553 + Mcqs in Electrical Engineering McqOptions

1.	The reactive voltages, VL and VC, cancel at resonance.
A.	True
B.	False
Answer» B. False

Discussion

2.	The quality factor (Q) is the ratio of true power to apparent power.
A.	True
B.	False
Answer» C.

Discussion

3.	A simple three-phase generator consists of three conductive loops separated by 120 .
A.	True
B.	False
Answer» B. False

Discussion

4.	Polyphase is characterized by two or more sinusoidal voltages, each having a different phase angle.
A.	True
B.	False
Answer» B. False

Discussion

5.	In a -connected generator, there is a 120 difference between each line current and the nearest phase current.
A.	True
B.	False
Answer» C.

Discussion

6.	Power is measured in a three-phase load by using an ammeter.
A.	True
B.	False
Answer» C.

Discussion

7.	Free electrons make current possible.
A.	True
B.	False
Answer» B. False

Discussion

8.	If 750 A is flowing through 11 k of resistance, what is the voltage drop across the resistor?
A.	8.25 V
B.	82.5 V
C.	14.6 V
D.	146 V
Answer» B. 82.5 V

Discussion

9.	At the end of a 14 day period, your utility bill shows that you have used 18 kWh. What is your average daily power?
A.	1.286 kWh
B.	12.85 kWh
C.	535 kWh
D.	252 kWh
Answer» B. 12.85 kWh

Discussion

10.	A half-watt is equal to how many milliwatts?
A.	5,000 mW
B.	5 mW
C.	500 mW
D.	50 mW
Answer» D. 50 mW

Discussion

11.	Series aiding is a term sometimes used to describe voltage sources of the same polarity in series.
A.	True
B.	False
Answer» B. False

Discussion

12.	Faraday's law states that relative motion between a magnetic field and a coil induces a voltage across the coil.
A.	True
B.	False
Answer» B. False

Discussion

13.	Inductance is indirectly proportional to the square of the number of turns, the permeability, and the cross-sectional area of the core.
A.	True
B.	False
Answer» C.

Discussion

14.	A filter passes all frequencies.
A.	True
B.	False
Answer» C.

Discussion

15.	To tune a parallel resonant circuit to a higher frequency, the capacitance should be
A.	increased
B.	decreased
C.	left alone
D.	replaced with inductance
Answer» C. left alone

Discussion

16.	A series resonant circuit is commonly called a tank circuit.
A.	True
B.	False
Answer» C.

Discussion

17.	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

18.	If there are a total of 120 mA into a parallel circuit consisting of three branches, and two of the branch currents are 40 mA and 10 mA, the third branch current is
A.	50 mA
B.	70 mA
C.	120 mA
D.	40 mA
Answer» C. 120 mA

Discussion

19.	In a parallel circuit, the branch with the lowest resistance has the most current.
A.	True
B.	False
Answer» B. False

Discussion

20.	The superposition theorem is useful for the analysis of single-source circuits.
A.	True
B.	False
Answer» C.

Discussion

21.	What is the current through R2?
A.	3.19 A
B.	319 mA
C.	1.73 A
D.	173 mA
Answer» E.

Discussion

22.	Find branch current IR2.
A.	5.4 mA
B.	5.4 mA
C.	113.0 mA
D.	119.6 mA
Answer» D. 119.6 mA

Discussion

23.	Third-order determinants are evaluated by the expansion method or by the cofactor method.
A.	True
B.	False
Answer» B. False

Discussion

24.	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

25.	In an RL integrating circuit, the output voltage is taken across the inductor.
A.	True
B.	False
Answer» C.

Discussion

26.	A certain appliance uses 350 W. If it is allowed to run continuously for 24 days, how many kilowatt-hours of energy does it consume?
A.	20.16 kWh
B.	201.6 kWh
C.	2.01 kWh
D.	8.4 kWh
Answer» C. 2.01 kWh

