US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
C	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
D	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Florida surrounding Cape Canaveral
B	An area surrounding the National Radio Astronomy Observatory
C	An area in Puerto Rico surrounding the Arecibo Radio Telescope
D	An area in New Mexico surrounding the White Sands Test Area

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	10 minutes
B	3 minutes
C	30 seconds
D	5 minutes

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must cease all transmissions after 5 years
B	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
C	All of these choices are correct
D	The space station must be capable of terminating transmissions by telecommand when directed by the FCC

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Employees of the VE
C	All of these choices are correct
D	Relatives of the VE as listed in the FCC rules

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1.5 kW
B	1 W
C	1.5 W
D	10 W

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To prevent the satellite from emitting out-of-band signals
B	To prevent creating errors in the satellite telemetry
C	To avoid reducing the downlink power to all other users
D	To avoid interfering with terrestrial QSOs

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Sync amplitude
B	Tone frequency
C	Tone amplitude
D	Sync frequency

9. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To allocate frequencies for DXpeditions
B	To relay calls to and from a DX station
C	To run a net to allow many stations to contact a rare DX station
D	To handle the receiving and sending of confirmation cards for a DX station

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	FSK441
B	APRS
C	Hellschreiber
D	WSPR

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	48 baud
B	110 baud
C	1200 baud
D	300 baud

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	FM
B	SSB
C	RTTY
D	CW

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
B	Long path and short path waves
C	Refracted rays and reflected waves
D	Independent waves created in the ionosphere that are elliptically polarized

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	UV emissions at 304 angstroms, correlated to solar flux index
B	The ratio of X-Ray flux to radio flux, correlated to sunspot number
C	The solar emission at 304 GHz, correlated to X-Ray flare levels
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

15. - E4A14

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It prevents oscillation in a low-frequency counter circuit
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
D	It amplifies low level signals for more accurate counting

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer
B	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
B	The ratio of atmospheric noise to phase noise
C	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network
D	The ratio of thermal noise to atmospheric noise

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To provide a range of AGC time constants
B	To allow selection of the optimum RF amplifier device
C	To increase rejection of unwanted signals
D	To store often-used frequencies

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	Nearby signals may appear to be excessively wide even if they meet emission standards
B	The audio frequency bandwidth of the received signal might be compressed
C	Received audio in the speech range might have an echo effect
D	FM signals can no longer be demodulated

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching range is increased
B	Matching bandwidth is increased
C	It has no effect on impedance matching
D	Matching bandwidth is decreased

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

Select	Answer
A	Current leads voltage by 90 degrees
B	Voltage leads current by 90 degrees
C	Voltage and current are in phase
D	Voltage and current are 180 degrees out of phase

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Faraday grid
C	Maidenhead grid
D	Rectangular coordinates

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In the same direction as the current
B	In a direction determined by the left-hand rule
C	In all directions; omni-directional
D	In a direction opposite to the current

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The frequency at which the current gain is reduced to 1
B	The breakdown voltage of the base to collector junction
C	The switching speed of the transistor
D	The change in collector current with respect to base current

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Forward DC bias current
B	Capacitance of an RF coupling capacitor
C	Reverse voltage larger than the RF signal
D	A sub-harmonic pump signal

26. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	Programmable equipment used for testing digital logic integrated circuits
B	An algorithm for simulating logic functions during circuit design
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	A device to control industrial equipment

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Electrolytic capacitors
B	Butterworth filters
C	Steel-core toroids
D	Ferrite beads

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Gallium nitride
C	Silicon
D	Silicon nitride

29. - E6F12

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Electrons
C	Photons
D	Holes

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	A flip-flop
B	An "OR" gate
C	A clock
D	An "AND" gate

31. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Reduced intermodulation products
B	Increased overall intelligibility
C	Signal inversion
D	Signal distortion and excessive bandwidth

32. - E7C03

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

Select	Answer
A	Greater transformation range
B	Greater harmonic suppression
C	Higher efficiency
D	Lower losses

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	It gives a ramp voltage at its output
B	The controlled device's duty cycle is changed to produce a constant average output voltage
C	It is generally less efficient than a linear regulator
D	The resistance of a control element is varied in direct proportion to the line voltage or load current

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce PM signals
B	By varying the tuning of a microphone preamplifier to produce AM signals
C	By varying the tuning of an amplifier tank circuit to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Add 3 to each input value and subtract 4 from each output value
B	Multiply each sample value by a factor of 3/4
C	Interpolate by a factor of three, then decimate by a factor of four
D	Change the gain by a factor of 3/4

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Increase both gain and Q
B	Restrict gain but increase Q
C	Restrict Q but increase gain
D	Restrict both gain and Q

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Using the oscillator only for CW and digital signals
B	Use of NP0 capacitors
C	Eliminating noise on the oscillator's power supply
D	Mechanically isolating the oscillator circuitry from its enclosure

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The frequency of the modulating signal
B	The amplifier gain
C	The characteristics of the modulating signal
D	The degree of carrier suppression

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the highest audio modulating frequency to the average audio modulating frequency
B	The ratio of the carrier center frequency to the audio modulating frequency
C	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Binary Coded Decimal Code
C	Gray code
D	Extended Binary Coded Decimal Interchange Code

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Repeat Request Rate (RRR)
B	Baud rate
C	Signal to noise ratio
D	Intermodulation Distortion (IMD)

42. - E9A18

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Effective radiated power
B	Power factor
C	Apparent power
D	Half-power bandwidth

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Numerical Electromagnetic Code
B	Next Element Comparison
C	Numeric Electrical Computation
D	National Electrical Code

44. - E9C13

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

Select	Answer
A	It reduces low-angle radiation
B	It reduces losses in the radiating portion of the antenna
C	It causes increased SWR
D	It changes the impedance angle of the matching network

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Greater structural strength
C	Lower Q
D	Higher losses

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The gamma match
B	The delta match
C	The stub match
D	The omega match

47. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz?

Select	Answer
A	20 meters
B	2.3 meters
C	3.5 meters
D	0.2 meters

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radio propagation
B	Antenna radiation pattern
C	Impedance along transmission lines
D	Radiation resistance

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	A fixed receiving station uses three different antennas to plot the location of the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station plots three headings to the signal source

50. - E0A08

What does SAR measure?

Select	Answer
A	Signal Amplification Rating
B	The rate at which RF energy is absorbed by the body
C	The rate of RF energy reflected from stationary terrain
D	Synthetic Aperture Ratio of the human body