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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

SelectAnswer
AThe extremely high frequency energy can damage the joints of antenna structures
BThe high gain antennas commonly used can result in high exposure levels
CMicrowaves are ionizing radiation
DMicrowaves often travel long distances by ionospheric reflection

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

SelectAnswer
AThey are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
BThey are not permitted above 54 MHz
CThey are restricted to phone band segments
DNone; they are allowed on all amateur frequencies

3. - E1B09

Which amateur stations may be operated under RACES rules?

SelectAnswer
AAny FCC-licensed amateur station except a Technician Class
BAny FCC-licensed amateur station certified by the responsible civil defense organization for the area served
COnly those club stations licensed to Amateur Extra Class operators
DAny FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

SelectAnswer
ANone
BThe entire band
COnly the top 3 kHz
DOnly the bottom 3 kHz

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
AAll these choices are correct
BAny amateur station so designated by the space station licensee
CAny amateur station designated by NASA
DAny amateur station so designated by the ITU

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

SelectAnswer
AWarn the candidate that continued failure to comply will result in termination of the examination
BImmediately terminate the candidate's examination
CImmediately terminate everyone's examination and close the session
DAllow the candidate to complete the examination, but invalidate the results

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

SelectAnswer
AIt was imported from a manufacturer in another country and was certificated by that country's government
BThe equipment dealer assembled it from a kit
CIt was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
DIt was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A10

What type of satellite appears to stay in one position in the sky?

SelectAnswer
AHEO
BGeostationary
CGeomagnetic
DLEO

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

SelectAnswer
ATone frequency
BSync frequency
CSync amplitude
DTone amplitude

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

SelectAnswer
ANo additional indicator is required
B/ followed by the ARRL Section of the remote station
C/R# where # is the district of the remote station
D/ followed by the USPS two-letter abbreviation for the state in which the remote station is located

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

SelectAnswer
A15-second timed transmission sequences with stations alternating based on location
BShort transmissions with rapidly repeated call signs and signal reports
CUse of special digital modes
DAll these choices are correct

12. - E2E08

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

SelectAnswer
ARTTY
BAMTOR
CHellschreiber
DPACTOR

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

SelectAnswer
AUrban areas
BBodies of water
CMountain ranges
DForests

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

SelectAnswer
ALong-path and short-path waves
BIndependent waves created in the ionosphere that are elliptically polarized
CExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
DRefracted rays and reflected waves

15. - E3C07

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

SelectAnswer
AClass M
BClass B
CClass X
DClass A

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

SelectAnswer
ANever use a DC-coupled probe to measure an AC circuit
BKeep the signal ground connection of the probe as short as possible
CNever use a high-impedance probe to measure a low-impedance circuit
DAll these choices are correct

17. - E4B05

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

SelectAnswer
AShort circuit, open circuit, and resonant circuit
B50 ohms, 75 ohms, and 90 ohms
C50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
DShort circuit, open circuit, and 50 ohms

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

SelectAnswer
AA properly adjusted product detector
BA notch filter
CA front-end filter or pre-selector
DA narrow IF filter

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

SelectAnswer
AIncrease the receiver front end gain
BSwitch from fast AGC to slow AGC
CDecrease the RF bandwidth of the receiver
DRaise the receiver IF frequency

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

SelectAnswer
ANearby signals may appear to be excessively wide even if they meet emission standards
BReceived audio in the speech range might have an echo effect
CFM signals can no longer be demodulated
DThe audio frequency bandwidth of the received signal might be compressed

21. - E5A07

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

SelectAnswer
AMaximum
BR/L
CMinimum
DL/R

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

SelectAnswer
A14 degrees with the voltage leading the current
B14 degrees with the voltage lagging the current
C76 degrees with the voltage leading the current
D76 degrees with the voltage lagging the current

23. - E5C02

How are impedances described in polar coordinates?

