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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

SelectAnswer
APolychlorinated biphenyls
BPolymorphic silicon
CPolytetrafluoroethylene
DPolyethylene

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

SelectAnswer
A1 watt EIRP
B100 watts PEP
C50 watts PEP
D5 watts EIRP

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

SelectAnswer
AFile an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
BCease operation or make changes to the repeater to mitigate the interference
CReduce the repeater antenna HAAT (Height Above Average Terrain)
DAll these choices are correct

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

SelectAnswer
A23 dB
B26 dB
C6 dB
D3 dB

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

SelectAnswer
AAny amateur station so designated by the ITU
BAny amateur station designated by NASA
CAll these choices are correct
DAny amateur station so designated by the space station licensee

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

SelectAnswer
AThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
BPhotocopy all examination documents and forward them to the FCC for processing
CIssue the examinee the new or upgrade license
DAll these choices are correct

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

SelectAnswer
AOnly on amateur frequencies above 222 MHz
BOnly on amateur frequencies above 420 MHz
COnly on amateur frequencies above 144 MHz
DOnly on amateur frequencies above 50 MHz

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

SelectAnswer
AAll these choices are correct
BSSB and SSTV
CFM and CW
DPSK and packet

9. - E2B04

How is color information sent in analog SSTV?

SelectAnswer
AColor lines are sent sequentially
BColor is amplitude modulated on the frequency modulated intensity signal
CColor information is sent on a 2.8 kHz subcarrier
DColor is sent in a color burst at the end of each line

10. - E2C08

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

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

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

SelectAnswer
AAn APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
BAn APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
CAPRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
DAll these choices are correct

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?

SelectAnswer
AAnother station you are unable to hear is using the frequency
BYour transmit frequency is incorrect
CThe protocol version you are using is not supported by the digital station
DAll these choices are correct

13. - E3A01

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

SelectAnswer
A500 miles, if the moon is at perigee
B12,000 miles, if the moon is visible by both stations
C5000 miles, if the moon is at perigee
D2000 miles, if the moon is at apogee

14. - E3B12

What is the primary characteristic of chordal hop propagation?

SelectAnswer
APropagation across the geomagnetic equator
BPropagation away from the great circle bearing between stations
CSignals reflected back toward the transmitting station
DSuccessive ionospheric refractions without an intermediate reflection from the ground

15. - E3C11

What does VOACAP software model?

SelectAnswer
AAC current and impedance
BHF propagation
CAC voltage and impedance
DVHF radio propagation

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

SelectAnswer
AAll signals will have a DC offset
BCalibration of the vertical scale is no longer valid
CExcessive blanking occurs, which prevents display of the signal
DA false, jittery low-frequency version of the signal is displayed

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

SelectAnswer
AThe inductance to capacitance ratio
BThe bandwidth of the circuit's frequency response
CThe frequency shift
DThe resonant frequency of the circuit

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

SelectAnswer
A14.755 MHz
B14.445 MHz
C15.210 MHz
D13.845 MHz

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

SelectAnswer
AThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
BSignals less than 40 dBm will not generate audible third-order intermodulation products
CA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
DA pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals

20. - E4E03

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

SelectAnswer
ASignals that appear across a wide bandwidth
BSignals that are constant at all IF levels
CSignals that have a sharply peaked frequency distribution
DSignals that appear at one IF but not another

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

SelectAnswer
A315.6 Hz
B157.8 Hz
C47.3 kHz
D23.67 kHz

22. - E5B06

What is susceptance?

SelectAnswer
AThe magnetic impedance of a circuit
BA measure of the efficiency of a transformer
CThe ratio of magnetic field to electric field
DThe imaginary part of admittance

23. - E5C03

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

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

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

SelectAnswer
AIt is dissipated as heat in the circuit
BIt is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
CIt is dissipated as kinetic energy in the circuit
DIt is dissipated in the formation of inductive and capacitive fields

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAn FET that exhibits a current flow between source and drain when no gate voltage is applied
BAn FET that has no current flow between source and drain when no gate voltage is applied
CAny FET for which holes are the majority carriers
DAny FET without a channel

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

SelectAnswer
ALess forward voltage drop
BMore constant reverse avalanche voltage
CLonger carrier retention time
DMuch higher reverse voltage breakdown

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

SelectAnswer
A1
B2
C4
D3

28. - E6D09

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

SelectAnswer
AElectrolytic capacitors
BFerrite beads
CButterworth filters
DSteel-core toroids

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

SelectAnswer
ALow leakage doubly insulated package
BA total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
CPackage mounts in a direct inverted position
DTwo chips in each package (Dual In Package)

30. - E6F09

What is the efficiency of a photovoltaic cell?

