Practice Exam

Element 4: Extra

E7G03

1. Which of the following is an advantage of using an op-amp instead of LC elements in an audio filter?

E7A12

2. What is the name for logic which represents a logic "0" as a high voltage?

E7E03

3. How does an analog phase modulator function?

E3A10

4. Which of the following is a good technique for making meteor-scatter contacts?

E9B09

5. What type of computer program technique is commonly used for modeling antennas?

E2A05

6. What do the letters in a satellite's mode designator specify?

E7F11

7. What is an advantage of a period-measuring frequency counter over a direct-count type?

E3C01

8. Which of the following effects does Aurora activity have on radio communications?

E0A06

9. Why are there separate electric (E) and magnetic (H) field MPE limits?

E6D05

10. What is a liquid-crystal display (LCD)?

E4C07

11. What does the MDS of a receiver represent?

E5B11

12. What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

E6B02

13. What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

E1A05

14. What is the maximum power output permitted on the 60 meter band?

E9A13

15. How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

E2E08

16. Which of the following HF digital modes can be used to transfer binary files?

E1C04

17. When may an automatically controlled station retransmit third party communications?

E7C03

18. What advantage does a Pi-L-network have over a Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Figure

E7B11

19. In Figure E7-1, what is the purpose of R3?

E1D03

20. What is a telecommand station in the amateur satellite service?

E1E03

21. What is a Volunteer Examiner Coordinator?

E5C01

22. In polar coordinates, what is the impedance of a network consisting of a 100-ohm-reactance inductor in series with a 100-ohm resistor?

E6E05

23. Which of the following noise figure values is typical of a low-noise UHF preamplifier?

E4D14

24. Which of the following is a way to reduce the likelihood of receiver desensitization?

E5D11

25. What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

E9C13

26. What is the main effect of placing a vertical antenna over an imperfect ground?

E9H12

27. What is an advantage of using a shielded loop antenna for direction finding?

E4B11

28. How should a portable antenna analyzer be connected when measuring antenna resonance and feed point impedance?

E9E01

29. What system matches a high-impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Figure

E9G06

30. On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

E4A12

31. Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

E3B09

32. At what time of day is gray-line propagation most likely to occur?

E6C03

33. Which of the following describes tri-state logic?

E7H02

34. What condition must exist for a circuit to oscillate?

E2D06

35. Which of the following is a commonly used 2-meter APRS frequency?

E5A12

36. What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

E2C10

37. Why might a DX station state that they are listening on another frequency?

E1B06

38. Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

E7D17

39. What is the primary reason that a high-frequency inverter type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

E6F03

40. What is the most common configuration of an optoisolator or optocoupler?

E4E14

41. What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

E2B17

42. What is the approximate bandwidth of a slow-scan TV signal?

E9D14

43. Which of the following types of conductor would be best for minimizing losses in a station's RF ground system?

E1F12

44. Who may be the control operator of an auxiliary station?

E8B07

45. When using a pulse-width modulation system, why is the transmitter's peak power greater than its average power?

E8A02

46. What type of wave has a rise time significantly faster than its fall time (or vice versa)?

E8D15

47. Which of the following is a typical value for the RMS voltage at a standard U.S. household electrical power outlet?

E9F15

48. What impedance does a 1/2-wavelength transmission line present to a generator when the line is open at the far end?

E6A06

49. What is the beta of a bipolar junction transistor?

E8C13

50. What is one advantage of using JT-65 coding?