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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
A300 to 3000 MHz
B3 to 30 MHz
C30 to 300 MHz
D300 kHz to 3 MHz

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

SelectAnswer
A14.149 MHz
B14.100 MHz
C14.349 MHz
D14.070 MHz

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

SelectAnswer
A20 kHz
B10 kHz
C15 kHz
D3 kHz

4. - E1C04

What is meant by IARP?

SelectAnswer
AA forecast of intermittent aurora radio propagation
BAn indication of increased antenna reflected power
CThe internal amateur radio practices policy of the FCC
DAn international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas

5. - E1D03

What is a space telecommand station?

SelectAnswer
AAn amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
BAn amateur station that transmits communications to initiate, modify or terminate functions of a space station
CAn amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
DAn amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites

6. - E1E09

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

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

7. - E1F06

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

SelectAnswer
ATo provide additional spectrum for personal use
BTo provide for experimental amateur communications
CTo provide temporary operation while awaiting normal licensing
DTo allow regular operation on Land Mobile channels

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

SelectAnswer
AUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa
BAll these choices are correct
CSignal position in the band is reversed
DDoppler shift is reduced because the uplink and downlink shifts are in opposite directions

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

SelectAnswer
ABy scanning odd numbered lines in one field and even numbered lines in the next
BBy scanning lines from left to right in one field and right to left in the next
CBy scanning each field from bottom to top
DBy scanning two fields simultaneously

10. - E2C04

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

SelectAnswer
AFrequencies shared with various unlicensed wireless data services
BHF frequencies where digital communications are permitted
CThe 60 meter band channel centered on 5373 kHz
DCable TV channels 41 through 43

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

SelectAnswer
AAPRS
BDoppler shift of beacon signals
CBandwidth compressed LORAN
DUltrasonics

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

SelectAnswer
AMFSK
BPSK31
CRTTY
DPACTOR

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

SelectAnswer
AThe jet stream
BDust devil
CWind shear
DTemperature inversion

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
A6 meters to 2 meters
BOnly 30 meters to 10 meters
COnly 160 meters to 40 meters
D160 meters to 10 meters

15. - E3C08

What does the space weather term G5 mean?

SelectAnswer
AAn extreme geomagnetic storm
BWaning sunspot numbers
CVery low solar activity
DModerate solar wind

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

SelectAnswer
AA square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
BA frequency standard is displayed and the probe is adjusted until the deflection time is accurate
CA high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
DA DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
AFrequency order of the measurements
BRelative quality of the data
CThe port or ports at which measurements are made
DThe relative time between measurements

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

SelectAnswer
AThe attenuator has a low-pass filter to increase the strength of lower frequency signals
BThe attenuator has a noise filter to suppress interference
CSignals are attenuated separately from the noise
DAtmospheric noise is generally greater than internally generated noise even after attenuation

19. - E4D08

What causes intermodulation in an electronic circuit?

SelectAnswer
AToo little gain
BNonlinear circuits or devices
CPositive feedback
DLack of neutralization

20. - E4E08

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

SelectAnswer
ADifferential-mode current
BCommon-mode current
CReactive current only
DReturn current

21. - E5A06

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

SelectAnswer
AIt is at a maximum
BIt equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
CIt equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
DIt is at a minimum

22. - E5B09

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

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

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 7
BPoint 8
CPoint 3
DPoint 1

24. - E5D01

What is the result of skin effect?

SelectAnswer
AThermal effects on the surface of the conductor increase the impedance
BAs frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
CAs frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
DThermal effects on the surface of the conductor decrease the impedance

25. - E6A09

What is a depletion-mode FET?

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

26. - E6B10

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

SelectAnswer
A5
B1
C6
D7

27. - E6C03

What is tri-state logic?

SelectAnswer
ALogic devices that utilize ternary math
BLogic devices with 0, 1, and high-impedance output states
CLow-power logic devices designed to operate at 3 volts
DProprietary logic devices manufactured by Tri-State Devices

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
APermeability
BReactivity
CResistance
DThermal impedance

29. - E6E11

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

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

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A01

Which circuit is bistable?

SelectAnswer
AAn OR gate
BAn AND gate
CA bipolar amplifier
DA flip-flop

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

SelectAnswer
ACreation of parasitic oscillations
BLow efficiency
CTransmission of spurious signals
DAll these choices are correct

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

SelectAnswer
AA DSP filter
BA cavity filter
CA crystal filter
DAn L-C filter

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

SelectAnswer
AInput voltage multiplied by input current
BOutput voltage multiplied by output current
CVoltage difference from input to output multiplied by output current
DInput voltage divided by output current

35. - E7E05

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

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

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

SelectAnswer
AA notch filter
BA Hilbert-transform filter
CAn elliptical filter
DAn adaptive filter

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

SelectAnswer
A0.03
B1
C76
D38

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

SelectAnswer
AWirewound resistors
BToroidal inductors
CNon-inductive resistors
DNP0 capacitors

39. - E8A05

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

SelectAnswer
AA grid dip meter
BA D'Arsonval meter
CA true-RMS calculating meter
DAn absorption wave meter

40. - E8B01

What is the modulation index of an FM signal?

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

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
ABaud is twice the symbol rate
BBaud is only used for RTTY
CSymbol rate is only used for packet-based modes
DThey are the same

42. - E8D05

What is the most common method of reducing key clicks?

SelectAnswer
AHigh-pass filters at the transmitter output
BLow-pass filters at the transmitter output
CIncrease keying waveform rise and fall times
DReduce keying waveform rise and fall times

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
B420 watts
C1977 watts
D78.7 watts

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

SelectAnswer
AMutual impedance analysis
BCalculus differentiation with respect to physical properties
CGraphical analysis
DMethod of Moments

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 multiband dipole antenna using one-way circular polarization for frequency diversity
DA remotely tunable dipole antenna using orthogonally controlled frequency diversity

46. - E9D08

What happens as the Q of an antenna increases?

SelectAnswer
ASWR bandwidth increases
BSWR bandwidth decreases
CGain is reduced
DMore common-mode current is present on the feed line

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

SelectAnswer
ATo cancel the inductive reactance of the matching network
BTo provide DC isolation between the feed line and the antenna
CTo transform the antenna impedance to a higher value
DTo provide a rejection notch that prevents the radiation of harmonics

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

SelectAnswer
AThe characteristic impedance is higher in a parallel feed line
BSkin effect is less pronounced in the coaxial cable
CElectrical signals move more slowly in a coaxial cable than in air
DThe surge impedance is higher in a parallel feed line

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

SelectAnswer
AVoltage and impedance
BResistance and reactance
CReactance and voltage
DResistance and voltage

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

SelectAnswer
ALow loss coax transmission line is essential for good performance
BAll these choices are correct
CThey must be erected at least 1/2 wavelength above the ground to attain good directivity
DAtmospheric noise is so high that gain over a dipole is not important

Figure E5-1

Figure E6-2

Figure E7-3