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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A3 to 30 MHz
B300 to 3000 MHz
C300 kHz to 3 MHz
D30 to 300 MHz

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

SelectAnswer
A1 kHz above the lower band edge
B3 kHz above the lower band edge
CThe exact lower band edge
D300 Hz above the lower band edge

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AFAA tower height limits
BHomeowners associations
CUse of wireless devices in vehicles
DState and local zoning

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

SelectAnswer
AOperators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
BA special endorsement must be requested from the FCC
CAn environmental impact statement must be filed with the Department of the Interior
DOperators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

SelectAnswer
AAll these choices are correct
BA photocopy of the station license
CA label with the name, address, and telephone number of the control operator
DA label with the name, address, and telephone number of the station licensee

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

SelectAnswer
AAll these choices are correct
BRevocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
CA fine of up to $1000 per occurrence
DA sentence of up to one year in prison

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

SelectAnswer
AThe operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
BNone, they must obtain a U.S. license
CAll privileges of the Amateur Extra Class license
DFull privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands

8. - E2A08

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

SelectAnswer
ATo avoid reducing the downlink power to all other users
BTo avoid interfering with terrestrial QSOs
CTo prevent creating errors in the satellite telemetry
DTo prevent the satellite from emitting out-of-band signals

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

SelectAnswer
ATo lock the color burst oscillator in color SSTV images
BTo provide vertical synchronization
CTo identify the call sign of the station transmitting
DTo identify the SSTV mode being used

10. - E2C07

What is the Cabrillo format?

SelectAnswer
AA standard for submission of electronic contest logs
BThe most common set of contest rules
CThe rules of order for meetings between contest sponsors
DA method of exchanging information during a contest QSO

11. - E2D06

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

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

12. - E2E08

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

SelectAnswer
APACTOR
BRTTY
CHellschreiber
DAMTOR

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

SelectAnswer
AWhen the moon is full
BWhen the MUF is above 30 MHz
CWhen the moon is at apogee
DWhen the moon is at perigee

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

SelectAnswer
AAround the equinoxes, especially the fall equinox
BAround the solstices, especially the winter solstice
CAround the equinoxes, especially the spring equinox
DAround the solstices, especially the summer solstice

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

SelectAnswer
AClass A
BClass X
CClass B
DClass M

16. - E4A07

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

SelectAnswer
AAntenna analyzers automatically tune your antenna for resonance
BAll these choices are correct
CAntenna analyzers do not need an external RF source
DAntenna analyzers display a time-varying representation of the modulation envelope

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

SelectAnswer
AShort circuit, open circuit, and 50 ohms
B50 ohms, 75 ohms, and 90 ohms
CShort circuit, open circuit, and resonant circuit
D50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable

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?

SelectAnswer
AReduced drift
BImproved receiver noise figure
CFewer components in the receiver
DEasier for front-end circuitry to eliminate image responses

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
CA band-pass filter in the feed line between the transmitter and receiver
DUtilizing a Class D final amplifier

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

SelectAnswer
ADifferential-mode current
BReturn current
CReactive current only
DCommon-mode current

21. - E5A03

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

SelectAnswer
AApproximately equal to capacitive reactance
BApproximately equal to inductive reactance
CHigh, as compared to the circuit resistance
DApproximately equal to circuit resistance

22. - E5B09

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

SelectAnswer
AVoltage leads current by 90 degrees
BVoltage and current are 180 degrees out of phase
CVoltage and current are in phase
DCurrent leads voltage by 90 degrees

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

SelectAnswer
APoint 8
BPoint 1
CPoint 7
DPoint 3

24. - E5D14

What is reactive power?

SelectAnswer
AWattless, nonproductive power
BPower consumed in circuit Q
CPower consumed in wire resistance in an inductor
DPower lost because of capacitor leakage

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

SelectAnswer
AIn very low-frequency RF circuits
BIn microwave circuits
CIn high-current rectifier circuits
DIn high-power audio circuits

26. - E6B09

What is a common use for point-contact diodes?

