MCQOPTIONS
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MCQOPTIONS
This section includes 104 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
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 | |
| 52. |
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 | |
| 53. |
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 | |
| 54. |
The impedance of a series RC circuit varies directly with frequency. |
| A. | True |
| B. | False |
| Answer» C. | |
| 55. |
What is the angular difference between +j4 and -j4? |
| A. | 30° |
| B. | 90° |
| C. | 180° |
| D. | 270° |
| Answer» D. 270° | |
| 56. |
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 Ω and ∠ = -19.5° |
| B. | 707 Ω and ∠ = -19.5° |
| C. | 2121 Ω and ∠ = -19.5° |
| D. | 734 Ω and ∠ = -38.9° |
| Answer» D. 734 Ω and ∠ = -38.9° | |
| 57. |
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. | |
| 58. |
A 2 kΩ resistor and a 0.002 µF 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 | |
| 59. |
The complex number 40 ∠ 55° is equivalent to |
| A. | 55 + j55 |
| B. | 40 + j40 |
| C. | 45.88 + j65.52 |
| D. | 22.94 + j32.76 |
| Answer» E. | |
| 60. |
Total current in an RC circuit always leads the source voltage. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 61. |
In the complex plane, the number 14 - j5 is located in the Fourth quadrant |
| A. | True |
| B. | False |
| Answer» B. False | |
| 62. |
The capacitor voltage always leads the current by 90°. |
| A. | True |
| B. | False |
| Answer» C. | |
| 63. |
In an RC circuit, the impedance is determined by both the resistance and the capacitive reactance combined. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 64. |
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 | |
| 65. |
The complex number 6 + j6 is equivalent to |
| A. | 6 ∠45° |
| B. | 36 ∠45° |
| C. | 8.48 ∠45° |
| D. | 8.48 ∠90° |
| Answer» D. 8.48 ∠90° | |
| 66. |
Apparent power is expressed in watts. |
| A. | True |
| B. | False |
| Answer» C. | |
| 67. |
A positive angle of 30° is equivalent to a negative angle of |
| A. | -30° |
| B. | -330° |
| C. | -60° |
| D. | -180° |
| Answer» C. -60° | |
| 68. |
When the resistance is greater than the capacitive reactance in a series RC circuit, the phase angle is ___. |
| A. | 0° |
| B. | between 0° and 45° |
| C. | between 45° and 90° |
| D. | 45° |
| Answer» C. between 45¬∞ and 90¬∞ | |
| 69. |
If the bandwidth of an RC low-pass filter is 20 kHz, the cutoff frequency is also 20 kHz. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 70. |
The hypotenuse of the right triangle of a vector diagram for R and XC is _______________. |
| A. | impedance |
| B. | current |
| C. | voltage |
| D. | power |
| Answer» B. current | |
| 71. |
The current lags the source voltage in a series RC circuit. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 72. |
In a series RC circuit, the phase difference between the current and the source voltage _____. |
| A. | depends on the values of R and C |
| B. | equals 0° |
| C. | equals 90° |
| D. | depends on the amplitude of the input voltage |
| Answer» B. equals 0¬∞ | |
| 73. |
If the frequency increases in a parallel RC circuit, the phase angle decreases. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 74. |
The output voltage from an RC high-pass filter increases as the frequency decreases. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 75. |
If a series RC circuit contains a 120 k resistance and a 160 k capacitive reactance, the impedance equals _____. |
| A. | 280 k |
| B. | 120 k |
| C. | 160 k |
| D. | 200 k |
| Answer» E. | |
| 76. |
If the resistor drops 6 V and the capacitor drops 8 V in a series RC circuit, the source voltage equals 10 V. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 77. |
The magnitude of the impedance in the given circuit equals _____. |
| A. | 17.14 |
| B. | 24 |
| C. | 70 |
| D. | More information is needed in order to find the impedance. |
| Answer» C. 70 | |
| 78. |
When a series RC circuit is used as a low-pass filter, the output is taken from across the capacitor. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 79. |
If the frequency increases in the given circuit, how would the total current change? |
