MCQOPTIONS
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MCQOPTIONS
This section includes 73 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
What is the angular difference between +j4 and –j4? |
| A. | 30° |
| B. | 90° |
| C. | 180° |
| D. | 270° |
| Answer» D. 270¬∞ | |
| 52. |
A 120 resistor is in parallel with a capacitor with a capacitive reactance of 40 . Both components are across a 12 V ac source. What is the magnitude of the total impedance? |
| A. | 37.9 |
| B. | 3.7 |
| C. | 14400 |
| D. | 4800 |
| Answer» B. 3.7 | |
| 53. |
In an RC circuit, the impedance is determined by both the resistance and the capacitive reactance combined. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 54. |
The power factor (PF) indicates how much of the apparent power is true power. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 55. |
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. | |
| 56. |
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 | |
| 57. |
A 47 resistor and a capacitor with 150 of capacitive reactance are in series across an ac source. The impedance, expressed in rectangular form, is |
| A. | Z = 47 + j150 |
| B. | Z = 47 – j150 |
| C. | Z = 197 |
| D. | Z = 103 |
| Answer» C. Z = 197 | |
| 58. |
The voltages in Problem 4 are measured at a certain frequency. To make the capacitor voltage greater than the resistor voltage, the frequency |
| A. | must be increased |
| B. | must be decreased |
| C. | is held constant |
| D. | has no effect |
| Answer» C. is held constant | |
| 59. |
A 2 k resistor is in series with a 0.015 F capacitor across a 15 kHz ac source. What is the magnitude of the total impedance and the phase angle? |
| A. | 73.4 and θ = –19.5° |
| B. | 707 and θ = –19.5° |
| C. | 2121 and θ = –19.5° |
| D. | 734 and θ = –38.9° |
| Answer» D. 734 and Œ∏ = ‚Äì38.9¬∞ | |
| 60. |
A 2 k resistor and a 0.002 F capacitor are in series across an ac source. Current in the circuit is 6.50 mA. The true power is |
| A. | 84.5 mW |
| B. | 845 mW |
| C. | 13 mW |
| D. | 130 mW |
| Answer» B. 845 mW | |
| 61. |
A 47 resistor and a capacitor with a capacitive reactance of 120 are in series across an ac source. What is the circuit impedance, Z? |
| A. | 129 |
| B. | 12.9 |
| C. | 167 |
| D. | 73 |
| Answer» B. 12.9 | |
| 62. |
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 | |
| 63. |
A positive angle of 30° is equivalent to a negative angle of |
| A. | –30° |
| B. | –330° |
| C. | –60° |
| D. | –180° |
| Answer» C. ‚Äì60¬∞ | |
| 64. |
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 | |
| 65. |
A 470 resistor and a 0.2 F capacitor are in parallel across a 2.5 kHz ac source. The admittance, Y, in rectangular form, is |
| A. | 212 |
| B. | 2.12 mS + j3.14 mS |
| C. | 3.14 mS + j2.12 mS |
| D. | 318.3 |
| Answer» C. 3.14 mS + j2.12 mS | |
| 66. |
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. | |
| 67. |
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 | |
| 68. |
A capacitor with 150 of capacitive reactance is across an ac source. The impedance, expressed in polar form, is |
| A. | Z = 150 |
| B. | Z = 15090° |
| C. | Z = 150 –90° |
| D. | Z = 150180° |
| Answer» D. Z = 150180¬∞ | |
| 69. |
A 12 k resistor is in series with a 0.02 F capacitor across a 1.2 kHz ac source. If the current is expressed in polar form as I = 0.30° 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. | |
| 70. |
A complex number represents a phasor quantity. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 71. |
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 | |
| 72. |
A resistor and a capacitor are in series across a 20 V ac source. Circuit impedance is 4.33 k. Current flow in the circuit is |
| A. | 9.2 mA |
| B. | 92 mA |
| C. | 4.6 mA |
| D. | 460 mA |
| Answer» D. 460 mA | |
| 73. |
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. | |