US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
B	Only commercial transmitters
C	Only the most powerful transmitter
D	Each transmitter operating with a duty cycle greater than 50 percent

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

Select	Answer
A	1 watt EIRP (Equivalent isotropic radiated power)
B	50 watts PEP
C	5 watts EIRP (Equivalent isotropic radiated power)
D	100 watts PEP

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	15 kHz
B	10 kHz
C	20 kHz
D	3 kHz

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	60 Hz
B	1.5 kHz
C	2.8 kHz
D	170 Hz

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
B	Any amateur station, subject to the privileges of the class of operator license held by the control operator
C	Only those of Amateur Extra Class operators
D	Only those of General, Advanced or Amateur Extra Class operators

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
C	They must collect and send the documents to the NCVEC for grading
D	They must collect and submit the documents to the coordinating VEC for grading

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
B	All these choices are correct
C	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
D	The transmission must not be used to obscure the meaning of any communication

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	An isotropic antenna
B	A circularly polarized antenna
C	A log-periodic dipole array
D	A linearly polarized antenna

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Hue
C	Spectral intensity
D	Luminance

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

Select	Answer
A	The 60 meter band channel centered on 5373 kHz
B	Cable TV channels 41 through 43
C	HF frequencies where digital communications are permitted
D	Frequencies shared with various unlicensed wireless data services

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Doppler shift of beacon signals
B	Bandwidth compressed LORAN
C	Ultrasonics
D	APRS

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	300 baud packet
C	PSK31
D	AMTOR

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	The jet stream
B	Wind shear
C	Dust devil
D	Temperature inversion

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Late at night
B	Morning
C	Noon
D	Afternoon or early evening

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Circular
B	Horizontal
C	Elliptical
D	Vertical

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	All these choices are correct
C	Antenna analyzers do not need an external RF source
D	Antenna analyzers display a time-varying representation of the modulation envelope

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Relative quality of the data
C	Frequency order of the measurements
D	The port or ports at which measurements are made

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It can combine with strong signals on nearby frequencies to generate interference
B	It can affect the receiver's frequency calibration
C	It limits the receiver's ability to receive strong signals
D	It decreases receiver third-order intercept point

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
B	When the signals from the transmitters are reflected in phase from airplanes passing overhead
C	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
D	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that are constant at all IF levels
B	Signals that appear at one IF but not another
C	Signals that have a sharply peaked frequency distribution
D	Signals that appear across a wide bandwidth

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

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

22. - E5B09

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

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

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On the vertical axis
B	On a horizontal line, offset vertically above the horizontal axis
C	On a line through the origin, slanted at 45 degrees
D	On the horizontal axis

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
C	Thermal effects on the surface of the conductor decrease the impedance
D	Thermal effects on the surface of the conductor increase the impedance

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
B	Base-to-emitter resistance of approximately 6 to 7 ohms
C	Base-to-emitter voltage of approximately 6 to 7 volts
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Inductive bias
B	Reverse bias
C	Forward bias
D	Zero bias

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

Select	Answer
A	2
B	3
C	4
D	1

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids generally have better temperature stability
B	Ferrite toroids generally have lower initial permeability
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally require fewer turns to produce a given inductance value

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	50 ohms
B	450 ohms
C	10 ohms
D	300 ohms

30. - E6F03

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

Select	Answer
A	A lens and a photomultiplier
B	An amplitude modulated helium-neon laser
C	A frequency modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It produces 10 output pulses for every input pulse
C	It produces one output pulse for every 10 input pulses
D	It decodes a decimal number for display on a seven-segment LED display

32. - E7B11

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

Select	Answer
A	Output load resistor
B	Self bias
C	Fixed bias
D	Emitter bypass

33. - E7C03

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

Select	Answer
A	Greater harmonic suppression
B	Higher efficiency
C	Greater transformation range
D	Does not require a capacitor

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery damage due to overcharge
B	Matching of day and night charge rates
C	Prevention of battery undercharge
D	Control of electrolyte levels during battery discharge

35. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A balanced modulator on the audio amplifier
B	A balanced modulator on the oscillator
C	A reactance modulator on the oscillator
D	A reactance modulator on the final amplifier

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At least half the rate of the highest frequency component of the signal
B	At least twice the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

37. - E7G02

What is ringing in a filter?

Select	Answer
A	An echo caused by a long time delay
B	Partial cancellation of the signal over a range of frequencies
C	Undesired oscillations added to the desired signal
D	A reduction in high frequency response

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Toroidal inductors
B	Wirewound resistors
C	Non-inductive resistors
D	NP0 capacitors

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Vector analysis
B	Numerical analysis
C	Fourier analysis
D	Differential analysis

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The type of modulation used by the transmitter
B	The ratio of frequency deviation to modulating signal frequency
C	The bandwidth of the transmitted signal divided by the modulating signal frequency
D	The ratio of modulating signal amplitude to frequency deviation

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	It is impossible
B	Using a more efficient digital code
C	Increasing analog-to-digital conversion resolution
D	Using forward error correction

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Reduce keying waveform rise and fall times
B	Increase keying waveform rise and fall times
C	High-pass filters at the transmitter output
D	Low-pass filters at the transmitter output

43. - E9A13

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

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

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave current generator
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a series of segments, each having a uniform value of current
D	A wire is modeled as a single sine-wave voltage source

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It reflects the standing waves on the antenna elements back to the transmitter
B	It decreases the ground loss
C	It changes the radiation pattern from bidirectional to unidirectional
D	It changes the radiation pattern from horizontal to vertical polarization

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is unchanged if the loading coil is located at a voltage maximum point
B	It is decreased
C	It is increased
D	It is unchanged if the loading coil is located at the feed point

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	75 ohms
B	450 ohms
C	62 ohms
D	50 ohms

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very high impedance
B	The same as the generator output impedance
C	Very low impedance
D	The same as the characteristic impedance of the transmission line

49. - E9G06

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

Select	Answer
A	Prime axis
B	Polar axis
C	Reactance axis
D	Impedance axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To compensate for isotropic directivity and the antenna effect of feed lines
B	To prevent receiver overload which reduces pattern nulls
C	To narrow the receiver bandwidth
D	To increase receiver sensitivity

Figure E6-3

Figure E7-1

Figure E9-3