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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?

SelectAnswer
AOnly the most powerful transmitter
BOnly commercial transmitters
CEach transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
DEach transmitter operating with a duty cycle greater than 50 percent

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

SelectAnswer
AAny FCC-issued amateur license
BAny amateur license with an FCC Marine or Aircraft endorsement
CAn unrestricted Radiotelephone Operator Permit
DOnly General Class or higher amateur licenses

3. - E1B01

Which of the following constitutes a spurious emission?

SelectAnswer
AAn amateur station transmission made without the proper call sign identification
BA signal transmitted to prevent its detection by any station other than the intended recipient
CAn emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
DAny transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C08

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

SelectAnswer
A3 minutes
B30 seconds
C5 minutes
D10 minutes

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A70 cm and 33 cm
B70 cm only
C70 cm and 13 cm
D33 cm and 13 cm

6. - E1E12

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

SelectAnswer
AMaintain the application form with the VEC's records
BSend the application form to the FCC and inform the FCC of the grade
CDestroy the application form
DReturn the application document to the examinee

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

SelectAnswer
A420 MHz - 430 MHz
B222 MHz - 223 MHz
C440 MHz - 450 MHz
D53 MHz - 54 MHz

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

SelectAnswer
AWhich sideband to use
BThe 23 centimeter and 13 centimeter bands
CFM and Digital Store-and-Forward systems
DThe 2 meter and 70 centimeter bands

9. - E2B07

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

SelectAnswer
ASpectral intensity
BLuminance
CHue
DChroma

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

SelectAnswer
AContacts using tactical call signs
BSpecial event contacts between stations in the U.S.
CRepeater contacts between U.S. club members
DContacts between a U.S. station and a non-U.S. station

11. - E2D06

Which of the following describes a method of establishing EME contacts?

SelectAnswer
AHigh-speed CW identification to avoid fading
BJudging optimum transmission times by monitoring beacons reflected from the moon
CTime synchronous transmissions alternately from each station
DStoring and forwarding digital messages

12. - E2E12

How do ALE stations establish contact?

SelectAnswer
AALE radios send a constant tone code to establish a frequency for future use
BALE radios activate when they hear their signal echoed by back scatter
CALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
DALE radios monitor an internet site for the frequency they are being paged on

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

SelectAnswer
A5000 miles, if the moon is at perigee
B12,000 miles, if the moon is visible by both stations
C2000 miles, if the moon is at apogee
D500 miles, if the moon is at perigee

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
A160 meters to 10 meters
B6 meters to 2 meters
COnly 30 meters to 10 meters
DOnly 160 meters to 40 meters

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

SelectAnswer
AIt increases
BIt peaks at roughly 14 MHz
CIt decreases
DIt stays the same

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

SelectAnswer
ALogic analyzer
BModulation monitor
CNetwork analyzer
DBit error rate tester

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

SelectAnswer
AInput attenuator accuracy
BTime base accuracy
CTemperature coefficient of the logic
DDecade divider accuracy

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

SelectAnswer
AThe noise figure of a 1 Hz bandwidth receiver
BThe theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
CThe minimum detectable signal as a function of receive frequency
DThe galactic noise contribution to minimum detectable signal

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

SelectAnswer
AA properly terminated circulator at the output of the repeater's transmitter
BUtilizing a Class C final amplifier
CUtilizing a Class D final amplifier
DA band-pass filter in the feed line between the transmitter and receiver

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

SelectAnswer
ABy installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
BBy installing a noise suppression resistor and a blocking capacitor in both leads
CBy installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
DBy connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

21. - E5A04

What is the magnitude of the impedance of a parallel RLC circuit at resonance?

SelectAnswer
AApproximately equal to circuit resistance
BApproximately equal to inductive reactance
CLow compared to the circuit resistance
DHigh compared to the circuit resistance

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

SelectAnswer
A14.0 degrees with the voltage lagging the current
B68.2 degrees with the voltage leading the current
C68.2 degrees with the voltage lagging the current
D14.0 degrees with the voltage leading the current

23. - E5C03

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

SelectAnswer
AA negative phase angle
BA positive magnitude
CA negative magnitude
DA positive phase angle

24. - E5D11

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

SelectAnswer
A1.414
B1.73
C0.5
D0.866

25. - E6A07

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

SelectAnswer
ABase-to-emitter voltage of approximately 0.6 to 0.7 volts
BBase-to-emitter resistance of approximately 6 to 7 ohms
CBase-to-emitter voltage of approximately 6 to 7 volts
DBase-to-emitter resistance of approximately 0.6 to 0.7 ohms

26. - E6B09

What is a common use for point-contact diodes?