Discussion

27.	The following resistors (one each) are connected in a series circuit: 470 , 680 , 1 k, and 1.2 k. The voltage source is 20 V. Current through the 680 resistor is approximately
A.	60 mA
B.	30 mA
C.	6 mA
D.	300 mA
Answer» D. 300 mA

Discussion

28.	A balanced load is one in which all the impedances are equal.
A.	True
B.	False
Answer» B. False

Discussion

29.	The quantity 43 10-3 is the same as
A.	0.043
B.	0.430
C.	430
D.	43,000
Answer» B. 0.430

Discussion

30.	The sum of all the voltage drops around a single closed loop in a circuit is zero.
A.	True
B.	False
Answer» B. False

Discussion

31.	A phasor represents
A.	the magnitude and a quantity direction
B.	the width of a quantity
C.	the phase angle
D.	the magnitude of a quantity
Answer» B. the width of a quantity

Discussion

32.	When the frequency is decreased, the impedance of a parallel RL circuit
A.	increases
B.	decreases
C.	remains constant
D.	is not a factor
Answer» C. remains constant

Discussion

33.	Referring to Problem 23, the reactive power is
A.	10 mVAR
B.	100 mVAR
C.	6.76 mVAR
D.	148 mVAR
Answer» C. 6.76 mVAR

Discussion

34.	When the frequency of the voltage applied to a series RL circuit is decreased, the impedance
A.	decreases
B.	increases
C.	does not change
D.	cannot be determined without values
Answer» B. increases

Discussion

35.	In a parallel RL circuit, there are 3 A rms in the resistive branch and 3 A rms in the inductive branch. The total rms current is
A.	6 A
B.	424 mA
C.	4.24 A
D.	42.4 A
Answer» D. 42.4 A

Discussion

36.	When the resistor voltage in a series RL circuit becomes less than the inductor voltage, the phase angle
A.	increases
B.	decreases
C.	is not affected
D.	cannot be determined
Answer» B. decreases

Discussion

37.	In an RC low-pass filter, the output voltage is taken across the resistor and the output lags the input voltage.
A.	True
B.	False
Answer» C.

Discussion

38.	In an RL low-pass filter, the output voltage is taken across the inductor and the output lags the input.
A.	True
B.	False
Answer» C.

Discussion

39.	A band-pass filter rejects all frequencies within a band between a lower and an upper critical frequency and passes all others.
A.	True
B.	False
Answer» C.

Discussion

40.	A band-stop filter passes frequencies between its lower and upper critical frequencies and rejects all others.
A.	True
B.	False
Answer» C.

Discussion

41.	The output voltage is 63.3% of its maximum at the critical frequencies.
A.	True
B.	False
Answer» C.

Discussion

42.	Total current in an RL circuit always lags the source voltage.
A.	True
B.	False
Answer» B. False

Discussion

43.	At a certain frequency, the output voltage of a filter is 6 V and the input is 12 V. The voltage ratio in decibels is
A.	6.02 dB
B.	6.02 dB
C.	12.04 dB
D.	12.04 dB
Answer» C. 12.04 dB

Discussion

44.	The resistor voltage in an RL circuit is always out of phase with the current.
A.	True
B.	False
Answer» C.

Discussion

45.	A filter passes certain frequencies and rejects others.
A.	True
B.	False
Answer» B. False

Discussion

46.	An RC high-pass filter consists of a 0.2 F capacitor and a 220 resistor. The output is taken across the resistor. The circuit's critical frequency is
A.	723 Hz
B.	7,234 Hz
C.	362 Hz
D.	3,617 Hz
Answer» E.

