Explore topic-wise MCQs in Electrical Engineering.

This section includes 28 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.

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

A. True
B. False
Answer» C.
2.

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
3.

A 470 Ω resistor and a 200 mH coil are in parallel. Both components are across a 1.5 kHz ac source. The total admittance of the circuit, in polar form, is%!

A. 12.60 ‚Äö√ ‚Ä -76¬¨‚àû mS
B. 12.18 ‚Äö√ ‚Ä 76¬¨‚àû mS
C. 218 ‚Äö√ ‚Ä -76¬¨‚àû mS
D. 12.18 ‚Äö√ ‚Ä -76¬¨‚àû mS
Answer» E.
4.

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.
5.

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

A. True
B. False
Answer» B. False
6.

The impedance of an RL circuit varies inversely with frequency.%!

A. True
B. False
Answer» C.
7.

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
8.

When the frequency of the voltage applied to a series RL 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
9.

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

A. True
B. False
Answer» C.
10.

A filter passes certain frequencies and rejects others.%!

A. True
B. False
Answer» B. False
11.

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

A. True
B. False
Answer» C.
12.

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.
13.

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
14.

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

A. True
B. False
Answer» C.
15.

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

A. 5.51 Ω
B. 55.15 Ω
C. 90 Ω
D. 200 Ω
Answer» C. 90 ≈í¬©
16.

A 470 Ω resistor and a coil with 125 Ω 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.
17.

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

A. True
B. False
Answer» B. False
18.

A 3.3 kΩ resistor and a 120 mH coil are in parallel. Both components are across a 2 kHz, 12 V ac source. The total current in the circuit is%!

A. 8.74 mA
B. 874 mA
C. 874 µA
D. 8.74 µA
Answer» B. 874 mA
19.

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
20.

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

A. True
B. False
Answer» B. False
21.

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

A. True
B. False
Answer» B. False
22.

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
23.

A 1.5 kΩ resistor and a coil with a 2.2 kΩ 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
24.

*/*_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
25.

_ A 47 Ω resistor is in series with an inductive reactance of 120 Ω across an ac source. The impedance, expressed in polar form, is$?

A. 47 ‚Äö√ ‚Ä 68.6¬¨‚àû ≈í¬©
B. 120 ‚Äö√ ‚Ä 68.6¬¨‚àû ≈í¬©
C. 129 ‚Äö√ ‚Ä 31.4¬¨‚àû ≈í¬©
D. 129 ‚Äö√ ‚Ä 68.6¬¨‚àû ≈í¬©
Answer» E.
26.

A 12 k≈í¬© 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 = 0.3 ‚Äö√ ‚Ä 0¬¨‚àû mA. The source voltage, expressed in polar form, is$?

A. 3.84 ‚Äö√ ‚Ä 20.6¬¨‚àû V
B. 12.8 ‚Äö√ ‚Ä 20.6¬¨‚àû V
C. 0.3 ‚Äö√ ‚Ä 20.6¬¨‚àû V
D. 13.84 ‚Äö√ ‚Ä 69.4¬¨‚àû V
Answer» B. 12.8 ‚Äö√ ‚Ä 20.6¬¨‚àû V
27.

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
28.

A 1.2 kΩ 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 Ω
B. 1,526 Ω
C. 1,200 Ω
D. 942 Ω
Answer» C. 1,200 ≈í¬©