英文题目
1. Superposition Theorem is only applicable for determining branch or element voltage and
current of a circuit, not power.
(a) True
(b) False
2. Superposition Theorem can be applied in circuits where the resistance of a component changes
with voltage or current.
(a) True
(b) False
3. One prerequisite for Superposition Theorem is that all components must be "bilateral," meaning
that they behave the same with electrons flowing either direction through them.
(a) True
(b) False
4. The __________________________ states that a circuit can be analyzed with only one source
of power at a time, the corresponding component voltages and currents algebraically added to find
out what they'll do with all power sources in effect.
(a) Ohm's Law
(b) Millman's Theorem
(c) Thevenin's Theorem
(d) Superposition Theorem
5. The _______________________________ states that it is possible to simplify any linear circuit,
no matter how complex, to an equivalent circuit with just a single voltage source and series
resistance connected to a load.
(a) Norton's Theorem
(b) Superposition Theorem
(c) Thevenin's Theorem
(d) Millman's Theorem
6. The ______________________________ states that it is possible to simplify any linear circuit,
no matter how complex, to an equivalent circuit with just a single current source and parallel
resistance connected to a load.
(a) Norton's Theorem
(b) Branch current method
(c) Thevenin's Theorem
(d) Mesh current method
7. When we convert a circuit into a Thevenin equivalent circuit or Norton equivalent circuit, the
Thevenin series resistor and Norton parallel resistor are ________________.
(a) undetermined
(b) different
(c) irrelevant
(d) identical
8. In a resistor-capacitor charging circuit, where capacitor is completely discharged initially,
capacitor voltage goes from nothing to full source voltage while current goes from maximum to
zero, both variables changing most rapidly at first, approaching their final values slower and
slower as time goes on.
(a) True
(b) False
9. A completely discharged capacitor initially acts as a(n) ______________ when faced with the
sudden application of voltage. After charging fully to that level of voltage, it acts as a(n)
_____________.
(a) open circuit…………short circuit
(b) short circuit…………short circuit
(c) open circuit…………open circuit
(d) short circuit…………open circuit
10. A completely "discharged" inductor (no current through it) initially acts as a(n)
_____________ when faced with the sudden application of voltage. After "charging" fully to the
final level of current, it acts as a(n) _______________________.
(a) open circuit…………short circuit
(b) open circuit…………open circuit
(c) short circuit…………short circuit
(d) short circuit…………open circuit
11. Consider a circuit with a time varying voltage source, a cap
and a resistor as shown on the right. Assume that uC(0)=0, and
0
u s (t )  
1
t0
t0
+
us(t)
-
R
+
C
uc(t)
-
Which of the following statements is correct?
(a) When t=0+, the voltage on the capacitor equals 1V and remains unchanged afterwards.
(b) When t=0+, the voltage on the capacitor equals 0V and remains unchanged afterwards.
(c) When t=0+, the voltage on the capacitor equals 1V and decreases rapidly. But this rate of
decrease slows down afterwards, and the voltage approaches 0V asymptotically.
(d) When t=0+, the voltage on the capacitor equals 0V and increases rapidly. But this rate of
increase slows down afterwards, and the voltage approaches 1V asymptotically.
12. Consider a circuit with a time varying voltage source, a cap
and a resistor as shown on the right. Assume that uC(0)=0, and
0
u s (t )  
1
t0
t0
+
us(t)
-
R
+
C
uc(t)
-
When does the voltage on the capacitor change at a maximum rate?
(a) t=0+
(b) t=, where =RC
(c) t=2
(d) t=
13. Consider a circuit with a time varying current source and a cap
+
is(t)
C
uc(t)
-
as shown on the right. Assuming that the cap has no charge across it initially, and
0
is (t )  
1
t0
t0
The capacitor voltage ________________________.
(a) increases exponentially with time, starting at uC(0)= 0
(b) increases exponentially with time, starting at uC(0)= 1
(c) increases linearly with time, starting at uC(0)= 1
(d) increases linearly with time, starting at uC(0)= 0
14. Consider a circuit with a time varying voltage source and an
+
inductor as shown on the right. Assuming that the initial current
us(t)
through the inductor for t < 0 is zero, and
-
0
u s (t )  
1
iL(t)
L
t0
t0
The inductor current ________________________.
(a) increases exponentially with time, starting at iL(0)= 0
(b) increases asymptotically with time, starting at iL(0)= 0
(c) increases linearly with time, starting at iL(0)= 0
(d) increases linearly with time, starting at iL(0)= 1
15. Consider a circuit with a time varying voltage source, an
inductor and a resistor as shown on the right. Assuming that the
+
us(t)
initial current through the inductor for t < 0 is zero, and
0
u s (t )  
1
iL(t)
R
L
-
t0
t0
Which of the following statements is correct?
(a) When t=0+, the current on the inductor equals 0A and increases rapidly. But this rate of
increase slows down afterwards, and the current approaches 1/R (A) asymptotically.
(b) When t=0+, the current on the inductor equals 0A and remains unchanged afterwards.
(c) When t=0+, the current on the inductor equals 1/R (A) and decreases rapidly. But this rate of
decrease slows down afterwards, and the current approaches 0A asymptotically.
(d) When t=0+, the current on the inductor equals 0A and approaches 1/R (A) linearly.
16. Consider a circuit with a time varying voltage source, an
+
inductor and a resistor as shown on the right. Assuming that the
us(t)
initial current through the inductor for t < 0 is zero, and
-
0
u s (t )  
1
iL(t)
R
L
t0
t0
When does the current iL(t) change at a maximum rate?
(a) t=
(b) t=, where =L/R
(c) t=2
(d) t=0+
17. Consider a circuit with a DC voltage source, a capacitor, a
switch and a resistor as shown on the right. Assuming that
+
R
uS(t)=5V, uC(0)=7V, and the switch remains opened until t=0, the us(t)
C
switch closes. Which one of the following is correct?
(a) There is no current in the circuit.
(b) The current flows through resistor from right to left and decreases to 0 exponentially.
(c) The current flows through resistor from right to left and decreases to 0 linearly.
(d) The current flows through resistor from left to right and decreases to 0 linearly.
+
uc(t)
-
18. Consider a circuit with a DC voltage source, a capacitor, a
switch and a resistor as shown on the right. Assuming that
+
R
+
C
uc(t)
uS(t)=3V, uC(0)=5V, and the switch remains opened until t=0, the us(t)
switch closes. Which one of the following is correct?
(a) The capacitor voltage uC(t) equals 3V immediately without
transience.
(b) The capacitor charges from the beginning uC(0+)=3V. Then uC(t) increases exponentially to its
final value uC()=5V.
(c) The capacitor discharges from the beginning uC(0+)=5V. Then uC(t) decreases linearly to its
final value uC()=3V.
(d) The capacitor discharges from the beginning uC(0+)=5V. Then uC(t) decreases exponentially to
its final value uC()=3V.
19. The circuit is shown on the right. For t<0, switch
K1 remains opened and K2 closed. K1 closes and K2
K1
K2
R
iL(t)
+
uL(t)
–
+
opens at t=0. Assuming U0/RIS, consider the current Uo
L
through the inductor,
(a) iL(t) varies from the beginning iL(0+)=IS, to its final
value U0/R exponentially.
(b) iL(t) varies from the beginning iL(0+)=IS, to its final value U0/R linearly.
(c) iL(t) varies from the beginning iL(0+)= U0/R, to its final value IS asymptotically.
(d) iL(t) equals U0/R immediately without transience.
20. The circuit is shown on the right. For t<0, switch
K1 remains opened and K2 closed. K1 closes and K2
K1
K2
R
+
opens at t=0. Assuming U0/RIS, consider the voltage Uo
across the inductor,
(a) uL(t) equals 0 immediately without transience.
(b) uL(t) varies from a non-zero value linearly to 0.
(c) uL(t) varies from a non-zero value exponentially to 0.
(d) uL(t) equals to U0.
IS
L
iL(t)
+
uL(t)
–
IS
21. The corresponding Phasor representation of signal u (t )  2 cos t is ________________.


