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

cannot be determined without values

If the frequency is halved and the resistance is doubled, the impedance of a series circuit

cannot be determined without values

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

cannot be determined without values

To increase the current in a series circuit, the frequency

cannot be determined without values

If the frequency is halved and the resistance is doubled, the impedance of a series RL circuit

cannot be determined without values

To increase the current in a series RL circuit, the frequency

cannot be determined without values

43 + Mcqs in Rl Circuits in Electrical Engineering Page 1 McqOptions

1.	Referring to Problem 23, the true power is
A.	68.6 mW
B.	686 mW
C.	564 mW
D.	121.8 mW
Answer» B. 686 mW

Discussion

2.	A 470 resistor and a coil with 125 inductive reactance are in parallel. Both components are across a 15 V ac voltage source. Current through the inductor is
A.	152 mA
B.	32 mA
C.	12 mA
D.	120 mA
Answer» E.

Discussion

3.	The impedance of an circuit varies inversely with frequency.
A.	True
B.	False
Answer» C.

Discussion

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

Discussion

5.	In an circuit, part of the power is resistive and part is reactive.
A.	True
B.	False
Answer» B. False

Discussion

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

Discussion

7.	Which of the following power factors results in less energy loss in an circuit?
A.	1
B.	0.8
C.	0.4
D.	0.2
Answer» E.

Discussion

8.	A 140 resistor is in parallel with an inductor having 60 inductive reactance. Both components are across a 12 V ac source. The magnitude of the total impedance is
A.	5.51
B.	55.15
C.	90
D.	200
Answer» C. 90

Discussion

9.	A 1.5 k resistor and a coil with a 2.2 k inductive reactance are in series across an 18 V ac source. The power factor is
A.	564
B.	0.564
C.	6.76
D.	55.7
Answer» C. 6.76

Discussion

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

Discussion

11.	When the frequency of the voltage applied to a series circuit is increased, the phase angle
A.	decreases
B.	increases
C.	does not change
D.	cannot be determined without values
Answer» C. does not change

Discussion

12.	If the frequency is halved and the resistance is doubled, the impedance of a series circuit
A.	doubles
B.	halves
C.	remains constant
D.	cannot be determined without values
Answer» E.

Discussion

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

Discussion

14.	In a parallel 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

15.	When the resistor voltage in a series 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

16.	In a series circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage is
A.	18.4 V
B.	26.0 V
C.	2 V
D.	20 V
Answer» C. 2 V

Discussion

17.	To increase the current in a series circuit, the frequency
A.	should be increased
B.	should be decreased
C.	should be constant
D.	cannot be determined without values
Answer» C. should be constant

Discussion

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

Discussion

19.	A 1.2 k resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is
A.	152.6
B.	1,526
C.	1,200
D.	942
Answer» C. 1,200

Discussion

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

Discussion

21.	The impedance of an RL circuit varies inversely with frequency.
A.	rue
B.	alse
Answer» C.

Discussion

22.	In an RL circuit, part of the power is resistive and part is reactive.
A.	rue
B.	alse
Answer» B. alse

Discussion

23.	The phase angle (?) of a series RL circuit varies directly with frequency.
A.	rue
B.	alse
Answer» B. alse

Discussion

24.	When the frequency of the voltage applied to a series RL circuit is decreased, the impedance decreases
A.	rue
B.	alse
Answer» B. alse

Discussion

25.	A power factor of 1 indicates a purely reactive circuit, and a power factor of 0 indicates a purely resistive circuit.
A.	1
B.
Answer» C.

Discussion

26.	If a load is purely inductive and the reactive power is 12 VAR, the apparent power is
A.	0 VA
B.	12 VA
C.	6 VA
D.	24 VA
Answer» C. 6 VA

Discussion

27.	A filter passes certain frequencies and rejects others.
A.	1
B.
Answer» B.

Discussion

28.	The power factor indicates how much of the apparent power is reactive power.
A.	1
B.
Answer» C.

Discussion

29.	In an RL circuit, the impedance is determined by both the resistance and the inductive reactance combined.
A.	1
B.
C.	1
D.
Answer» B.

Discussion

30.	Which of the following power factors results in less energy loss in an RL circuit?
A.	1
B.	0.8
C.	0.4
D.	0.2
Answer» E.

