2260
HOMEWORK #2 probs 1 and 2 solution
F 10
EX:
L
R2
ig
R1
i
C
t=0
After being closed for a long time, the switch opens at t = 0.
L = 2.5 nH
a)
di( t )
dt t = 0 +
Find the numerical values of L and C for the above circuit, given the following
information
2260
F 09
HOMEWORK #10 prob 3 solution
EX:
j4
zL
N1
1.5
N2
1
jC
ideal
Given = 300rad/s and N 1/N2 = 10, find the value of C that makes zL=1.5.
Note that zLis the equivalent impedance of the entire circuit.
2260
F 09
HOMEWORK #9 probs 1 and 2 solution
EX:
t=0
L=
1
H
4
R1 =
150
R2
C=
1.2 mF
Vs = +
30 V
After being closed for a long time, the switch opens at t = 0.
The inductance in the above circuit acts as the coil (magnet) for a relay. The relay is
design
2260
HOMEWORK #9
F 09
1.
t=0
L=
1
H
4
R1 =
150
R2
C=
1.2 mF
Vs = +
30 V
After being closed for a long time, the switch opens at t = 0.
The inductance in the above circuit acts as the coil (magnet) for a relay. The
relay is designed to stay energized for
2260
F 09
HOMEWORK #8 prob 5 solution
EX:
3
Vs =
N1
+
420 V
I2
4
N2
Given N1/N2=1/6, calculate the phasor current, I2, flowing upward in the bottom
coil of the transformer. Note: the transformer is ideal.
SOL'N:
2260
HOMEWORK #8
F 09
1.
a
+
j120
6000 Arms
Vrms
120
j30
b
a)
Calculate the value of rms voltage, Vrms, across the circuit to the right of
terminals a and b.
b)
Calculate the average power, P, and the reactive power, Q, for the circuit to
the right of
2260
F 09
HOMEWORK #8 prob 1 solution
EX:
a
+
j120
6000 Arms
Vrms
120
j30
b
a)
Calculate the value of rms voltage, V rms, across the circuit to the right of
terminals a and b.
b)
Calculate the average power, P, and the reactive power, Q, for the circui
2260
F 09
HOMEWORK #8 prob 4 solution
EX:
jM = j10
I1
Is = 390 A
36
jL1
= j17
jL2
= j 20
j30
Calculate the numerical value of phasor current I1 for the above circuit. Note: the
transformer is linear.
SOL'N:
2260
HOMEWORK #8
F 09
1.
a
+
j120
6000 Arms
Vrms
120
j30
b
a)
Calculate the value of rms voltage, Vrms, across the circuit to the right of
terminals a and b.
b)
Calculate the average power, P, and the reactive power, Q, for the circuit to
the right of
2260
F 09
HOMEWORK #7 probs 4 and 5 solution
EX: Va'n a' a A
zgY
zline
zL
Vb'n n b' zgY b zline
B
zL
zL
zgY Vc'n c'
c
zline
C
Vga'n=145.50V Vgb'n=145.5120V
zgY= 0.1 resistor in series with 265.3 H inductor zline= 265.3 H inductor
Vgc'n=145.5+120V zL= 0.6
2260
F 09
HOMEWORK #6 probs 2 and 3 solutions
EX:
C = 200 mF
t v g ( t ) = 6V + 3e cos(2t) u(t)V +
L = 200 mH
+
R = 1.2
v o (t)
Note: The 6 V in the vg(t) source is always on. a) b) c) d) Write the Laplace transform, Vg(s), of vg(t). Draw the s -domain
2260
F 09
HOMEWORK #10 probs 4 and 5 solution
EX:
VgYa'n
+
a'
zgY
a
zline
A
zL
VgYb'n
+
n
b'
zgY
b
zline
B
zL
zL
VgYc'n
+
c'
zgY
c
zline
C
VgYa'n=1700V
zgY=
0.1 + j0.1
VgYb'n=170120V
zline=
1.1 + j1.6
VgYc'n=170+120V
zL=
1.5
a)
For the above 3-phase balan
2260
C OURSE P ROCEDURE*
The learning system used in ECE 2260 has been designed on the basis of the
principles of learning1
- 3.
I won't give you a lengthy description of those principles here,
but let me state informally two of them that are very importa
HOMEWORK #2 prob 3 solution
2260
F 10
EX:
i1
L1
R1
+
v1
C
R2
L2
i2
vg +
At t = 0, vg(t) switches instantly from vo to vo.
a)
Write the state-variable equations for the circuit in terms of the state vector:
i1
r
x = i2
v1
Evaluate the state vector at t
2260
HOMEWORK #2
F 10
1.
L
R2
ig
R1
i
C
t=0
After being closed for a long time, the switch opens at t = 0.
