# ELECTRICAL ENGINEERING

Questions 1 to 25: Select the best answer to each question. Note that a question and its answers may be split across a page break, so be sure that you have seen the entire question and all the answers before choosing an answer.

1. A 10 mH inductor and a 100 Ω resistor are connected in parallel. The circuit is supplied with 24 VAC at 2000 Hz. What is the impedance (rounded) of the circuit? A. 57.38 Ω B. 78.23 Ω C. 108.71 Ω D. 98.16 Ω

2. A circuit contains a 60 mH and a 40 mH inductor connected in parallel. The circuit has a source voltage of 100 VAC and a frequency of 1000 Hz. What is the total inductive reactance (rounded) of the circuit? A. 173 Ω B. 194 Ω C. 212 Ω D. 151 Ω

3. What is the total inductive reactance in the circuit shown in the figure? A. 100.48 Ω B. 60.29 Ω C. 16 Ω D. 48.2 Ω 4. What is the total circuit current shown in the figure? A. 3.5 A B. 0.28 A C. 0.75 A D. 2.5 A

5. A 100 mH inductor is placed in parallel with a 100 Ω resistor in a circuit. The circuit has a source voltage of 30 VAC and a frequency of 200 Hz. What is the current through the inductor (rounded)? A. 0.42 A B. 0.24 A C. 0.36 A D. 0.48 A

6. What is the total inductance of the circuit shown in the figure? A. 0.48 H B. 0.16 H C. 0.63 H D. 1.0 H 7. What is the time constant of a 20 mH inductor in series with a 230 Ω resistor? A. 86.96 s B. 86.96 μs C. 900 ms D. 0.09 s

8. Which of the following denotes inductive reactance? A. XL B. Z C. R D. H

9. A 10 mH inductor and a 100 Ω resistor are connected in parallel. The circuit is supplied with 24 VAC at 2000 Hz. What is the phase angle (rounded) of this circuit? A. 49.2° B. 28.2° C. 24.6° D. 38.4°

10. What is the impedance of the circuit shown in the figure? A. 60.23 Ω B. 285.15 Ω C. 141.76 Ω D. 70.88 Ω 11. A 10 mH inductor and a 100 Ω resistor are connected in parallel. The circuit is supplied with 24 VAC at 2000 Hz. What is the inductive reactance of the inductor? A. 386.2 Ω B. 226.4 Ω C. 125.6 Ω D. 442.6 Ω 12. What is the inductive reactance of a 2 H inductor in a 60 Hz, AC circuit? A. 0.08 Ω B. 948 Ω C. 753.60 Ω D. 120 Ω 13. What is the inductive reactance of a 0.5 H inductor at a frequency of 1.985 kHz? A. 5024 Ω B. 2234 Ω C. 800 Ω D. 6228 Ω

14. Which of the following denotes impedance? A. H B. Z C. XL D. R 15. What is the parallel impedance of the circuit shown in the figure? A. 64.9 Ω B. 38.3 Ω C. 100 Ω D. 32.65 Ω 16. What is the total current (IT ) of the circuit shown in the figure? A. 1.71 A B. 1.31 A C. 1.50 A D. 0.88 A 17. A 6 mH, a 2 mH, and a 10 mH inductor are placed in series with a 1000 Ω resistor in a circuit. The circuit has a source voltage of 60 VAC at 1000 Hz. What is the total inductive reactance of this circuit? A. 93.80 Ω B. 86.42 Ω C. 113.04 Ω D. 121.64 Ω 18. What is the inductive reactance of a 2 mH inductor at a frequency of 1000 Hz? A. 20.25 Ω B. 12.56 Ω C. 68.3 Ω D. 204.4 Ω 19. A series circuit contains a 30 mH inductor and a 200 Ω resistor. What is the total circuit current (rounded) if the applied voltage is 60 V and the frequency is 1000 Hz? A. 0.22 A B. 0.84 A C. 1.24 A D. 0.44 A

20. What is the inductive reactance of a 0.5 H inductor connected with a 1000 Ω resistor in an AC circuit supplied with 48 VAC at 100 Hz? A. 150.72 Ω B. 314 Ω C. 0.31 Ω D. 500 Ω

21. A parallel circuit has a resistance of 280 Ω and an inductive reactance of 360 Ω. What is this circuit’s impedance? A. 221.02 Ω B. 540 Ω C. 368 Ω D. 191.80 Ω

22. What is the time constant of a 2 mH inductor placed in series with a 400 Ω resistor? A. 0.8 s B. 5 μs C. 0.6 s D. 5 ms 23. What is the inductive reactance of the circuit shown in the figure? A. 41.45 Ω B. 34.54 Ω C. 6.91 Ω D. 41,448 Ω

24. If an 80 mH inductor is in series with a 220 Ω resistor in a circuit with a source frequency of 1000 Hz, what will be the phase angle (rounded) of the current with respect to the voltage? A. 66° B. 70° C. 48° D. 50° End of exam 25. What is the current through the inductor shown in the figure? A. 1.45 A B. 1.21 A C. 0.450 A D. 450.50 A