Explore topic-wise MCQs in Electrical Engineering.

This section includes 62 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

1.

In an ac circuit, power to the load peaks at the frequency at which the load impedance is the complex conjugate of the output impedance.

A. True
B. False
Answer» B. False
Discussion
2.

In order to get maximum power transfer from a capacitive source, the load must have an impedance that is the complex conjugate of the source impedance.

A. True
B. False
Answer» B. False
Discussion
3.

Thevenin's theorem provides a method for the reduction of any ac circuit to an equivalent form consisting of an equivalent current source in parallel with an equivalent impedance.

A. True
B. False
Answer» C.
Discussion
4.

The superposition theorem is useful for the analysis of single-source circuits.

A. True
B. False
Answer» C.
Discussion
5.

Like Thevenin's theorem, Norton's theorem provides a method of reducing a more complex circuit to a simpler, more manageable form for analysis.

A. True
B. False
Answer» B. False
Discussion
6.

Norton's theorem provides a method for the reduction of any ac circuit to an equivalent form consisting of an equivalent voltage source in series with an equivalent impedance.

A. True
B. False
Answer» C.
Discussion
7.

A Thevenin ac equivalent circuit always consists of an equivalent ac voltage source and an equivalent capacitance.

A. True
B. False
Answer» C.
Discussion
8.

The superposition theorem is useful for circuit analysis only in ac circuits.

A. True
B. False
Answer» C.
Discussion
9.

Referring to the given circuit,

A. must be in parallel with
B. must be placed in parallel with
C. must have a reactance equal to
D. has no effect on the result
Answer» E.
Discussion
10.

Referring to the given circuit, how much power, in watts, is delivered to the speaker at the determined frequency if = 4.5 V?

A. 226 mW
B. 2.26 mW
C. 4.24 mW
D. 424 mW
Answer» E.
Discussion
11.

Referring to the given figure, determine ZTH as seen by RL if R1 is changed to 3.3 k.

A. 1488–70.7°
B. 3859 –31.2°
C. 5180 –50.5°
D. 1828–50.2°
Answer» E.
Discussion
12.

Referring to the given circuit, what is VTH if VS = 120° V?

A. 4.6938.7° V
B. 9.3838.7° V
C. 120° V
D. 60° V
Answer» C. 120° V
Discussion
13.

Determine VTH if R1 is changed to 3.3 k.

A. 0.57416.7° V
B. 4.6316.7° V
C. 4.6339.5° V
D. 0.46339.5° V
Answer» D. 0.46339.5° V
Discussion
14.

Referring to the given circuit, find ZTH for the part of the circuit that is external to RL.

A. 29 ∠21.4° Ω
B. 3.7 ∠68.6° Ω
C. 3.7 ∠21.4° Ω
D. 2.9 ∠68.6° Ω
Answer» C. 3.7 ∠21.4° Ω
Discussion
15.

Referring to the given figure, determine ZTH as seen by RL if R1 is changed to 3.3 kΩ.

A. 488 ∠-70.7° Ω
B. 859 ∠-31.2° Ω
C. 180 ∠-50.5° Ω
D. 828 ∠-50.2° Ω
Answer» E.
Discussion
16.

Determine VTH if R1 is changed to 3.3 kΩ.

A. .574 ∠16.7° V
B. .63 ∠16.7° V
C. .63 ∠39.5° V
D. .463 ∠39.5° V
Answer» D. .463 ∠39.5° V
Discussion
17.

Referring to the given circuit, what is ZTH if R1 is changed to 220 Ω?

A. 25 ∠12.1° Ω
B. 25 ∠77.9° Ω
C. 6 ∠77.9° Ω
D. 6 ∠12.1° Ω
Answer» D. 6 ∠12.1° Ω
Discussion
18.

Referring to the given circuit, find ZTH if R is 15 kΩ and RL is 38 kΩ.

A. 9.82 ∠-51.3° kΩ
B. 9.2 ∠-38.3° kΩ
C. .38 ∠-51.3° kΩ
D. 80 ∠-38.3° kΩ
Answer» D. 80 ∠-38.3° kΩ
Discussion
19.

Determine VTH when R1 is 180 Ω and XL is 90 Ω.

