29 + Mcqs in Rlc Circuits And Resonance Page 1 McqOptions

1.	A 6.8 k≈í¬© resistor, a 7 mH coil, and a 0.02 ¬¨¬µF capacitor are in parallel across a 17 kHz ac source. The coil's internal resistance, RW, is 30 ≈í¬©. The equivalent parallel resistance, Rp(eq), is%!
A.	1,878 ≈í¬©
B.	18,780 ≈í¬©
C.	18,750 ≈í¬©
D.	626 ≈í¬©
Answer» C. 18,750 ≈í¬©

Discussion

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

Discussion

3.	At series resonance, the inductive reactance and capacitive reactance are never equal.%!
A.	True
B.	False
Answer» C.

Discussion

4.	A certain series resonant circuit has a bandwidth of 2 kHz. If the existing coil is replaced with one having a higher value of Q, the bandwidth will%!
A.	Increase
B.	Remain the same
C.	Decrease
D.	Be less selective
Answer» D. Be less selective

Discussion

5.	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

6.	A 10 ≈í¬© resistor, a 90 mH coil, and a 0.015 ¬¨¬µF capacitor are in series across an ac source. The impedance magnitude at 1,200 Hz below fr is%!
A.	1,616 ≈í¬©
B.	161 ≈í¬©
C.	3,387 ≈í¬©
D.	1,771 ≈í¬©
Answer» B. 161 ≈í¬©

Discussion

7.	A lower Q produces a narrower bandwidth.%!
A.	True
B.	False
Answer» C.

Discussion

8.	In a series RLC circuit, the larger reactance determines the net reactance of the circuit.%!
A.	True
B.	False
Answer» B. False

Discussion

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

Discussion

10.	If the value of C in a series RLC circuit is decreased, the resonant frequency increases%!
A.	True
B.	False
Answer» B. False

Discussion

11.	In a parallel RLC circuit, the smaller reactance determines the net reactance of the circuit.%!
A.	True
B.	False
Answer» B. False

Discussion

12.	In a series RLC circuit, the current is minimum at resonance.%!
A.	True
B.	False
Answer» C.

Discussion

13.	Resonance is a condition in a series RLC circuit in which the capacitive and inductive reactances are equal in magnitude.%!
A.	True
B.	False
Answer» B. False

Discussion

14.	The impedance at the resonant frequency of a series RLC circuit with L = 20 mH, C = 0.02 ¬¨¬µF, and RW = 90 ≈í¬© is%!
A.	0 ≈í¬©
B.	90 ≈í¬©
C.	20 ≈í¬©
D.	40 ≈í¬©
Answer» C. 20 ≈í¬©

Discussion

15.	A 15 ≈í¬© resistor, a 220 ¬¨¬µH coil, and a 60 pF capacitor are in series across an ac source. What is the bandwidth of the circuit?%!
A.	138 MHz
B.	10,866 Hz
C.	1,907 Hz
D.	138 kHz
Answer» C. 1,907 Hz

Discussion

16.	A resonant circuit has a lower critical frequency of 7 kHz and an upper critical frequency of 13 kHz. The bandwidth of the circuit is%!
A.	7 kHz
B.	13 kHz
C.	20 kHz
D.	4 kHz
Answer» E.

Discussion

17.	XL and XC have opposing effects in an RLC circuit.%!
A.	True
B.	False
Answer» B. False

Discussion

18.	A 24 ≈í¬© resistor, an inductor with a reactance of 120 ≈í¬©, and a capacitor with a reactance of 120 ≈í¬© are in series across a 60 V source. The circuit is at resonance. The voltage across the inductor is%!
A.	60 V
B.	660 V
C.	30 V
D.	300 V
Answer» E.

Discussion

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

Discussion

20.	A 90 ≈í¬© resistor, a coil with 30 ≈í¬© of reactance, and a capacitor with 50 ≈í¬© of reactance are in series across a 12 V ac source. The current through the resistor is%!
A.	9 mA
B.	90 mA
C.	13 mA
D.	130 mA
Answer» E.

Discussion

21.	/_In a certain series resonant circuit, VC = 125 V, VL = 125 V, and VR = 40 V. The value of the source voltage is?
A.	125 V
B.	250 V
C.	290 V
D.	40 V
Answer» E.

Discussion

22.	/_If the value of C in a series RLC circuit is decreased, the resonant frequency?
A.	Is not affected
B.	Increases
C.	Is reduced to zero
D.	Decreases
Answer» C. Is reduced to zero

Discussion

23.	_ A resistor of 3 k≈í¬©, a 0.05 ¬¨¬µF capacitor, and a 120 mH coil are in series across a 5 kHz, 20 V ac source. What is the impedance, expressed in polar form?$?
A.	636 ≈í¬©
B.	3,769 ≈í¬©
C.	433 ≈í¬©
D.	4,337 ≈í¬©
Answer» E.

Discussion

24.	_ If the resistance in parallel with a parallel resonant circuit is reduced, the bandwidth$?
A.	Disappears
B.	Becomes sharper
C.	Increases
D.	Decreases
Answer» E.

