Point +4 on the complex plane is%!

4 units left of the origin on the real axis

4 units above the origin on the j axis

4 units below the origin on the j axis

4 units right of the origin on the real axis

4 units left of the origin on the real axis

The complex number 6 + j6 is equivalent to%!

8.48 ‚Äö√ ‚Ä 90¬¨‚àû

6 ‚Äö√ ‚Ä 45¬¨‚àû

36 ‚Äö√ ‚Ä 45¬¨‚àû

8.48 ‚Äö√ ‚Ä 45¬¨‚àû

8.48 ‚Äö√ ‚Ä 90¬¨‚àû

A capacitor with 150 ≈í¬© of capacitive reactance is across an ac source. The impedance, expressed in polar form, is%!

Z = 150 ‚Äö√ ‚Ä 180¬¨‚àûO

Z = 150 ‚Äö√ ‚Ä 90¬¨‚àûO

Z = 150 ‚Äö√ ‚Ä -90¬¨‚àûO

Z = 150 ‚Äö√ ‚Ä 180¬¨‚àûO

A 47 ≈í¬© resistor and a capacitor with 150 ≈í¬© of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is%!

Z = 47 ≈í¬© + j150 ≈í¬©

Z = 47 ≈í¬© - j150 ≈í¬©

A 2 k≈í¬© resistor is in series with a 0.015 ¬¨¬µF capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle?%!

734 ≈í¬© and ‚Äö√ ‚Ä = -38.9¬¨‚àû

73.4 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû

707 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû

2121 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû

734 ≈í¬© and ‚Äö√ ‚Ä = -38.9¬¨‚àû

In a series RC circuit, when the frequency and the resistance are halved, the impedance%!

Cannot be determined without values

37 + Mcqs in Rc Circuits in Electrical Engineering Page 1 McqOptions

1.	In a lag network, the output voltage lags the input voltage in phase.~!
A.	True
B.	False
Answer» B. False

Discussion

2.	In a parallel RC circuit, there is 100 mA through the resistive branch and 100 mA through the capacitive branch. The total rms current is~!
A.	200 mA
B.	100 mA
C.	282 mA
D.	141 mA
Answer» E.

Discussion

3.	For a certain load, the true power is 150 W and the reactive power is 125 VAR. The apparent power is%!
A.	19.52 W
B.	195.2 W
C.	275 W
D.	25 W
Answer» C. 275 W

Discussion

4.	Complex numbers can be added and subtracted but not multiplied or divided.%!
A.	True
B.	False
Answer» C.

Discussion

5.	When the frequency of the voltage applied to a series RC circuit is increased, the phase angle%!
A.	Increases
B.	Decreases
C.	Remains the same
D.	Becomes erratic
Answer» C. Remains the same

Discussion

6.	A 120 ≈í¬© resistor is in parallel with a capacitor with a capacitive reactance of 40 ≈í¬©. Both components are across a 12 V ac source. What is the magnitude of the total impedance?%!
A.	37.9 ≈í¬©
B.	3.7 ≈í¬©
C.	14,400 ≈í¬©
D.	4,800 ≈í¬©
Answer» B. 3.7 ≈í¬©

Discussion

7.	In an RC circuit, the impedance is determined by both the resistance and the capacitive reactance combined.%!
A.	True
B.	False
Answer» B. False

Discussion

8.	An imaginary number is one that exists only in the mind of the mathematician.%!
A.	True
B.	False
Answer» C.

Discussion

9.	The polar form of a complex number consists of a real part and a j part.%!
A.	True
B.	False
Answer» C.

Discussion

10.	The resistor voltage is always out of phase with the current.%!
A.	True
B.	False
Answer» C.

Discussion

11.	Point +4 on the complex plane is%!
A.	4 units above the origin on the j axis
B.	4 units below the origin on the j axis
C.	4 units right of the origin on the real axis
D.	4 units left of the origin on the real axis
Answer» D. 4 units left of the origin on the real axis

Discussion

12.	When the frequency of the source voltage decreases, the impedance of a parallel RC circuit%!
A.	Increases
B.	Decreases
C.	Does not change
D.	Decreases to zero
Answer» B. Decreases

Discussion

13.	A 12 k≈í¬© resistor is in series with a 0.02 ¬¨¬µF capacitor across a 1.2 kHz ac source. If the current is expressed in polar form as I = 0.3 ‚Äö√ ‚Ä 0¬¨‚àû mA, what is the source voltage expressed in polar form?%!
A.	45.6 V
B.	411.3 V
C.	0.411 V
D.	4.11 V
Answer» E.