SelectAnswer
ABy X and R values
BBy phase angle and magnitude
CBy real and imaginary parts
DBy Y and G values

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

SelectAnswer
A70.7 watts
B100 watts
C200 watts
D141.4 watts

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

SelectAnswer
ABeta cutoff frequency
BAlpha rejection frequency
CCorner frequency
DAlpha cutoff frequency

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

SelectAnswer
AReverse voltage larger than the RF signal
BA sub-harmonic pump signal
CCapacitance of an RF coupling capacitor
DForward DC bias current

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AAll these choices are correct
BIts simplicity results in much less expensive devices than standard CMOS
CIt has the high input impedance of CMOS and the low output impedance of bipolar transistors
DIt is immune to electrostatic damage

28. - E6D05

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

SelectAnswer
AFerrite toroids generally have lower initial permeability
BFerrite toroids are easier to use with surface mount technology
CFerrite toroids generally require fewer turns to produce a given inductance value
DFerrite toroids generally have better temperature stability

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

SelectAnswer
AEpoxy coating is conductive above 300 MHz
BUnsuitable for combining analog and digital signals
CToo many pins
DExcessive lead length

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A01

Which circuit is bistable?

SelectAnswer
AAn AND gate
BA flip-flop
CA bipolar amplifier
DAn OR gate

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

SelectAnswer
AHigh filament voltage
BLow bandwidth
CHigh power gain
DLow input impedance

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

SelectAnswer
APermits a wide range of output voltage settings
BProvides a stable input impedance over a wide range of source voltage
CMaintains nearly constant output voltage over a wide range of load current
DMaintains nearly constant output impedance over a wide range of load current

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

SelectAnswer
AThe two input frequencies along with their sum and difference frequencies
B1.414 and 0.707 times the input frequency
CThe square root of the product of input frequencies
DTwo and four times the original frequency

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

SelectAnswer
AMixing products are converted to voltages and subtracted by adder circuits
BA frequency synthesizer removes the unwanted sidebands
CVarying quartz crystal characteristics emulated in digital form
DSignals are combined in quadrature phase relationship

37. - E7G03

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

SelectAnswer
AVery high
BVery low
C1000 ohms
D100 ohms

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

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?

SelectAnswer
AFourier analysis
BDifferential analysis
CVector analysis
DNumerical analysis

40. - E8B01

What is the modulation index of an FM signal?

SelectAnswer
AThe ratio of modulating signal amplitude to frequency deviation
BThe bandwidth of the transmitted signal divided by the modulating signal frequency
CThe type of modulation used by the transmitter
DThe ratio of frequency deviation to modulating signal frequency

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

SelectAnswer
A0.3 kHz
B0.1 Hz
C1.0 kHz
D0.5 kHz

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

SelectAnswer
AFrequency hopping
BBinary phase-shift keying
CDirect sequence
DPhase compandored spread spectrum

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

SelectAnswer
A252 watts
B63.2 watts
C159 watts
D632 watts

44. - E9B05

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

SelectAnswer
ARadiation resistance
BAzimuth
CPolarization
DElevation

45. - E9C08

What is a folded dipole antenna?

SelectAnswer
AA dipole configured to provide forward gain
BA type of ground-plane antenna
CA half-wave dipole with an additional parallel wire connecting its two ends
DA dipole one-quarter wavelength long

46. - E9D05

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

SelectAnswer
AThe SWR is reduced
BThe front-to-back ratio increases
CThe front-to-back ratio decreases
DThe frequency response is widened over the whole frequency band

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

SelectAnswer
AGamma match
BAll these choices are correct
CHairpin match
DDouble-bazooka match

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
AAn inductive reactance
BZero
CThe same as the characteristic impedance of the line
DA capacitive reactance

49. - E9G02

What type of coordinate system is used in a Smith chart?

SelectAnswer
AVoltage lines and current chords
BResistance circles and reactance arcs
CVoltage circles and current arcs
DResistance lines and reactance chords

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

SelectAnswer
AIt is practical for use only on VHF and higher bands
BIt has no clearly defined null
CAll these choices are correct
DIt has a bidirectional pattern

Figure E9-2