A. 35∠63.4° V
B. 3.5∠63.4° V
C. 2.2∠0° V
D. 22∠0° V
Answer» C. 2.2∠0° V
Discussion
20.

Referring to the given circuit, find ZTH if VS is 180° V.

A. .82 ∠-51.3° kΩ
B. .38 ∠-51.3° kΩ
C. 80 ∠-38.3° kΩ
D. 9.2 ∠-38.3° kΩ
Answer» C. 80 ∠-38.3° kΩ
Discussion
21.

Referring to the given circuit, what is VTH if VS = 12 ∠0° V?

A. .69 ∠38.7° V
B. .38 ∠38.7° V
C. 2 ∠0° V
D. ∠0° V
Answer» C. 2 ∠0° V
Discussion
22.

For the circuit shown, determine ZTH for the portion of the circuit external to RL.

A. 66.7 ∠-33.7° kΩ
B. 6.67 ∠-333.7° kΩ
C. 14.4 ∠-56.3° kΩ
D. 1.44 ∠-33.7° kΩ
Answer» C. 14.4 ∠-56.3° kΩ
Discussion
23.

Referring to the given circuit, find ZTH for the part of the circuit that is external to RL.

A. 129 ∠21.4° Ω
B. 43.7 ∠68.6° Ω
C. 43.7 ∠21.4° Ω
D. 12.9 ∠68.6° Ω
Answer» C. 43.7 ∠21.4° Ω
Discussion
24.

Referring to the given circuit, determine ZTH as seen by RL.

A. 1444 ∠-48.5° Ω
B. 4176 ∠-73.3° Ω
C. 956 ∠-48.5° Ω
D. 1444 ∠-73.3° Ω
Answer» B. 4176 ∠-73.3° Ω
Discussion
25.

Referring to the given figure, determine ZTH as seen by RL if R1 is changed to 3.3 kΩ.

A. 1488 ∠-70.7° Ω
B. 3859 ∠-31.2° Ω
C. 5180 ∠-50.5° Ω
D. 1828 ∠-50.2° Ω
Answer» E.
Discussion
26.

Determine VTH if R1 is changed to 3.3 kΩ.

A. 0.574 ∠16.7° V
B. 4.63 ∠16.7° V
C. 4.63 ∠39.5° V
D. 0.463 ∠39.5° V
Answer» D. 0.463 ∠39.5° V
Discussion
27.

Referring to the given circuit, what is ZTH if R1 is changed to 220 Ω?

A. 225 ∠12.1° Ω
B. 225 ∠77.9° Ω
C. 46 ∠77.9° Ω
D. 46 ∠12.1° Ω
Answer» D. 46 ∠12.1° Ω
Discussion
28.

Norton's theorem gives

A. An equivalent current source in parallel with an equivalent impedance
B. An equivalent current source in series with an equivalent impedance
C. An equivalent voltage source in parallel with an equivalent impedance
D. An equivalent voltage source in series with an equivalent impedance
Answer» B. An equivalent current source in series with an equivalent impedance
Discussion
29.

Thevenin's theorem provides a method for the reduction of any ac circuit to an equivalent form consisting of an equivalent current source in parallel with an equivalent impedance.

A. True
B. False
Answer» C.
Discussion
30.

Norton's theorem provides a method for the reduction of any ac circuit to an equivalent form consisting of an equivalent voltage source in series with an equivalent impedance.

A. True
B. False
Answer» C.
Discussion
31.

The Norton equivalent current is

A. The current through the load
B. The open-current from the source
C. The short circuit current
D. None of the above
Answer» D. None of the above
Discussion
32.

In order to get maximum power transfer from a capacitive source, the load must

A. Have a capacitive reactance equal to circuit resistance
B. Have an impedance that is the complex conjugate of the source impedance
C. Be as capacitive as it is inductive
D. None of the above
Answer» C. Be as capacitive as it is inductive
Discussion
33.