Discussion

14.	In the complex plane, the number 14 - j5 is located in the%!
A.	First quadrant
B.	Second quadrant
C.	Third quadrant
D.	Fourth quadrant
Answer» E.

Discussion

15.	A complex number represents a phasor quantity.%!
A.	True
B.	False
Answer» B. False

Discussion

16.	Positive numbers can be represented by points to the right of the origin on the horizontal axis of a graph.%!
A.	True
B.	False
Answer» B. False

Discussion

17.	The complex number 6 + j6 is equivalent to%!
A.	6 ‚Äö√ ‚Ä 45¬¨‚àû
B.	36 ‚Äö√ ‚Ä 45¬¨‚àû
C.	8.48 ‚Äö√ ‚Ä 45¬¨‚àû
D.	8.48 ‚Äö√ ‚Ä 90¬¨‚àû
Answer» D. 8.48 ‚Äö√ ‚Ä 90¬¨‚àû

Discussion

18.	A capacitor with 150 ≈í¬© of capacitive reactance is across an ac source. The impedance, expressed in polar form, is%!
A.	Z = 150
B.	Z = 150 ‚Äö√ ‚Ä 90¬¨‚àûO
C.	Z = 150 ‚Äö√ ‚Ä -90¬¨‚àûO
D.	Z = 150 ‚Äö√ ‚Ä 180¬¨‚àûO
Answer» D. Z = 150 ‚Äö√ ‚Ä 180¬¨‚àûO

Discussion

19.	In the complex plane, the number 4 + j3 is located in the%!
A.	First quadrant
B.	Second quadrant
C.	Third quadrant
D.	Fourth quadrant
Answer» B. Second quadrant

Discussion

20.	A 6 kHz sinusoidal voltage is applied to a series RC circuit. The frequency of the voltage across the resistor is%!
A.	0 Hz
B.	12 kHz
C.	6 kHz
D.	18 kHz
Answer» D. 18 kHz

Discussion

21.	What is the value of the hypotenuse of a right triangle whose sides are 12 and 18?%!
A.	4.24
B.	3.46
C.	2.16
D.	21.63
Answer» E.

Discussion

22.	Apparent power is expressed in watts.%!
A.	True
B.	False
Answer» C.

Discussion

23.	The circuit phase angle is the angle between the total current and the applied (source) voltage.%!
A.	True
B.	False
Answer» B. False

Discussion

24.	A 47 ≈í¬© resistor and a capacitor with a capacitive reactance of 120 ≈í¬© are in series across an ac source. What is the circuit impedance, Z?%!
A.	129 ≈í¬©
B.	12.9 ≈í¬©
C.	167 ≈í¬©
D.	73 ≈í¬©
Answer» B. 12.9 ≈í¬©

Discussion

25.	A 470 ≈í¬© resistor and a 0.2 ¬¨¬µF capacitor are in parallel across a 2.5 kHz ac source. The admittance, Y, in rectangular form, is%!
A.	212 ≈í¬©
B.	2.12 mS + j3.14 mS
C.	3.14 mS + j2.12 mS
D.	318.3 ≈í¬©
Answer» C. 3.14 mS + j2.12 mS

Discussion

26.	A filter passes all frequencies.%!
A.	True
B.	False
Answer» C.

Discussion

27.	A positive angle of 30¬¨‚àû is equivalent to a negative angle of%!
A.	-30¬¨‚àû
B.	-330¬¨‚àû
C.	-60¬¨‚àû
D.	-180¬¨‚àû
Answer» C. -60¬¨‚àû

Discussion

28.	When the frequency of the voltage applied to a series RC circuit is decreased, the impedance%!
A.	Increases
B.	Decreases
C.	Remains the same
D.	Doubles
Answer» B. Decreases

Discussion

29.	A 47 ≈í¬© resistor and a capacitor with 150 ≈í¬© of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is%!
A.	Z = 47 ≈í¬© + j150 ≈í¬©
B.	Z = 47 ≈í¬© - j150 ≈í¬©
C.	Z = 197 ≈í¬©
D.	Z = 103 ≈í¬©
Answer» C. Z = 197 ≈í¬©

Discussion

30.	The impedance of a series RC circuit varies directly with frequency.%!
A.	True
B.	False
Answer» C.

Discussion

31.	The power factor (PF) indicates how much of the apparent power is true power.%!
A.	True
B.	False
Answer» B. False

Discussion

32.	What is the angular difference between +j4 and -j4?%!
A.	30¬¨‚àû
B.	90¬¨‚àû
C.	180¬¨‚àû
D.	270¬¨‚àû
Answer» D. 270¬¨‚àû