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

27. - E6C01

What is the function of hysteresis in a comparator?

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

28. - E6D08

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

SelectAnswer
APowdered-iron cores use smaller diameter wire for the same inductance
BPowdered-iron cores generally maintain their characteristics at higher currents
CPowdered-iron cores generally have greater initial permeability
DPowdered-iron cores generally require fewer turns to produce a given inductance

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

SelectAnswer
APlate current that is controlled by a control grid
BThe ability to retrieve information from a single signal even in the presence of other strong signals
CControlled gain, low noise figure, and constant input and output impedance over the specified frequency range
DNearly infinite gain, very high input impedance, and very low output impedance

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt becomes unstable
BIt stays the same
CIt increases
DIt decreases

31. - E7A03

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

SelectAnswer
AA flip-flop
BAn OR gate
CAn XOR gate
DA multiplexer

32. - E7B05

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

SelectAnswer
AUse a phase inverter in the output filter
BTune the stage for maximum SWR
CTune both the input and output for maximum power
DInstall parasitic suppressors and/or neutralize the stage

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

SelectAnswer
AA Phase Inverter Load network
BA Pi-network with an additional series inductor on the output
CA network with only three discrete parts
DA matching network in which all components are isolated from ground

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

SelectAnswer
AA Zener diode
BAn SCR
CA varactor diode
DA tunnel diode

35. - E7E01

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

SelectAnswer
AA balanced modulator on the audio amplifier
BA balanced modulator on the oscillator
CA reactance modulator on the final amplifier
DA reactance modulator on the oscillator

36. - E7F01

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

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

37. - E7G04

What is meant by the "op-amp input offset voltage"?

SelectAnswer
AThe differential input voltage needed to bring the open loop output voltage to zero
BThe output voltage of the op-amp minus its input voltage
CThe potential between the amplifier input terminals of the op-amp in an open loop condition
DThe difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

SelectAnswer
AProvide the crystal with a specified parallel capacitance
BBias the crystal at a specified voltage
CProvide the crystal with a specified parallel inductance
DBias the crystal at a specified current

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

SelectAnswer
AVery low power consumption decreases frequency drift
BAll these choices are correct
CVery high speed allows digitizing high frequencies
DImmunity to out-of-sequence coding reduces spurious responses

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

SelectAnswer
AA bandwidth compression technique using Fourier transforms
BA digital mode for narrow-band, slow-speed transmissions
CA frequency modulation technique that uses non-harmonically related frequencies
DA digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

41. - E8C05

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

SelectAnswer
A13 Hz
B104 Hz
C52 Hz
D26 Hz

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

SelectAnswer
AIntermodulation Distortion (IMD)
BRepeat Request Rate (RRR)
CSignal-to-noise ratio
DBaud rate

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

SelectAnswer
A286 watts
B78.7 watts
C1977 watts
D420 watts

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

SelectAnswer
A75 degrees
B7.5 degrees
C25 degrees
D45 degrees

45. - E9C05

Which of the following is a type of OCFD antenna?

SelectAnswer
AA dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
BA folded dipole center-fed with 300-ohm transmission line
CA remotely tunable dipole antenna using orthogonally controlled frequency diversity
DA multiband dipole antenna using one-way circular polarization for frequency diversity

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

SelectAnswer
AStack two Yagis fed in phase to form an array with the respective elements in parallel planes
BStack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
CArrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
DArrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

47. - E9E08

What is a use for a Wilkinson divider?

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

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AA capacitive reactance
BThe same as the characteristic impedance of the line
CZero
DAn inductive reactance

49. - E9G01

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

SelectAnswer
AAntenna radiation pattern
BRadio propagation
CImpedance along transmission lines
DRadiation resistance

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

SelectAnswer
ABy reducing the permeability of the loop shield
BBy increasing the number of turns and/or the area
CBy utilizing high impedance wire for the coupling loop
DBy winding adjacent turns in opposing directions

Figure E5-1

Figure E9-2