SelectAnswer
AThe open-circuit voltage divided by the short-circuit current under full illumination
BThe relative fraction of light that is converted to current
CThe output RF power divided by the input DC power
DCost per kilowatt-hour generated

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

SelectAnswer
A8
B4
C2
D1

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

SelectAnswer
AA two-transistor amplifier with the emitters sharing a common bias resistor
BAn amplifier with a low impedance output that follows the base input voltage
CA differential amplifier with both inputs fed to the emitter of the input transistor
DAn OR circuit with only one emitter used for output

33. - E7C06

What are the distinguishing features of an elliptical filter?

SelectAnswer
AExtremely sharp cutoff with one or more notches in the stop band
BGradual passband rolloff with minimal stop band ripple
CExtremely flat response over its pass band with gradually rounded stop band corners
DGradual passband rolloff with extreme stop band ripple

34. - E7D03

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

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

35. - E7E07

What is meant by the term "baseband" in radio communications?

SelectAnswer
AThe frequency range occupied by a message signal prior to modulation
BThe unmodulated bandwidth of the transmitted signal
CThe basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
DThe lowest frequency band that the transmitter or receiver covers

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

SelectAnswer
A8 bits
B10 bits
C6 bits
D4 bits

37. - E7G03

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

SelectAnswer
A100 ohms
BVery low
C1000 ohms
DVery high

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

SelectAnswer
AA phase-locked loop synthesizer
BA hybrid synthesizer
CA diode-switching matrix synthesizer
DA direct digital synthesizer

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
BImmunity to out-of-sequence coding reduces spurious responses
CVery high speed allows digitizing high frequencies
DAll these choices are correct

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
AThe transmitted signal jumps from band to band at a predetermined rate
BTwo or more information streams are merged into a baseband, which then modulates the transmitter
CThe transmitted signal is divided into packets of information
DTwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

SelectAnswer
A15.36 kHz
B9.6 kHz
C4.8 kHz
D5.76 kHz

42. - E8D09

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

SelectAnswer
A-20 dB
B+10 dB
C+15 dB
D-30 dB

43. - E9A09

What is antenna efficiency?

SelectAnswer
ATotal resistance divided by radiation resistance
BRadiation resistance divided by total resistance
CEffective radiated power divided by transmitter output
DRadiation resistance divided by transmission resistance

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

SelectAnswer
A24 dB
B18 dB
C36 dB
D14 dB

45. - E9C09

Which of the following describes a G5RV antenna?

SelectAnswer
AA multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
BA multi-band trap antenna
CA phased array antenna consisting of multiple loops
DA wide band dipole using shorted coaxial cable for the radiating elements and fed with aÿ4:1 balun

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
AStranded wire
BResistive wire, such as spark plug wire
CSolid wire
DWide flat copper strap

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

SelectAnswer
AThe driven element reactance must be capacitive
BThe driven element radiation resistance must be higher than the characteristic impedance of the transmission line
CThe driven element reactance must be inductive
DThe driven element resonance must be lower than the operating frequency

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

SelectAnswer
A5.2 meters
B8.3 meters
C6.9 meters
D10.4 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

SelectAnswer
ADetermine the impedance of a transmission line, given the physical dimensions
BDetermine the length and position of an impedance matching stub
CDetermine the gain of an antenna given the physical and electrical parameters
DDetermine the loss/100 feet of a transmission line, given the velocity factor and conductor materials

50. - E9H06

What is the triangulation method of direction finding?

SelectAnswer
AA fixed receiving station plots three headings to the signal source
BAntenna headings from several different receiving locations are used to locate the signal source
CThe geometric angles of sky waves from the source are used to determine its position
DA fixed receiving station uses three different antennas to plot the location of the signal source

Figure E6-3

Figure E9-1