MCQOPTIONS
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MCQOPTIONS
This section includes 37 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. |
In a lag network, the output voltage lags the input voltage in phase.~! |
| A. | True |
| B. | False |
| Answer» B. False | |
| 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. | |
| 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 | |
| 4. |
Complex numbers can be added and subtracted but not multiplied or divided.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 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 | |
| 6. |
A 120 Ω resistor is in parallel with a capacitor with a capacitive reactance of 40 Ω. Both components are across a 12 V ac source. What is the magnitude of the total impedance?%! |
| A. | 37.9 Ω |
| B. | 3.7 Ω |
| C. | 14,400 Ω |
| D. | 4,800 Ω |
| Answer» B. 3.7 ≈í¬© | |
| 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 | |
| 8. |
An imaginary number is one that exists only in the mind of the mathematician.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 9. |
The polar form of a complex number consists of a real part and a j part.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 10. |
The resistor voltage is always out of phase with the current.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 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 | |
| 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 | |
| 13. |
A 12 kŒ© 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 ‚à †0¬∞ 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. | |
| 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. | |
| 15. |
A complex number represents a phasor quantity.%! |
| A. | True |
| B. | False |
| Answer» B. False | |
| 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 | |
| 17. |
The complex number 6 + j6 is equivalent to%! |
| A. | 6 ‚à †45¬∞ |
| B. | 36 ‚à †45¬∞ |
| C. | 8.48 ‚à †45¬∞ |
| D. | 8.48 ‚à †90¬∞ |
| Answer» D. 8.48 ‚Äö√ ‚Ä 90¬¨‚àû | |
| 18. |
A capacitor with 150 Ω of capacitive reactance is across an ac source. The impedance, expressed in polar form, is%! |
| A. | Z = 150 |
| B. | Z = 150 ‚à †90¬∞O |
| C. | Z = 150 ‚à †-90¬∞O |
| D. | Z = 150 ‚à †180¬∞O |
| Answer» D. Z = 150 ‚Äö√ ‚Ä 180¬¨‚àûO | |
| 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 | |
| 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 | |
| 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. | |
| 22. |
Apparent power is expressed in watts.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 23. |
The circuit phase angle is the angle between the total current and the applied (source) voltage.%! |
| A. | True |
| B. | False |
| Answer» B. False | |
| 24. |
A 47 Ω resistor and a capacitor with a capacitive reactance of 120 Ω are in series across an ac source. What is the circuit impedance, Z?%! |
| A. | 129 Ω |
| B. | 12.9 Ω |
| C. | 167 Ω |
| D. | 73 Ω |
| Answer» B. 12.9 ≈í¬© | |
| 25. |
A 470 Ω 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 Ω |
| B. | 2.12 mS + j3.14 mS |
| C. | 3.14 mS + j2.12 mS |
| D. | 318.3 Ω |
| Answer» C. 3.14 mS + j2.12 mS | |
| 26. |
A filter passes all frequencies.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 27. |
A positive angle of 30° is equivalent to a negative angle of%! |
| A. | -30° |
| B. | -330° |
| C. | -60° |
| D. | -180° |
| Answer» C. -60¬¨‚àû | |
| 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 | |
| 29. |
A 47 Ω resistor and a capacitor with 150 Ω of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is%! |
| A. | Z = 47 Ω + j150 Ω |
| B. | Z = 47 Ω - j150 Ω |
| C. | Z = 197 Ω |
| D. | Z = 103 Ω |
| Answer» C. Z = 197 ≈í¬© | |
| 30. |
The impedance of a series RC circuit varies directly with frequency.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 31. |
The power factor (PF) indicates how much of the apparent power is true power.%! |
| A. | True |
| B. | False |
| Answer» B. False | |
| 32. |
What is the angular difference between +j4 and -j4?%! |
| A. | 30° |
| B. | 90° |
| C. | 180° |
| D. | 270° |
| Answer» D. 270¬¨‚àû | |
| 33. |
A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 kΩ. Current flow in the circuit is%! |
| A. | 9.2 mA |
| B. | 92 mA |
| C. | 4.6 mA |
| D. | 460 mA |
| Answer» D. 460 mA | |
| 34. |
A 2 kΩ 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 Œ© and ‚à †= -19.5¬∞ |
| B. | 707 Œ© and ‚à †= -19.5¬∞ |
| C. | 2121 Œ© and ‚à †= -19.5¬∞ |
| D. | 734 Œ© and ‚à †= -38.9¬∞ |
| Answer» D. 734 ≈í¬© and ‚Äö√ ‚Ä = -38.9¬¨‚àû | |
| 35. |
An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45°, the following condition must exist:%! |
| A. | R = XC |
| B. | R > XC |
| C. | R < XC |
| D. | R = 5XC |
| Answer» D. R = 5XC | |
| 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. | |
| 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 | |