Anonymous User

Hamboozler

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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A08

What does SAR measure?

SelectAnswer
ASynthetic Aperture Ratio of the human body
BThe rate at which RF energy is absorbed by the body
CThe rate of RF energy reflected from stationary terrain
DSignal Amplification Rating

2. - E1A09

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

SelectAnswer
ANotify the originating station that the communication does not comply with FCC rules
BAll these choices are correct
CDiscontinue forwarding the communication as soon as you become aware of it
DNotify the nearest FCC Field Engineers office

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

SelectAnswer
AYou may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
BYou must file an Environmental Impact Statement with the EPA before construction begins
CYou must obtain a construction permit from the airport zoning authority
DYou must submit engineering drawings to the FAA

4. - E1C06

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

SelectAnswer
AYou must bring a copy of FCC Public Notice DA 16-1048
BYou must identify in the official language of the country in which you are operating
CYou must append "/CEPT" to your call sign
DThe U.S. embassy must approve of your operation

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

SelectAnswer
A100 watts
B1 watt
C5 watts
D2 watts

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

SelectAnswer
AThey must collect and submit the documents to the coordinating VEC for grading
BThey must submit the application document to the coordinating VEC according to the coordinating VEC instructions
CThey must collect and send the documents to the FCC according to instructions
DThey must collect and send the documents to the NCVEC for grading

7. - E1F08

Which of the following types of amateur station communications are prohibited?

SelectAnswer
ACommunications that have religious content
BCommunications transmitted for hire or material compensation, except as otherwise provided in the rules
CCommunications that have political content, except as allowed by the Fairness Doctrine
DCommunications in a language other than English

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

SelectAnswer
ATo upload operational software for the transponder
BTo store digital messages in the satellite for later download by other stations
CTo relay messages between satellites
DTo delay download of telemetry between satellites

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 identify the call sign of the station transmitting
CTo provide vertical synchronization
DTo identify the SSTV mode being used

10. - E2C02

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

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

11. - E2D02

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

SelectAnswer
AShort transmissions with rapidly repeated call signs and signal reports
BAll these choices are correct
C15-second timed transmission sequences with stations alternating based on location
DUse of special digital modes

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

SelectAnswer
ARTTY
BPACTOR
CMT63
DPSK31

13. - E3A04

What do Hepburn maps predict?

SelectAnswer
ASporadic E propagation
BLikelihood of rain scatter along cold or warm fronts
CProbability of tropospheric propagation
DLocations of auroral reflecting zones

14. - E3B10

Why is chordal hop propagation desirable?

SelectAnswer
AAtmospheric noise is lower in the direction of chordal hop propagation
BSignals travel faster along ionospheric chords
CThe MUF for chordal hop propagation is much lower than for normal skip propagation
DThe signal experiences less loss compared to multi-hop using Earth as a reflector

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

SelectAnswer
ASouthward
BNorthward
CEastward
DWestward

16. - E4A09

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

SelectAnswer
AS12
BS22
CS11
DS21

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

SelectAnswer
AIt limits the receiver's ability to receive strong signals
BIt decreases receiver third-order intercept point
CIt can combine with strong signals on nearby frequencies to generate interference
DIt can affect the receiver's frequency calibration

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

SelectAnswer
AAmplifier desensitization
BNeutralization
CAdjacent channel interference
DIntermodulation

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

SelectAnswer
ANearby corroded metal joints are mixing and re-radiating the broadcast signals
BOne or more of the broadcast stations is transmitting an over-modulated signal
CYou are receiving skywave signals from a distant station
DYour station receiver IF amplifier stage is defective

21. - E5A07

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

SelectAnswer
AL/R
BMaximum
CMinimum
DR/L

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

SelectAnswer
A440 seconds
B220 seconds
C55 seconds
D110 seconds

23. - E5C06

What does the impedance 50-j25 represent?