Discussion

31.	A 1.2 k resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is
A.	152.6
B.	1526
C.	1200
D.	942
Answer» C. 1200

Discussion

32.	The resistor voltage in an RL circuit is always out of phase with the current.
A.	1
B.
Answer» C.

Discussion

33.	A 140 resistor is in parallel with an inductor having 60 inductive reactance. Both components are across a 12 V ac source. The magnitude of the total impedance is
A.	5.51
B.	55.15
C.	90
D.	200
Answer» C. 90

Discussion

34.	Total current in an RL circuit always lags the source voltage.
A.	1
B.
C.	1
D.
Answer» B.

Discussion

35.	A 470 resistor and a coil with 125 inductive reactance are in parallel. Both components are across a 15 V ac voltage source. Current through the inductor is
A.	152 mA
B.	32 mA
C.	12 mA
D.	120 mA
Answer» E.

Discussion

36.	Referring to Problem 18, the circuit impedance is
A.	458 ‚Äì76¬∞
B.	4.58 ‚Äì76¬∞
C.	45876¬∞
D.	4.5876¬∞
Answer» D. 4.5876¬∞

Discussion

37.	If the frequency is halved and the resistance is doubled, the impedance of a series RL circuit
A.	doubles
B.	halves
C.	remains constant
D.	cannot be determined without values
Answer» E.

Discussion

38.	To increase the current in a series RL circuit, the frequency
A.	should be increased
B.	should be decreased
C.	should be constant
D.	cannot be determined without values
Answer» C. should be constant

Discussion

39.	The voltages in Problem 5 are measured at a certain frequency. To make the resistor voltage less than the inductor voltage, the frequency is
A.	increased
B.	decreased
C.	doubled
D.	not a factor
Answer» B. decreased

Discussion

40.	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

41.	In a series RL circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage is
A.	18.4 V
B.	26.0 V
C.	2 V
D.	20 V
Answer» C. 2 V

Discussion

42.	A 12 k resistor is in series with a 90 mH coil across an 8 kHz ac source. Current flow in the circuit, expressed in polar form, is I = 0.30¬∞ mA. The source voltage, expressed in polar form, is
A.	3.8420.6¬∞ V
B.	12.820.6¬∞ V
C.	0.320.6¬∞ V
D.	13.8469.4¬∞ V
Answer» B. 12.820.6¬∞ V

Discussion

43.	A 1.5 k resistor and a coil with a 2.2 k inductive reactance are in series across an 18 V ac source. The power factor is
A.	564
B.	0.564
C.	6.76
D.	55.7
Answer» C. 6.76

Discussion

Explore topic-wise MCQs in Electrical Engineering.

Referring to Problem 23, the true power is

A 470 resistor and a coil with 125 inductive reactance are in parallel. Both components are across a 15 V ac voltage source. Current through the inductor is

The impedance of an circuit varies inversely with frequency.

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

In an circuit, part of the power is resistive and part is reactive.

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

Which of the following power factors results in less energy loss in an circuit?

A 140 resistor is in parallel with an inductor having 60 inductive reactance. Both components are across a 12 V ac source. The magnitude of the total impedance is

A 1.5 k resistor and a coil with a 2.2 k inductive reactance are in series across an 18 V ac source. The power factor is

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

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

If the frequency is halved and the resistance is doubled, the impedance of a series circuit

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

In a parallel 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 circuit becomes less than the inductor voltage, the phase angle

In a series circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage is

To increase the current in a series circuit, the frequency

Total current in an circuit always lags the source voltage.

A 1.2 k resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is

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

The impedance of an RL circuit varies inversely with frequency.

In an RL circuit, part of the power is resistive and part is reactive.

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

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

A power factor of 1 indicates a purely reactive circuit, and a power factor of 0 indicates a purely resistive circuit.

If a load is purely inductive and the reactive power is 12 VAR, the apparent power is

A filter passes certain frequencies and rejects others.

The power factor indicates how much of the apparent power is reactive power.

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

Which of the following power factors results in less energy loss in an RL circuit?

A 1.2 k resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is

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

A 140 resistor is in parallel with an inductor having 60 inductive reactance. Both components are across a 12 V ac source. The magnitude of the total impedance is

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

A 470 resistor and a coil with 125 inductive reactance are in parallel. Both components are across a 15 V ac voltage source. Current through the inductor is

Referring to Problem 18, the circuit impedance is

If the frequency is halved and the resistance is doubled, the impedance of a series RL circuit

To increase the current in a series RL circuit, the frequency

The voltages in Problem 5 are measured at a certain frequency. To make the resistor voltage less than the inductor voltage, the frequency is

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

In a series RL circuit, 12 V rms is measured across the resistor, and 14 V rms is measured across the inductor. The peak value of the source voltage is

A 12 k resistor is in series with a 90 mH coil across an 8 kHz ac source. Current flow in the circuit, expressed in polar form, is I = 0.30¬∞ mA. The source voltage, expressed in polar form, is

A 1.5 k resistor and a coil with a 2.2 k inductive reactance are in series across an 18 V ac source. The power factor is