it was closed at
t
.
30 μ
F
10
Ω
k
5
Ω
k
+

i(t)
v(t)
+

t = 0
12 V
Figure 2: The switch in the RC circuit is closed at time
t
.
1. (4 points) Find the voltage
v
(0

) and the current
i
(0

) just before the switch is closed.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '07
 SCHIANO,JEFFREYLDAS,ARNAB
 RC circuit, RL circuit

Click to edit the document details