SelectAnswer
A50 ohms resistance in series with 25 ohms capacitive reactance
B25 ohms resistance in series with 50 ohms inductive reactance
C25 ohms resistance in series with 50 ohms capacitive reactance
D50 ohms resistance in series with 25 ohms inductive reactance

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. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

SelectAnswer
ABase-to-emitter resistance of approximately 6 to 7 ohms
BBase-to-emitter voltage of approximately 0.6 to 0.7 volts
CBase-to-emitter voltage of approximately 6 to 7 volts
DBase-to-emitter resistance of approximately 0.6 to 0.7 ohms

26. - E6B01

What is the most useful characteristic of a Zener diode?

SelectAnswer
AA constant current drop under conditions of varying voltage
BA negative resistance region
CA constant voltage drop under conditions of varying current
DAn internal capacitance that varies with the applied voltage

27. - E6C03

What is tri-state logic?

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

28. - E6D04

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

SelectAnswer
APolystyrene and polyethylene
BCobalt and aluminum
CFerrite and brass
DTeflon and Delrin

29. - E6E02

Which of the following device packages is a through-hole type?

SelectAnswer
ABall grid array
BDIP
CSOT
DPLCC

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

SelectAnswer
ASilicon
BCadmium Sulfide
CSelenium
DCopper oxide

31. - E7A01

Which circuit is bistable?

SelectAnswer
AA flip-flop
BAn AND gate
CAn OR gate
DA bipolar amplifier

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

SelectAnswer
AEmitter follower
BCommon collector
CCommon base
DCommon emitter

33. - E7C09

What is a crystal lattice filter?

SelectAnswer
AAn audio filter made with four quartz crystals that resonate at 1 kHz intervals
BA filter using lattice-shaped quartz crystals for high-Q performance
CA filter with narrow bandwidth and steep skirts made using quartz crystals
DA power supply filter made with interlaced quartz crystals

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

SelectAnswer
AThe resistance of a control element is varied in direct proportion to the line voltage or load current
BIt is generally less efficient than a linear regulator
CIt gives a ramp voltage at its output
DThe controlled device's duty cycle is changed to produce a constant average output voltage

35. - E7E01

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

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

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

SelectAnswer
AAt four times the rate of the highest frequency component of the signal
BAt the same rate as the highest frequency component of the signal
CAt least twice the rate of the highest frequency component of the signal
DAt least half the rate of the highest frequency component of the signal

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

SelectAnswer
A-0.23 volts
B2.3 volts
C-2.3 volts
D0.23 volts

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

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

SelectAnswer
AA sawtooth wave
BA cosine wave
CA sine wave
DA square wave

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

SelectAnswer
AIt does not depend on the RF carrier frequency
BIt decreases as the RF carrier frequency increases
CIt increases as the RF carrier frequency increases
DIt varies with the square root of the RF carrier frequency

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
ASymbol rate is only used for packet-based modes
BBaud is twice the symbol rate
CThey are the same
DBaud is only used for RTTY

42. - E8D02

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

SelectAnswer
ADirect sequence
BBinary phase-shift keying
CPhase compandored spread spectrum
DFrequency hopping

43. - E9A05

What is included in the total resistance of an antenna system?

SelectAnswer
ARadiation resistance plus loss resistance
BRadiation resistance plus transmission resistance
CTransmission-line resistance plus radiation resistance
DRadiation resistance plus space impedance

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

SelectAnswer
A50 degrees
B30 degrees
C75 degrees
D25 degrees

45. - E9C05

Which of the following is a type of OCFD antenna?

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

SelectAnswer
AIt is unchanged if the loading coil is located at the feed point
BIt is increased
CIt is unchanged if the loading coil is located at a voltage maximum point
DIt is decreased

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

SelectAnswer
AInsert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
BConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
CInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
DConnect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna

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 generator output impedance
CVery low impedance
DThe same as the characteristic impedance of the transmission line

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

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
BThey must be erected at least 1/2 wavelength above the ground to attain good directivity
CAll these choices are correct
DAtmospheric noise is so high that gain over a dipole is not important

Figure E7-1

Figure E7-3

Figure E9-1