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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

SelectAnswer
ABeryllium Oxide
BZinc oxide
CUranium Hexafluoride
DMica

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

SelectAnswer
AAt the highest frequency of the channel
BOn any frequency where the signal's sidebands are within the channel
CAt the lowest frequency of the channel
DAt the center frequency of the channel

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

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

SelectAnswer
AOperations may commence immediately, and may continue unless interference is reported by the UTC
BOperators may not operate until a test signal has been transmitted in coordination with the local power company
COperators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
DOperators must not operate until approval is received

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

SelectAnswer
AOnly those of Amateur Extra Class operators
BAny amateur station, subject to the privileges of the class of operator license held by the control operator
CAny amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
DOnly those of General, Advanced or Amateur Extra Class operators

6. - E1E04

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

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

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

8. - E2A10

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

SelectAnswer
ALEO
BGeostationary
CHEO
DGeomagnetic

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
AAmplitude modulation in which one complete sideband and a portion of the other are transmitted
BSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
CA type of modulation in which one sideband is inverted
DNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

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
BSpecial event contacts between stations in the U.S.
CContacts using tactical call signs
DRepeater contacts between U.S. club members

11. - E2D06

Which of the following describes a method of establishing EME contacts?

SelectAnswer
AHigh-speed CW identification to avoid fading
BStoring and forwarding digital messages
CJudging optimum transmission times by monitoring beacons reflected from the moon
DTime synchronous transmissions alternately from each station

12. - E2E06

What is the most common data rate used for HF packet?

SelectAnswer
A300 baud
B1200 baud
C110 baud
D48 baud

13. - E3A14

What is meant by circularly polarized electromagnetic waves?

SelectAnswer
AWaves produced by a loop antenna
BWaves that circle the Earth
CWaves with a rotating electric field
DWaves with an electric field bent into a circular shape

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

SelectAnswer
A5000 miles
B7500 miles
C2500 miles
D1000 miles

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

SelectAnswer
AA temperature inversion has occurred
BIncreased transequatorial propagation is likely
CA solar flare has occurred
DLong-path propagation is likely

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

SelectAnswer
ASWR and frequency
BRF amplitude and time
CSWR and time
DRF amplitude and frequency

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

SelectAnswer
AModulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
BModulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
CModulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
DModulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

SelectAnswer
A-174 dBm
B-164 dBm
C-148 dBm
D-155 dBm

19. - E4D03

How can intermodulation interference between two repeaters occur?

SelectAnswer
AWhen the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
BWhen the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
CWhen the signals from the transmitters are reflected in phase from airplanes passing overhead
DWhen the signals from the transmitters are reflected out of phase from airplanes passing overhead

20. - E4E02

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

SelectAnswer
ABroadband white noise
BAll these choices are correct
CPower line noise
DIgnition noise

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

SelectAnswer
AParasitic effects are minimized
BPhase shift can become uncontrolled
CInternal voltages increase
DFewer components are needed for the same performance

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

SelectAnswer
AIt is shifted by 90 degrees
BIt becomes the reciprocal
CIt is unchanged
DThe sign is reversed

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 1
BPoint 7
CPoint 3
DPoint 8

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

SelectAnswer
ABy multiplying the apparent power by the power factor
BBy dividing the apparent power by the power factor
CBy dividing the reactive power by the power factor
DBy multiplying the reactive power by the power factor

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
AN-type
BInsulated gate
CP-type
DBipolar

26. - E6B09

What is a common use for point-contact diodes?

SelectAnswer
AAs an RF detector
BAs a constant current source
CAs a high-voltage rectifier
DAs a constant voltage source

27. - E6C03

What is tri-state logic?

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

28. - E6D05

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

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

29. - E6E12

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

SelectAnswer
AExcessive lead length
BEpoxy coating is conductive above 300 MHz
CToo many pins
DUnsuitable for combining analog and digital signals

30. - E6F10

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

SelectAnswer
ACadmium Sulfide
BSilicon
CCopper oxide
DSelenium

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
AAssertive Logic
BPositive Logic
CReverse Logic
DNegative logic

32. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

SelectAnswer
AThe tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
BThe loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
CThe tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
DThe loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

SelectAnswer
AIt cancels the reactive part of the impedance and changes the resistive part to a desired value
BIt introduces negative resistance to cancel the resistive part of impedance
CIt introduces transconductance to cancel the reactive part of impedance
DReactive currents are dissipated in matched resistances

34. - E7D08

What type of circuit is shown in Figure E7-2?

SelectAnswer
AMonostable multivibrator
BSwitching voltage regulator
CLinear voltage regulator
DGrounded emitter amplifier

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 audio amplifier
DA balanced modulator on the oscillator

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

SelectAnswer
AA Hilbert-transform filter
BA phase-inverting filter
CAn adaptive filter
DA crystal-lattice filter

37. - E7G03

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

SelectAnswer
AVery high
B1000 ohms
CVery low
D100 ohms

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

SelectAnswer
AUse a GPS signal reference
BAll these choices are correct
CUse a rubidium stabilized reference oscillator
DUse a temperature-controlled high Q dielectric resonator

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 cosine wave
BA square wave
CA sawtooth wave
DA sine wave

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

SelectAnswer
AA frequency modulation technique that uses non-harmonically related frequencies
BA bandwidth compression technique using Fourier transforms
CA digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
DA digital mode for narrow-band, slow-speed transmissions

41. - E8C07

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

SelectAnswer
A5.76 kHz
B4.8 kHz
C15.36 kHz
D9.6 kHz

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

SelectAnswer
AIf interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
BThe frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
CIf interference is detected by the receiver it will signal the transmitter to change frequencies
DA binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence

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
B78.7 watts
C1977 watts
D420 watts

44. - E9B08

What is the far field of an antenna?

SelectAnswer
AThe region where radiated field strengths are constant
BThe region where radiated power dissipates over a specified time period
CThe region of the ionosphere where radiated power is not refracted
DThe region where the shape of the antenna pattern is independent of distance

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

SelectAnswer
AThe horizontal beamwidth decreases in the downhill direction
BThe main lobe takeoff angle decreases in the downhill direction
CThe horizontal beamwidth increases in the uphill direction
DThe main lobe takeoff angle increases in the downhill direction

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

SelectAnswer
A3 dB
B6 dB
C4 dB
D2 dB

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

SelectAnswer
A450 ohms
B50 ohms
C62 ohms
D75 ohms

48. - E9F01

What is the velocity factor of a transmission line?

SelectAnswer
AThe velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
BThe velocity of the wave in the transmission line divided by the velocity of light in a vacuum
CThe ratio of the characteristic impedance of the line to the terminating impedance
DThe index of shielding for coaxial cable

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

SelectAnswer
AIn fractions of antenna electrical wavelength
BIn fractions of transmission line electrical wavelength
CIn fractions of transmission line electrical frequency
DIn fractions of antenna electrical frequency

50. - E9H08

What is the function of a sense antenna?

SelectAnswer
AIt allows DF antennas to receive signals at different vertical angles
BIt modifies the pattern of a DF antenna array to provide a null in one direction
CIt provides diversity reception that cancels multipath signals
DIt increases the sensitivity of a DF antenna array

Figure E5-1

Figure E7-2