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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Reduce RF current flow between pieces of equipment
C	Reduce received noise
D	Lightning protection

2. - E1A07

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

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

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	10 miles
D	3 miles

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for users of the maritime satellite service
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	All these choices are correct
D	Business-related messages for non-profit organizations

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	2 meters
C	6 meters, 2 meters, and 1.25 meters
D	6 meters and 2 meters

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Return the application document to the examinee
C	Send the application form to the FCC and inform the FCC of the grade
D	Destroy the application form

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide additional spectrum for personal use
B	To provide temporary operation while awaiting normal licensing
C	To provide for experimental amateur communications
D	To allow regular operation on Land Mobile channels

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To delay download of telemetry between satellites
B	To store digital messages in the satellite for later download by other stations
C	To upload operational software for the transponder
D	To relay messages between satellites

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	30
B	90
C	120
D	60

10. - E2C04

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

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

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	The ability to decode signals which have a very low signal-to-noise ratio
B	Permits fast-scan TV transmissions over narrow bandwidth
C	Uses only a 65 Hz bandwidth
D	Easily copied by ear if necessary

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	All these choices are correct
B	The protocol version you are using is not supported by the digital station
C	Another station you are unable to hear is using the frequency
D	Your transmit frequency is incorrect

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A slow change in the pitch of the CW signal
B	A gradual loss of signal as the sun rises
C	The returning echo is several hertz lower in frequency than the transmitted signal
D	A fluttery irregular fading

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between points at the same latitude
B	Propagation between points located on the magnetic equator
C	Propagation between a point on the equator and its antipodal point
D	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 15 percent of the distance
B	By approximately twice the distance
C	By approximately 50 percent of the distance
D	By approximately four times the distance

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S12
B	S21
C	S22
D	S11

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Reduced drift
B	Easier for front-end circuitry to eliminate image responses
C	Fewer components in the receiver
D	Improved receiver noise figure

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Squelch gain rollback
B	Quieting
C	Desensitization
D	Cross-modulation interference

20. - E4E06

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

Select	Answer
A	A loud AC hum in the audio output of your station receiver
B	A whining type noise that continually pulses off and on
C	A clicking noise at intervals of a few seconds
D	The appearance of unstable modulated or unmodulated signals at specific frequencies

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It is at a maximum
D	It is at a minimum

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	Y
B	X
C	B
D	G

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A positive magnitude
B	A positive phase angle
C	A negative phase angle
D	A negative magnitude

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	1.42 mW
B	252 W
C	355 W
D	704 W

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	P-type
B	N-type
C	Insulated gate
D	Bipolar

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	5
B	7
C	6
D	1

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To cause the output to change states continually
C	To prevent input noise from causing unstable output signals
D	To increase the sensitivity

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Generation of electrical energy in the presence of light
B	Mechanical deformation of material by the application of a magnetic field
C	Increased conductivity in the presence of light
D	Mechanical deformation of material by the application of a voltage

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Parallel wire
B	Circular waveguide
C	Miniature coax
D	Microstrip

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	12 V
B	1.5 V
C	0.5 V
D	0.1 V

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	An XOR gate
B	An OR gate
C	A flip-flop
D	A multiplexer

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Tune both the input and output for maximum power
C	Use a phase inverter in the output filter
D	Install parasitic suppressors and/or neutralize the stage

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	A filter using lattice-shaped quartz crystals for high-Q performance
B	A power supply filter made with interlaced quartz crystals
C	A filter with narrow bandwidth and steep skirts made using quartz crystals
D	An audio filter made with four quartz crystals that resonate at 1 kHz intervals

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Maximum that the output voltage may decrease at rated load
C	Maximum output voltage drops when the input voltage is varied over its specified range
D	Minimum input voltage for rated power dissipation

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By mixing signals with noise in the transition region of the diode
C	By rectification and filtering of RF signals
D	By sensing the change of reactance in the diode with respect to frequency

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	Software is converted from source code to object code during operation of the receiver
B	Incoming RF is converted to a control voltage for a voltage controlled oscillator
C	A switching mixer is used to generate I and Q signals directly from the RF input
D	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	24
C	94
D	0.21

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit consisting of a precision push-pull amplifier with a differential input
B	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
C	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
D	An electronic circuit also known as a monostable multivibrator

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A true-RMS calculating meter
B	An absorption wave meter
C	A grid dip meter
D	A D'Arsonval meter

40. - E8B01

What is the modulation index of an FM signal?

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

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

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

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

Select	Answer
A	-30 dB
B	+10 dB
C	-20 dB
D	+15 dB

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus space impedance
B	Radiation resistance plus loss resistance
C	Transmission-line resistance plus radiation resistance
D	Radiation resistance plus transmission resistance

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Azimuth
B	Radiation resistance
C	Elevation
D	Polarization

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	Additional higher vertical angle lobes will appear
B	The low-angle radiation decreases
C	The low-angle radiation increases
D	Fewer vertical angle lobes will be present

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio increases
C	The front-to-back ratio decreases
D	The frequency response is widened over the whole frequency band

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed low-impedance loads from a high-impedance source
B	It is used to feed high-impedance antennas from a low-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Higher SWR
C	Lower velocity factor
D	Smaller reflection coefficient

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical frequency
C	In fractions of transmission line electrical wavelength
D	In fractions of antenna electrical wavelength

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It adds capacitive loading, increasing the bandwidth of the antenna
B	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
C	It eliminates tracking errors caused by strong out-of-band signals
D	It increases signal strength by providing a better match to the feed line

Figure E6-2

Figure E9-2