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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. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

SelectAnswer
ADiscontinue forwarding the communication as soon as you become aware of it
BNotify the originating station that the communication does not comply with FCC rules
CNotify the nearest FCC Field Engineers office
DAll these choices are correct

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

SelectAnswer
A10 miles
B30 miles
C1 mile
D3 miles

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

SelectAnswer
AAll these choices are correct
BIARP agreement
CCEPT agreement
DITU reciprocal license

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. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

SelectAnswer
AThe amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
BThe procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
CThe prospective VE obtains accreditation from the FCC
DEach General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

7. - E1F06

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

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

8. - E2A02

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

SelectAnswer
ADoppler shift is reduced because the uplink and downlink shifts are in opposite directions
BSignal position in the band is reversed
CAll these choices are correct
DUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa

9. - E2B10

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

SelectAnswer
ATone frequency
BSync amplitude
CTone amplitude
DSync frequency

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

SelectAnswer
AThe often-prohibited practice of posting one's own call sign and frequency on a spotting network
BThe acceptable practice of manually posting the call signs of stations on a spotting network
CA manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
DAn automatic method for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

SelectAnswer
AUnnumbered Information
BDisconnect
CConnect
DAcknowledgement

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

SelectAnswer
AAMTOR
B170 Hz shift, 45 baud RTTY
C300 baud packet
DPSK31

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

SelectAnswer
AWait 90 minutes or so for the signal degradation to pass
BSwitch to a higher frequency HF band
CSwitch to a lower frequency HF band
DWait 24 hours before attempting another communication on the band

14. - E3B01

What is transequatorial propagation?

SelectAnswer
APropagation between a point on the equator and its antipodal point
BPropagation between points located on the magnetic equator
CPropagation between points at the same latitude
DPropagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

SelectAnswer
AFour times as great
B50 percent greater
CTwice as great
D10 percent greater

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

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

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

SelectAnswer
AThere is possibly a short to ground in the feed line
BThe transmitter is not properly neutralized
CThere is more power going into the antenna
DThere is an impedance mismatch between the antenna and feed line

18. - E4C15

What is reciprocal mixing?

SelectAnswer
AIn-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
BLocal oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
CTwo out-of-band signals mixing to generate an in-band spurious signal
DTwo digital signals combining from alternate time slots

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

SelectAnswer
ADesensitization
BCross-modulation interference
CSquelch gain rollback
DQuieting

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

SelectAnswer
APower line noise
BAll these choices are correct
CIgnition noise
DBroadband white noise

21. - E5A15

Which of the following increases Q for inductors and capacitors?

SelectAnswer
ALower losses
BLower self-resonant frequency
CLower reactance
DHigher self-resonant frequency

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

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

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

SelectAnswer
AOn a line through the origin, slanted at 45 degrees
BOn the horizontal axis
COn a horizontal line, offset vertically above the horizontal axis
DOn the vertical axis

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

SelectAnswer
A80 watts
B50 watts
C2000 watts
D400 watts

25. - E6A06

What is the beta of a bipolar junction transistor?

SelectAnswer
AThe breakdown voltage of the base to collector junction
BThe switching speed
CThe frequency at which the current gain is reduced to 0.707
DThe change in collector current with respect to base current

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

SelectAnswer
AVaractor diode
BSilicon-controlled rectifier
CZener diode
DTunnel diode

27. - E6C08

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

SelectAnswer
A2
B4
C3
D1

28. - E6D04

Which materials are commonly used as a core in an inductor?

SelectAnswer
AFerrite and brass
BCobalt and aluminum
CTeflon and Delrin
DPolystyrene and polyethylene

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

SelectAnswer
A10 ohms
B300 ohms
C450 ohms
D50 ohms

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

SelectAnswer
AA frequency modulated helium-neon laser
BA lens and a photomultiplier
CAn amplitude modulated helium-neon laser
DAn LED and a phototransistor

31. - E7A07

What logical operation does a NAND gate perform?

SelectAnswer
AIt produces logic 0 at its output only when all inputs are logic 0
BIt produces logic 1 at its output only when all inputs are logic 1
CIt produces logic 0 at its output if some but not all inputs are logic 1
DIt produces logic 0 at its output only when all inputs are logic 1

32. - E7B05

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

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

33. - E7C06

What are the distinguishing features of an elliptical filter?

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

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

SelectAnswer
AThe inverter design does not require any output filtering
BIt uses a diode bridge rectifier for increased output
CIt uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
DThe high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

35. - E7E02

What is the function of a reactance modulator?

SelectAnswer
ATo produce PM or FM signals by using an electrically variable inductance or capacitance
BTo produce AM signals by using an electrically variable inductance or capacitance
CTo produce AM signals by using an electrically variable resistance
DTo produce PM signals by using an electrically variable resistance

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

SelectAnswer
AIt peaks the response of the decimator, improving bandwidth
BIt notches out the sampling frequency to avoid sampling errors
CIt removes high-frequency signal components that would otherwise be reproduced as lower frequency components
DIt removes low-frequency signal components to eliminate the need for DC restoration

37. - E7G03

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

SelectAnswer
AVery low
B1000 ohms
C100 ohms
DVery high

38. - E7H07

How can an oscillator's microphonic responses be reduced?

SelectAnswer
AMechanically isolate the oscillator circuitry from its enclosure
BUse NP0 capacitors
CReduce noise on the oscillator's power supply
DIncrease the bias voltage

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

SelectAnswer
AAmplifier gain
BThe frequency of the modulating signal
CThe degree of carrier suppression
DSpeech characteristics

40. - E8B01

What is the modulation index of an FM signal?

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

41. - E8C06

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

SelectAnswer
A0.5 kHz
B1.0 kHz
C0.1 Hz
D0.3 kHz

42. - E8D08

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

SelectAnswer
ABaud rate
BRepeat Request Rate (RRR)
CSignal-to-noise ratio
DIntermodulation Distortion (IMD)

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

SelectAnswer
ATake-off angle
BThe standing wave ratio
CSoil conductivity
DDistance from the transmitter

44. - E9B06

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

SelectAnswer
A45 degrees
B7.5 degrees
C75 degrees
D25 degrees

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

SelectAnswer
AA figure-8 broadside to the axis of the array
BOmni-directional
CCardioid
DA figure-8 oriented along the axis of the array

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

SelectAnswer
ATo minimize losses
BTo minimize the Q
CTo swamp out harmonics
DTo lower the radiation angle

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

SelectAnswer
AThe delta match
BThe stub match
CThe gamma match
DThe omega match

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AVery high impedance
BThe same as the characteristic impedance of the transmission line
CVery low impedance
DThe same as the generator output impedance

49. - E9G10

What do the arcs on a Smith chart represent?

SelectAnswer
AFrequency
BPoints with constant resistance
CPoints with constant reactance
DSWR

50. - E9H09

What is a Pennant antenna?

SelectAnswer
AA stealth antenna built to look like a flagpole
BA form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
CA four-element, high-gain vertical array invented by George Pennant
DA small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms

Figure E6-3

Figure E9-2