SelectAnswer
AAs a high-voltage rectifier
BAs an RF detector
CAs a constant voltage source
DAs a constant current source

27. - E6C01

What is the function of hysteresis in a comparator?

SelectAnswer
ATo cause the output to change states continually
BTo prevent input noise from causing unstable output signals
CTo allow the comparator to be used with AC input signals
DTo increase the sensitivity

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

SelectAnswer
APowdered iron
BFerrite
CBrass
DCeramic

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

SelectAnswer
AShorter circuit-board traces
BAll these choices are correct
CSmaller circuit area
DComponents have less parasitic inductance and capacitance

30. - E6F07

What is a solid-state relay?

SelectAnswer
AA semiconductor passive delay line
BA mechanical relay that latches in the on or off state each time it is pulsed
CA device that uses semiconductors to implement the functions of an electromechanical relay
DA relay using transistors to drive the relay coil

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
APositive Logic
BAssertive Logic
CReverse Logic
DNegative logic

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

SelectAnswer
ABecause they maintain the sidebands, thus causing multiple duplicate signals
BBecause they invert the sidebands causing distortion
CBecause they are relatively far in frequency from the desired signal
DBecause they are relatively close in frequency to the desired signal

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
AA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
BTwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
CAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
DTwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

SelectAnswer
AIt provides negative feedback to improve regulation
BIt provides D1 with current
CIt controls the current supplied to the load
DIt provides a constant load for the voltage source

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

SelectAnswer
AA pre-emphasis network
BA heterodyne suppressor
CA de-emphasis network
DA heterodyne enhancer

36. - E7F01

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

SelectAnswer
AIncoming RF is converted to a control voltage for a voltage controlled oscillator
BSoftware is converted from source code to object code during operation of the receiver
CIncoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
DA switching mixer is used to generate I and Q signals directly from the RF input

37. - E7G03

What is the typical input impedance of an op-amp?

SelectAnswer
A1000 ohms
BVery low
C100 ohms
DVery high

38. - E7H02

What is a microphonic?

SelectAnswer
ADistortion caused by RF pickup on the microphone cable
BChanges in oscillator frequency due to mechanical vibration
CAn IC used for amplifying microphone signals
DExcess loading of the microphone by an oscillator

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

SelectAnswer
AA square wave
BA sine wave
CA sawtooth wave
DA cosine wave

40. - E8B11

What is digital time division multiplexing?

SelectAnswer
ATwo or more signals are quadrature modulated to increase bandwidth efficiency
BTwo or more data streams share the same channel by transmitting time of transmission as the sub-carrier
CTwo or more signals are arranged to share discrete time slots of a data transmission
DTwo or more data streams are assigned to discrete sub-carriers on an FM transmitter

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

SelectAnswer
A26 Hz
B104 Hz
C13 Hz
D52 Hz

42. - E8D11

What is one advantage of using ASCII code for data communications?

SelectAnswer
AIt includes built-in error correction features
BIt contains fewer information bits per character than any other code
CIt is possible to transmit both upper and lower case text
DIt uses one character as a shift code to send numeric and special characters

43. - E9A13

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

SelectAnswer
APower factor
BHalf-power bandwidth
CApparent power
DEffective radiated power

44. - E9B10

What is the principle of a Method of Moments analysis?

SelectAnswer
AA wire is modeled as a single sine-wave current generator
BA wire is modeled as a single sine-wave voltage source
CA wire is modeled as a series of segments, each having a distinct value of voltage across it
DA wire is modeled as a series of segments, each having a uniform value of current

45. - E9C09

Which of the following describes a G5RV antenna?

SelectAnswer
AA wide band dipole using shorted coaxial cable for the radiating elements and fed with a4:1 balun
BA multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
CA multi-band trap antenna
DA phased array antenna consisting of multiple loops

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

SelectAnswer
ANear the center of the vertical radiator
BAs low as possible on the vertical radiator
CAt a voltage node
DAs close to the transmitter as possible

47. - E9E08

What is a use for a Wilkinson divider?

SelectAnswer
AIt is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
BIt divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
CIt is used to feed low-impedance loads from a high-impedance source
DIt is used to feed high-impedance antennas from a low-impedance source

48. - E9F07

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

SelectAnswer
ALower loss
BSmaller reflection coefficient
CLower velocity factor
DHigher SWR

49. - E9G10

What do the arcs on a Smith chart represent?

SelectAnswer
AFrequency
BPoints with constant resistance
CPoints with constant reactance
DSWR

50. - E9H04

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

SelectAnswer
AIt adds capacitive loading, increasing the bandwidth of the antenna
BIt increases signal strength by providing a better match to the feed line
CIt eliminates tracking errors caused by strong out-of-band signals
DIt eliminates unbalanced capacitive coupling to the surroundings, improving the nulls