Give expressions for the following in terms of no more than ig, R1, R2 L, and C:
i( t = 0+ )
di( t )
dt t = 0 +
and
the numerical values of L and C
HOMEWORK #1 prob 4 solution
2260
F 10
EX:
After being closed for a long time, the switch opens at t = 0.
L = 1 H
C = 16 F
R1 = 0.15
R2 = 0.1
If is = 30 mA, f ind i(t) for t > 0.
SOL'N:
We may perform the following initial steps in any order:
1)
Find cha
HOMEWORK #1 prob 3 solution
2260
F 10
EX:
After being closed for a long time, the switch opens at t = 0.
L = 10 nH
C = 250 nF
R1 = 0.1
R2 = 0.025
If vs = 10 V, find v(t) for t > 0.
SOL'N:
We may perform the following initial steps in any order:
1)
Find
HOMEWORK #1 prob 2 solution
2260
F 10
EX:
L
R
C
L = 100 H
C = 400 F
The above circuit may be used to generate a note for an electronic synthesizer.
a)
Find the value of R that will make the circuit oscillate at 440 Hz, (corresponding
to an 'A' note). Reme
HOMEWORK #1 prob 1 solution
2260
F 10
EX:
L
C
L = 2.5 nH
R
C = 1.6 nF
R = 0.625
a)
Find the characteristic roots, s1 and s2, for the above circuit.
b)
Is the circuit over-damped, critically-damped, or under-damped? Explain your
answer.
c)
If the L and C
2260
F 09
HOMEWORK #9 probs 3-5 solution
EX:
1 A t < 0
is ( t ) =
1A t 0
R2
C=
1
F
6
R1
+
+
L = 9.6 mH
+
v1(t)
v0(t)
Find a symbolic expression for the Laplace-transformed output, Vo(s), in terms of not
more than R1,R2,L,C, and values of sources or const
2260
HOMEWORK #1
F 10
1.
L
C
L = 2.5 nH
R
C = 1.6 nF
R = 0.625
a)
Find the characteristic roots, s1 and s2, for the above circuit.
b)
Is the circuit over-damped, critically-damped, or under-damped? Explain
your answer.
c)
If the L and C values in the cir
2260
F 09
HOMEWORK #10 probs 1 and 2 solution
EX:
R = 100
+
+
C1
vi
vo
C2
L = 5 mH
v i (t)
4V
0
T
4
T
2
3T
4
T
t
T = one period of vi(t) = 2 ms
4 cos( 0t) V
vi ( t ) =
4V
0 < t T /2
T /2 < t T
a)
Find values of C 10 and C20 for the above filter circuit
2260
F 10
N. Cotter
Instructor:
Required Text:
Required Packet:
(or available on web)
Required Packet:
(or available on web)
Recommended Text:
Recommended Text:
Homework:
Last day to drop:
Last day to withdraw:
Cheating:
Equal Access:
C OURSE I NFORMATION
2260
HOMEWORK #10
F 09
1.
R = 100
+
+
C1
vi
vo
C2
L = 5 mH
v i (t)
4V
0
T
4
T
2
3T
4
T
t
T = one period of vi(t) = 2 ms
4 cos( 0t) V
0 < t T /2
vi ( t ) =
4V
T /2 < t T
Find values of C 10 and C 20 for the above filter circuit such that the
magnitude o
2260
F 09
HOMEWORK #7
1.
a
C= 0.5 nF
1.337 mA iL(t) L= 1.1 mH R= 500
b
Note: =2Mr/s. Do the following for the impedance to the right of the a, b terminals: a) Calculate complex power S = P + jQ. b) Calculate average (or DC) power. c) Calculate maximum in
2260
F 09
HOMEWORK #7 prob 1 solution
EX:
a C= 0.5 nF 1.337 mA iL(t) L= 1.1 mH R= 500
b
Note: =2Mr/s. Do the following for the impedance to the right of the a, b terminals: a) Calculate complex power S = P + jQ. b) Calculate average (or DC) power. c) Cal
2260
F 09
HOMEWORK #7 prob 3 solution
EX: a A
zline
zLY
zg
Vgca zg
Vgab b zline B zLY N
zg
Vgbc c Vgab=1230V Vgbc=123+120V zline zLY C
zg= 0.93+j1.2 zline= j0.61
Vgca=123120V zLY= 0.4j0.3 a) Draw the single phase equivalent circuit. b) Calculate Van. SOL'
2260
F 09
HOMEWORK #5 prob 1d solution
EX:
Find the Laplace transform of the following waveform:
f ( t ) = e5t [2 cos(12 t ) + 7 sin(12 t )]
SOL'N:
The Laplace transform is linear, meaning that we may multiply basic transform pairs by constants to obtain
2260
F 09
HOMEWORK #5 prob 1b solution
EX:
Find the Laplace transform of the following waveform: d 4 t t2 e cos( 3t ) dt
[
]
SOL'N:
We start on the inside (of this layered onion) and apply identities to work our way out to the time-domain form given. The