The superposition theorem is useful for circuit analysis only in ac circuits.

A. True
B. False
Answer» C.
Discussion
34.

Referring to the given circuit, find ZTH if R is 15 kΩ and RL is 38 kΩ.

A. 89.82 ∠-51.3° kΩ
B. 19.2 ∠-38.3° kΩ
C. 9.38 ∠-51.3° kΩ
D. 180 ∠-38.3° kΩ
Answer» D. 180 ∠-38.3° kΩ
Discussion
35.

A Thevenin ac equivalent circuit always consists of an equivalent ac voltage source and an equivalent capacitance.

A. True
B. False
Answer» C.
Discussion
36.

Determine VTH for the circuit external to RL in the given figure.

A. 135 ∠63.4° V
B. 13.5 ∠63.4° V
C. 13.5 ∠0° V
D. 135 ∠0° V
Answer» C. 13.5 ∠0° V
Discussion
37.

In order to get maximum power transfer from a capacitive source, the load must have an impedance that is the complex conjugate of the source impedance.

A. True
B. False
Answer» B. False
Discussion
38.

In an ac circuit, power to the load peaks at the frequency at which the load impedance is the complex conjugate of the output impedance.

A. True
B. False
Answer» B. False
Discussion
39.

Referring to the given circuit, L

A. Must be in parallel with RL
B. Must be placed in parallel with VS
C. Must have a reactance equal to XC
D. Has no effect on the result
Answer» E.
Discussion
40.

The superposition theorem is useful for the analysis of single-source circuits.

A. True
B. False
Answer» C.
Discussion
41.

Like Thevenin's theorem, Norton's theorem provides a method of reducing a more complex circuit to a simpler, more manageable form for analysis.

A. True
B. False
Answer» B. False
Discussion
42.

For the given circuit, find VTH for the circuit external to RL.

A. 4.69 ∠51.3° V
B. 4.69 ∠38.7° V
C. 469 ∠38.7° mV
D. 6 ∠0° V
Answer» C. 469 ∠38.7° mV
Discussion
43.

Determine VTH when R1 is 180 Ω and XL is 90 Ω.

A. 135∠63.4° V
B. 13.5∠63.4° V
C. 12.2∠0° V
D. 122∠0° V
Answer» C. 12.2∠0° V
Discussion
44.

Referring to the given circuit, find ZTH if VS is 180° V.

A. 9.82 ∠-51.3° kΩ
B. 9.38 ∠-51.3° kΩ
C. 180 ∠-38.3° kΩ
D. 19.2 ∠-38.3° kΩ
Answer» C. 180 ∠-38.3° kΩ
Discussion
45.

Referring to the given circuit, what is VTH if VS = 12 ∠0° V?

A. 4.69 ∠38.7° V
B. 9.38 ∠38.7° V
C. 12 ∠0° V
D. 6 ∠0° V
Answer» C. 12 ∠0° V
Discussion
46.

The Thevenin equivalent voltage is

A. equal to the source voltage
B. the same as the load voltage
C. the open circuit voltage
D. none of the above
Answer» D. none of the above
Discussion
47.

An equivalent circuit is one that produces the same voltage and current to a given load as the original circuit that it replaces.

A. 1
B.
Answer» B.
Discussion
48.

Referring to the given circuit, how much power, in watts, is delivered to the speaker at the determined frequency if VS = 4.5 VRMS?

A. 226 mW
B. 2.26 mW
C. 4.24 mW
D. 424 mW
Answer» E.
Discussion
49.

In applying the superposition theorem,

A. the sources are considered one at a time with all others replaced by their internal impedance
B. all sources are considered independently
C. all sources are considered simultaneously
D. the sources are considered one at a time with all others replaced by their internal resistance
Answer» B. all sources are considered independently
Discussion
50.

Referring to the given circuit, what is VTH if VS = 120° V?

A. 4.6938.7° V
B. 9.3838.7° V
C. 120° V
D. 60° V
Answer» C. 120¬∞ V
Discussion