Discussion

33.	A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 k≈í¬©. Current flow in the circuit is%!
A.	9.2 mA
B.	92 mA
C.	4.6 mA
D.	460 mA
Answer» D. 460 mA

Discussion

34.	A 2 k≈í¬© resistor is in series with a 0.015 ¬¨¬µF capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle?%!
A.	73.4 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû
B.	707 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû
C.	2121 ≈í¬© and ‚Äö√ ‚Ä = -19.5¬¨‚àû
D.	734 ≈í¬© and ‚Äö√ ‚Ä = -38.9¬¨‚àû
Answer» D. 734 ≈í¬© and ‚Äö√ ‚Ä = -38.9¬¨‚àû

Discussion

35.	An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45¬¨‚àû, the following condition must exist:%!
A.	R = XC
B.	R > XC
C.	R < XC
D.	R = 5XC
Answer» D. R = 5XC

Discussion

36.	In a series RC circuit, when the frequency and the resistance are halved, the impedance%!
A.	Doubles
B.	Is halved
C.	Is reduced to one-fourth
D.	Cannot be determined without values
Answer» E.

Discussion

37.	In a series RC circuit, 12 V(rms) is measured across the resistor and 15 V(rms) is measured across the capacitor. The rms source voltage is%!
A.	3 V
B.	27 V
C.	19.2 V
D.	1.9 V
Answer» D. 1.9 V

Discussion

Explore topic-wise MCQs in Electrical Engineering.

In a lag network, the output voltage lags the input voltage in phase.~!

In a parallel RC circuit, there is 100 mA through the resistive branch and 100 mA through the capacitive branch. The total rms current is~!

For a certain load, the true power is 150 W and the reactive power is 125 VAR. The apparent power is%!

Complex numbers can be added and subtracted but not multiplied or divided.%!

When the frequency of the voltage applied to a series RC circuit is increased, the phase angle%!

A 120 ≈í¬© resistor is in parallel with a capacitor with a capacitive reactance of 40 ≈í¬©. Both components are across a 12 V ac source. What is the magnitude of the total impedance?%!

In an RC circuit, the impedance is determined by both the resistance and the capacitive reactance combined.%!

An imaginary number is one that exists only in the mind of the mathematician.%!

The polar form of a complex number consists of a real part and a j part.%!

The resistor voltage is always out of phase with the current.%!

Point +4 on the complex plane is%!

When the frequency of the source voltage decreases, the impedance of a parallel RC circuit%!

A 12 k≈í¬© resistor is in series with a 0.02 ¬¨¬µF capacitor across a 1.2 kHz ac source. If the current is expressed in polar form as I = 0.3 ‚Äö√ ‚Ä 0¬¨‚àû mA, what is the source voltage expressed in polar form?%!

In the complex plane, the number 14 - j5 is located in the%!

A complex number represents a phasor quantity.%!

Positive numbers can be represented by points to the right of the origin on the horizontal axis of a graph.%!

The complex number 6 + j6 is equivalent to%!

A capacitor with 150 ≈í¬© of capacitive reactance is across an ac source. The impedance, expressed in polar form, is%!

In the complex plane, the number 4 + j3 is located in the%!

A 6 kHz sinusoidal voltage is applied to a series RC circuit. The frequency of the voltage across the resistor is%!

What is the value of the hypotenuse of a right triangle whose sides are 12 and 18?%!

Apparent power is expressed in watts.%!

The circuit phase angle is the angle between the total current and the applied (source) voltage.%!

A 47 ≈í¬© resistor and a capacitor with a capacitive reactance of 120 ≈í¬© are in series across an ac source. What is the circuit impedance, Z?%!

A 470 ≈í¬© resistor and a 0.2 ¬¨¬µF capacitor are in parallel across a 2.5 kHz ac source. The admittance, Y, in rectangular form, is%!

A filter passes all frequencies.%!

A positive angle of 30¬¨‚àû is equivalent to a negative angle of%!

When the frequency of the voltage applied to a series RC circuit is decreased, the impedance%!

A 47 ≈í¬© resistor and a capacitor with 150 ≈í¬© of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is%!

The impedance of a series RC circuit varies directly with frequency.%!

The power factor (PF) indicates how much of the apparent power is true power.%!

What is the angular difference between +j4 and -j4?%!

A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 k≈í¬©. Current flow in the circuit is%!

A 2 k≈í¬© resistor is in series with a 0.015 ¬¨¬µF capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle?%!

An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45¬¨‚àû, the following condition must exist:%!

In a series RC circuit, when the frequency and the resistance are halved, the impedance%!

In a series RC circuit, 12 V(rms) is measured across the resistor and 15 V(rms) is measured across the capacitor. The rms source voltage is%!