Discussion

25.	A 12 ≈í¬© resistor, a 40 ¬¨¬µF capacitor, and an 8 mH coil are in series across an ac source. The resonant frequency is$?
A.	28.1 Hz
B.	281 Hz
C.	2,810 Hz
D.	10 kHz
Answer» C. 2,810 Hz

Discussion

26.	A 200 ≈í¬© resistor, a coil with 30 ≈í¬© of reactance, and a capacitor of unknown reactance are in series across an ac source. The circuit is at resonance. Circuit impedance is$?
A.	230 ≈í¬©
B.	170 ≈í¬©
C.	200 ≈í¬©
D.	Cannot be determined
Answer» D. Cannot be determined

Discussion

27.	A 9 mH coil is in parallel with a 0.015 ¬¨¬µF capacitor across an 18 kHz ac source. The coil's internal resistance RW, is 60 ≈í¬©. The circuit impedance is$
A.	17,340 ≈í¬©
B.	1,734 ≈í¬©
C.	290 ≈í¬©
D.	1,018 ≈í¬©
Answer» B. 1,734 ≈í¬©

Discussion

28.	A certain series RLC circuit with a 200 Hz, 15 V ac source has the following values: R = 12 ≈í¬©, C = 80 ¬¨¬µF, and L = 10 mH. The total impedance, expressed in polar form, is#
A.	12.28 ‚Äö√ ‚Ä 12.34¬¨‚àû ≈í¬©
B.	12.57 ‚Äö√ ‚Ä 12.34¬¨‚àû ≈í¬©
C.	9.95 ‚Äö√ ‚Ä 12.34¬¨‚àû ≈í¬©
D.	12.62 ‚Äö√ ‚Ä 12.34¬¨‚àû ≈í¬©
Answer» B. 12.57 ‚Äö√ ‚Ä 12.34¬¨‚àû ≈í¬©

Discussion

29.	A 15 ≈í¬© resistor, an inductor with 8 ≈í¬© inductive reactance, and a capacitor with 12 ≈í¬© capacitive reactance are in parallel across an ac voltage source. The circuit impedance is#
A.	12.7 ≈í¬©
B.	127 ≈í¬©
C.	4,436 ≈í¬©
D.	6,174 ≈í¬©
Answer» B. 127 ≈í¬©

Discussion

Explore topic-wise MCQs in Electrical Engineering.

A 6.8 k≈í¬© resistor, a 7 mH coil, and a 0.02 ¬¨¬µF capacitor are in parallel across a 17 kHz ac source. The coil's internal resistance, RW, is 30 ≈í¬©. The equivalent parallel resistance, Rp(eq), is%!

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

At series resonance, the inductive reactance and capacitive reactance are never equal.%!

A certain series resonant circuit has a bandwidth of 2 kHz. If the existing coil is replaced with one having a higher value of Q, the bandwidth will%!

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

A 10 ≈í¬© resistor, a 90 mH coil, and a 0.015 ¬¨¬µF capacitor are in series across an ac source. The impedance magnitude at 1,200 Hz below fr is%!

A lower Q produces a narrower bandwidth.%!

In a series RLC circuit, the larger reactance determines the net reactance of the circuit.%!

A series resonant circuit is commonly called a tank circuit.%!

If the value of C in a series RLC circuit is decreased, the resonant frequency increases%!

In a parallel RLC circuit, the smaller reactance determines the net reactance of the circuit.%!

In a series RLC circuit, the current is minimum at resonance.%!

Resonance is a condition in a series RLC circuit in which the capacitive and inductive reactances are equal in magnitude.%!

The impedance at the resonant frequency of a series RLC circuit with L = 20 mH, C = 0.02 ¬¨¬µF, and RW = 90 ≈í¬© is%!

A 15 ≈í¬© resistor, a 220 ¬¨¬µH coil, and a 60 pF capacitor are in series across an ac source. What is the bandwidth of the circuit?%!

A resonant circuit has a lower critical frequency of 7 kHz and an upper critical frequency of 13 kHz. The bandwidth of the circuit is%!

XL and XC have opposing effects in an RLC circuit.%!

A 24 ≈í¬© resistor, an inductor with a reactance of 120 ≈í¬©, and a capacitor with a reactance of 120 ≈í¬© are in series across a 60 V source. The circuit is at resonance. The voltage across the inductor is%!

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

A 90 ≈í¬© resistor, a coil with 30 ≈í¬© of reactance, and a capacitor with 50 ≈í¬© of reactance are in series across a 12 V ac source. The current through the resistor is%!

*/*_In a certain series resonant circuit, VC = 125 V, VL = 125 V, and VR = 40 V. The value of the source voltage is?

*/*_If the value of C in a series RLC circuit is decreased, the resonant frequency?

_ A resistor of 3 k≈í¬©, a 0.05 ¬¨¬µF capacitor, and a 120 mH coil are in series across a 5 kHz, 20 V ac source. What is the impedance, expressed in polar form?$?

_ If the resistance in parallel with a parallel resonant circuit is reduced, the bandwidth$?

A 12 ≈í¬© resistor, a 40 ¬¨¬µF capacitor, and an 8 mH coil are in series across an ac source. The resonant frequency is$?

A 200 ≈í¬© resistor, a coil with 30 ≈í¬© of reactance, and a capacitor of unknown reactance are in series across an ac source. The circuit is at resonance. Circuit impedance is$?

A 9 mH coil is in parallel with a 0.015 ¬¨¬µF capacitor across an 18 kHz ac source. The coil's internal resistance RW, is 60 ≈í¬©. The circuit impedance is$

A certain series RLC circuit with a 200 Hz, 15 V ac source has the following values: R = 12 ≈í¬©, C = 80 ¬¨¬µF, and L = 10 mH. The total impedance, expressed in polar form, is#

A 15 ≈í¬© resistor, an inductor with 8 ≈í¬© inductive reactance, and a capacitor with 12 ≈í¬© capacitive reactance are in parallel across an ac voltage source. The circuit impedance is#

/_In a certain series resonant circuit, VC = 125 V, VL = 125 V, and VR = 40 V. The value of the source voltage is?

/_If the value of C in a series RLC circuit is decreased, the resonant frequency?