| A. | The total current would increase. |
| B. | The total current would decrease. |
| C. | The total current would remain the same. |
| D. | More information is needed in order to predict how the total current would change. |
| Answer» B. The total current would decrease. | |
| 80. |
If the impedance equals 2 k in a parallel RC circuit, the admittance equals ___. |
| A. | More information is needed in order to find the admittance. |
| B. | 2 kS |
| C. | 4 kS |
| D. | 500 µS |
| Answer» E. | |
| 81. |
The true power in the given circuit equals ___. |
| A. | 48.48 mW |
| B. | 296.93 mW |
| C. | 280.64 mW |
| D. | 96.98 mW |
| Answer» E. | |
| 82. |
The magnitude of the impedance in the given circuit is approximately 500 . |
| A. | 1 |
| B. | |
| Answer» B. | |
| 83. |
Which circuit is represented by the frequency response curve in the given figure? |
| A. | High-pass filter |
| B. | Low-pass filter |
| C. | Band-pass filter |
| D. | Band-stop filter |
| Answer» C. Band-pass filter | |
| 84. |
In parallel RC circuits, the larger the value of C, the larger the phase angle. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 85. |
What is the phase angle in the given circuit? |
| A. | 14.95° |
| B. | 36.88° |
| C. | 0° |
| D. | 90° |
| Answer» B. 36.88¬∞ | |
| 86. |
Connecting the oscilloscope as shown in the given figure will _____. |
| A. | measure the voltage across the source |
| B. | measure the voltage across C1, R2, and C2 |
| C. | short R1 |
| D. | short C1, R2, and C2 |
| Answer» E. | |
| 87. |
Which statement about a series RC circuit is true? |
| A. | The capacitor's voltage drop is in phase with the resistor's voltage drop. |
| B. | The current leads the source voltage. |
| C. | The current lags the source voltage. |
| D. | The resistor voltage lags the current. |
| Answer» C. The current lags the source voltage. | |
| 88. |
If the given circuit is used as a filter, the cutoff frequency is _____. |
| A. | 5 kHz |
| B. | 14.47 kHz |
| C. | less than 5 kHz |
| D. | more than 20 kHz |
| Answer» C. less than 5 kHz | |
| 89. |
Resistance is the same as impedance in an RC circuit. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 90. |
In a series RC circuit, the phase difference between the capacitor and the resistor voltages ___. |
| A. | depends on the values of R and C |
| B. | equals 0° |
| C. | equals 90° |
| D. | depends on the value of the input voltage |
| Answer» D. depends on the value of the input voltage | |
| 91. |
What is the phase angle for a parallel circuit consisting of a 500 kHz, 5 Vac source with a 47 pF capacitor, and a 4.7 k resistor in parallel? |
| A. | 55.3° |
| B. | –55.3° |
| C. | 34.8° |
| D. | –34.8° |
| Answer» D. ‚Äì34.8¬∞ | |
| 92. |
What is the effect of increasing the resistance in a series RC circuit? |
| A. | There will be no effect at all. |
| B. | The current will increase. |
| C. | The phase shift will decrease. |
| D. | The input voltage will increase. |
| Answer» D. The input voltage will increase. | |
| 93. |
What is the total current in the given circuit? |
| A. | 0.28 A |
| B. | 0.399 A |
| C. | 909 A |
| D. | 0.2 A |
| Answer» B. 0.399 A | |
| 94. |
If a 100 resistance is connected to a 100 capacitive reactance in a series RC circuit, the impedance equals 200 . |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» C. 1 | |
| 95. |
______________ is shuttled back and forth between the source and load. |
| A. | True power |
| B. | Reactive power |
| C. | Apparent power |
| D. | Impedance power |
| Answer» C. Apparent power | |
| 96. |
In a purely capacitive ac circuit, the amount of energy converted to heat is proportional to the circuit's current. |
| A. | 1 |
| B. | |
| Answer» C. | |
| 97. |
Calculate the phase angle in the given circuit. |
| A. | 0° |
| B. | 90° |
| C. | 22.52° |
| D. | 67.48° |
| Answer» E. | |
| 98. |
What is the current through XC1 in the given circuit? |
| A. | 32.2 mA |
| B. | 16 mA |
| C. | 12 mA |
| D. | 48 mA |
| Answer» B. 16 mA | |
| 99. |
A 10 k capacitive reactance equals a 100 µS capacitive susceptance. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 100. |
The phase angle in the given circuit equals___. |
| A. | 90° |
| B. | 36.87° |
| C. | 0° |
| D. | 53.13° |
| Answer» C. 0¬∞ | |