Discussion

47.	In a certain low-pass filter, fc = 3.5 kHz. Its passband is
A.	0 Hz to 3.5 kHz
B.	0 Hz
C.	3.5 kHz
D.	7 kHz
Answer» B. 0 Hz

Discussion

48.	The bandwidth of a resonant filter is determined by the quality factor (Q) of the circuit and the resonant frequency.
A.	True
B.	False
Answer» B. False

Discussion

49.	The phase angle ( ) of a series RL circuit varies directly with frequency.
A.	True
B.	False
Answer» B. False

Discussion

50.	In an RL circuit, the impedance is determined by both the resistance and the inductive reactance combined.
A.	True
B.	False
Answer» B. False

Discussion

Explore topic-wise MCQs in Testing Subject.

The reactive voltages, VL and VC, cancel at resonance.

The quality factor (Q) is the ratio of true power to apparent power.

A simple three-phase generator consists of three conductive loops separated by 120 .

Polyphase is characterized by two or more sinusoidal voltages, each having a different phase angle.

In a -connected generator, there is a 120 difference between each line current and the nearest phase current.

Power is measured in a three-phase load by using an ammeter.

Free electrons make current possible.

If 750 A is flowing through 11 k of resistance, what is the voltage drop across the resistor?

At the end of a 14 day period, your utility bill shows that you have used 18 kWh. What is your average daily power?

A half-watt is equal to how many milliwatts?

Series aiding is a term sometimes used to describe voltage sources of the same polarity in series.

Faraday's law states that relative motion between a magnetic field and a coil induces a voltage across the coil.

Inductance is indirectly proportional to the square of the number of turns, the permeability, and the cross-sectional area of the core.

A filter passes all frequencies.

To tune a parallel resonant circuit to a higher frequency, the capacitance should be

A series resonant circuit is commonly called a tank circuit.

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.

If there are a total of 120 mA into a parallel circuit consisting of three branches, and two of the branch currents are 40 mA and 10 mA, the third branch current is

In a parallel circuit, the branch with the lowest resistance has the most current.

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

What is the current through R2?

Find branch current IR2.

Third-order determinants are evaluated by the expansion method or by the cofactor method.

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

In an RL integrating circuit, the output voltage is taken across the inductor.

A certain appliance uses 350 W. If it is allowed to run continuously for 24 days, how many kilowatt-hours of energy does it consume?

The following resistors (one each) are connected in a series circuit: 470 , 680 , 1 k, and 1.2 k. The voltage source is 20 V. Current through the 680 resistor is approximately

A balanced load is one in which all the impedances are equal.

The quantity 43 10-3 is the same as

The sum of all the voltage drops around a single closed loop in a circuit is zero.

A phasor represents

When the frequency is decreased, the impedance of a parallel RL circuit

Referring to Problem 23, the reactive power is

When the frequency of the voltage applied to a series RL circuit is decreased, the impedance

In a parallel RL circuit, there are 3 A rms in the resistive branch and 3 A rms in the inductive branch. The total rms current is

When the resistor voltage in a series RL circuit becomes less than the inductor voltage, the phase angle

In an RC low-pass filter, the output voltage is taken across the resistor and the output lags the input voltage.

In an RL low-pass filter, the output voltage is taken across the inductor and the output lags the input.

A band-pass filter rejects all frequencies within a band between a lower and an upper critical frequency and passes all others.

A band-stop filter passes frequencies between its lower and upper critical frequencies and rejects all others.

The output voltage is 63.3% of its maximum at the critical frequencies.

Total current in an RL circuit always lags the source voltage.

At a certain frequency, the output voltage of a filter is 6 V and the input is 12 V. The voltage ratio in decibels is

The resistor voltage in an RL circuit is always out of phase with the current.

A filter passes certain frequencies and rejects others.

An RC high-pass filter consists of a 0.2 F capacitor and a 220 resistor. The output is taken across the resistor. The circuit's critical frequency is

In a certain low-pass filter, fc = 3.5 kHz. Its passband is

The bandwidth of a resonant filter is determined by the quality factor (Q) of the circuit and the resonant frequency.

The phase angle ( ) of a series RL circuit varies directly with frequency.

In an RL circuit, the impedance is determined by both the resistance and the inductive reactance combined.