MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Alternating Current and Voltage knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the magnitude of the phase angle of a 24 Vac parallel RL circuit when R = 45 and X L = 1100 ? |
| A. | 0.001° |
| B. | 2.3° |
| C. | 87.6° |
| D. | 89.9° |
| Answer» C. 87.6° | |
| 2. |
What is the true power of a 24 Vac parallel RL circuit when R = 45 and X L = 1100 ? |
| A. | 313.45 W |
| B. | 12.8 W |
| C. | 44.96 W |
| D. | 22.3 W |
| Answer» C. 44.96 W | |
| 3. |
If X L = 100 and R = 100 , then impedance will be |
| A. | 141.4 |
| B. | 14.14 |
| C. | 100 |
| D. | 200 |
| Answer» B. 14.14 | |
| 4. |
Referring to Problem 23, the reactive power is |
| A. | 10 mVAR |
| B. | 100 mVAR |
| C. | 6.76 mVAR |
| D. | 148 mVAR |
| Answer» C. 6.76 mVAR | |
| 5. |
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 | |
| 6. |
A 3.3 k 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 A |
| D. | 8.74 A |
| Answer» B. 874 mA | |
| 7. |
A 47 resistor is in series with an inductive reactance of 120 across an ac source. The impedance, expressed in polar form, is |
| A. | 47 68.6° |
| B. | 120 68.6° |
| C. | 129 31.4° |
| D. | 129 68.6° |
| Answer» E. | |
| 8. |
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 | |
| 9. |
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 | |
| 10. |
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 = 0.3 0° mA. The source voltage, expressed in polar form, is |
| A. | 3.84 20.6° V |
| B. | 12.8 20.6° V |
| C. | 0.3 20.6° V |
| D. | 13.84 69.4° V |
| Answer» B. 12.8 20.6° V | |
| 11. |
A 470 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 –76° mS |
| B. | 12.18 76° mS |
| C. | 218 –76° mS |
| D. | 12.18 –76° mS |
| Answer» E. | |
| 12. |
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 | |
| 13. |
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. | |