(a) U  2


(b) U  2 j
(d) U  2
(c) U  2  j 2

22. Express the Phasor U  3120 as sinusoidal or cosinoidal signal.
(a) u (t )  3 cos(t  30)
(b) u (t )  3 sin( t  60)
(c) u (t )  3 cos(t  120)
(d) None of the above
(a)  
(b)  
(c)

(d)  
jL

23. Consider the circuit shown on the right. Under what
condition does the circuit display a resonance phenomenon?
I
1
+
RLC
–
R

US
1/(jC)
R
LC
1
L / R  RC
1
LC
–j7Ω
4Ω 1
24. Consider the circuit shown on the right. Which of the
following nodal equations for node 1 is correct?



IS


 1
U1
1 
3I1
U 1  I S 
(a) 
, where I 1 

j4
j7
 j 4  j7 




 1
U1
1 
3I1
U 1  I S 
(b) 
, where I 1 

j4
 j7
 j 4  j7 




1 1
U1
1 
3I1
U 1  I S 
(c)  
, where I 1 

 j7
 j7
 4 j 4  j7 


I1
I2
+
+
j4Ω
–

3 I1
–




1 1
U1
1 
3I1
U 1  I S 
(d)  
, where I 1 

j4
 j7
 4 j 4  j7 
–j3Ω
5Ω
25. Consider a circuit shown on the right which consists of



two meshes with current denoted as I 1 and I 2 , noticing



that branch current through inductor is I 3  I 1  I 2 ,

+

I3
I1
US
–

+
I2
j7Ω
–
which of the following mesh equations is correct?





















(a) (5  j 7) I 1  j 7 I 2  U s ,  j 7 I 1  ( j 7  j 3) I 2  4 I 3

(b) (5  j 7) I 1  j 7 I 2  U s ,  j 7 I 1  ( j 7  j 3) I 2  4 I 3

(c) (5  j 7) I 1  j 7 I 2  U s ,  j 7 I 1  ( j 7  j 3) I 2  4 I 3

(d) (5  j 7) I 1  j 7 I 2  U s ,  j 7 I 1  ( j 7  j 3) I 2  4 I 3
L
26. Consider the circuit shown on the right. A sinusoidal
a
A0
signal is applied to port ab. Three AC Ammeters A0, A1 and
A2 are used to measure RMS value of current of the
~
sinusoidal waveform. Assuming that the indications of A1 and
b
A2 are 4A, then the indication of A0 should be______(A).
(a) 8
(b) 4 3
(c) 4 2
(d) 4

4 I3
A1
R
A2