P r o b l e m s ------ ( 149
Figure P 4.3-7
P 4.3-8 The circuit shown in Figure P 4.3-8 has two inputs, v,
and v2, and one output, vQ. The output is related to the input by
the equation
v0 = tfvi 4- bv2
Figure P 4.3-10
*P 4.3-11 Determine the values of the node voltages of the
circuit shown in Figure P 4.3-11.
3A
where a and b are constants that depend on Ru R2, and R3.
(a) Determine the values of the coefficients a and b when
R\ = 1 0 f i ,/?2 —40 0 , and R3 = 8 0 .
(b) Determine the values of the coefficients a and b when
R\ = R2 and R$ = R \ 11/?2-
P 4.3-12 Determine the values of the node voltages of the
circuit shown in Figure P 4.3-12.
Figure P 4.3-8
P 4.2-9 Determine the values of the node voltages of the
circuit shown in Figure P 4.3-9.
5V
r-O 80
v\ — V W
( j 1.25 A
20 Q
-V A ---12 n
“AA/V— 1^4
40 O
1 )1 5 V
?
Figure P 4 3-9
P 4.3-10 Figure P 4.3-10 shows a measurement made in the
laboratory. Vour lab partner forgot to record the values of R „
* 2, and
He thtnks that the two resistors were 10-kfl
resistors and the other was a 5-kfl resistor. Is this possible?
Which resistor is the 5-kn resistor?
Figure P
_
.
Section 4.4 Node V o ltage Analysis w ith Dependent
Sources
D a a 1 tu
u
j
t™
,
P*
The V0'tageS V“’. ‘V and V' m F,gure P 4 4 ‘ 1 are the
node vol|aees correspond.ng to nodes a, b, and c. The values of
6
voltages are:
v, = 8.667 V, vt, = 2 V. and v-c = 10 V
M e th o d s o f A n a ly s is o f R e s is tiv e C irc u its
P 4.6-3 Find v2 for the circuit shown in Figure P 4.6-3.
Answer: v2 = 2 V
+ v2 ~
60 ft
- ^ W \ ,-----------------------f----W V
20 ft
05 A
I110
U VV
L
Figure P 4.5-5
P 4.5-6 Simplify the circuit shown in Figure P 4.5-6 by
replacing series and parallel resistors by equivalent resistors.
Next, analyze the simplified circuit by writing and solving
mesh equations.
30af
G
?
G
y
C
v
r
n
Figure P 4.6-3
P 4.6-4 Find vc for the circuit show™ in Figure P 4.6-4.
(a) Determine the power supplied by each source,
(b) Determine the power absorbed by the 30-0 resistor.
P 4.6-5 Determine the value of the voltage measured by the
voltmeter in Figure P 4.6-5.
Section 4.6 Mesh Current Analysis w ith C urrent
and V oltag e Sources
Answer: 8 V
P 4.6-1 Find z'b for the circuit shown in Figure P 4.6-1.
Answer: zb = 0.6 A
10 V
0.5 A 0
50 f t
25 f t
Figure P 4.6-1
P 4.6-2
P 4.6-6 Determine the value of the current measured by the
ammeter in Figure P 4.6-6.
Find vc for the circuit shown in Figure P 4.6-2.
Hint: Write and solve a single mesh equation.
Answer: vc — 15 V
7 5 ft
Figure P 4.6-2
1 0 0 ft
P 4.6-7 The currents i lt z2 and z3 in Figure P 4.6-7 are the
mesh currents. Determine the value of the resistance R.
P r o b l e m s ------ ( 197
Hint: Figure P 5.3-19/) shows the circuit after the ideal
voltmeter has been replaced by the equivalent open circuit
and a label has been added to indicate the voltage measured
by the voltmeter, vm.
Answer: v„
Vm = 3 (,33 + 7(33 + 3)'
3 ) 5)
= 5 - 6 = -IV
” •3 + (3 + 3)
Answer:
= —12 V and Rt = 16 ft
10 ft
8 ft
18
Figure P 5.4-2
P 5.4-3 The circuit shown in Figure P 5.4-36 is the Thevenin
equivalent circuit of the circuit shown in Figure P 5.4-3a. Find the
value of the open-circuit voltage, Vqc, and Thevenin resistance, Rt.
Answer: voc = 2W and Rt = 4 fl
L
f
J
1
L
t)5 A
I 3n
r.
12 V
18 V
-o
+
I
"m <
3 ft ~ 1
3ft
(b)
Figure P 5.3-19 (a) A circuit containing two independent
sources. (b) The circuit after the ideal voltmeter has been
replaced by the equivalent open circuit and a label has been
added to indicate the voltage measured by the voltmeter, vm.
(a)
Figure P 5.4-3
P 5.4-4 Find the Thevenin equivalent circuit for the circuit
shown in Figure P 5.4-4.
12 ft
--------- V A --------6ft
10 ft
— w v-AAAr-
Section 5.4 Thevenin's Theorem
P 5.4-1 Determine values of Rt and
that cause the circuit
shown in Figure P 5.4-16 to be the Thevenin equivalent circuit
of the circuit in Figure P 5.4-la.
Hint: Use source transformations and equivalent resistances
to reduce the circuit in Figure P 5.4-1 a until it is the circuit in
Figure P 5.4-16.
Answer: Rt = 5 ft and voc = 2 V
18 V
*3 ft
Figure P 5.4-4
P 5.4-5 Find the Thevenin equivalent circuit for the circuit
shown in Figure P 5.4-5.
Answer: voc = - 2 V and R{ = - 8 / 3 ft
0.75i;,
(a)
Figure P 5.4-1
P 5.4-2 The circuit shown in Figure P 5.4-26 is the Thevenin
equivalent circuit of the circuit shown in Figure P 5 .4-2a. Find
the value of the open-circuit voltage, v^, and Thevenin
resistance, Rx.
Figure P 5.4-5