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. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

SelectAnswer
AEnsure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
BEnsure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
CEnsure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
DEnsure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

SelectAnswer
AThe control operators of all the stations in the system
BThe control operator of the originating station
CThe control operators of all the stations in the system not authenticating the source from which they accept communications
DThe control operator of the packet bulletin board station

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

SelectAnswer
AFile an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
BAll these choices are correct
CCease operation or make changes to the repeater to mitigate the interference
DReduce the repeater antenna HAAT (Height Above Average Terrain)

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

SelectAnswer
A3.0
B1.0
C2.0
D0.5

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

SelectAnswer
AOnly the 40, 20, 17, 15, and 10 meter bands
BAll HF bands
COnly the 40, 20, 17, 15, 12, and 10 meter bands
DOnly the 40, 30, 20, 15, 12, and 10 meter bands

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

SelectAnswer
APhotocopy all examination documents and forward them to the FCC for processing
BIssue the examinee the new or upgrade license
CThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
DAll these choices are correct

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

SelectAnswer
AThe operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
BNone, they must obtain a U.S. license
CFull privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
DAll privileges of the Amateur Extra Class license

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

SelectAnswer
AFrom east to west
BFrom west to east
CFrom south to north
DFrom north to south

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

SelectAnswer
AA special notch filter to remove synchronization pulses
BNo other hardware is needed
CA special front end limiter
DA special IF converter

10. - E2C12

What technique do individual nodes use to form a mesh network?

SelectAnswer
ACustom code plugs for the local trunking systems
BForward error correction and Viterbi codes
CActing as store-and-forward digipeaters
DDiscovery and link establishment protocols

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
CAll these choices are correct
DUse of special digital modes

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

SelectAnswer
ASpread spectrum
BFSK
CDTMF tones modulating an FM signal
DPulse modulation

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

14. - E3B03

What is the best time of day for transequatorial propagation?

SelectAnswer
ALate at night
BNoon
CAfternoon or early evening
DMorning

15. - E3C13

What type of polarization is best for ground-wave propagation?

SelectAnswer
AHorizontal
BElliptical
CCircular
DVertical

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 frequency
CSWR and time
DRF amplitude and time

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

SelectAnswer
AS12
BS11
CS21
DS22

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. - 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 out of phase from airplanes passing overhead
DWhen the signals from the transmitters are reflected in phase from airplanes passing overhead

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. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

SelectAnswer
A47.3 kHz
B315.6 Hz
C157.8 Hz
D23.67 kHz

22. - E5B10

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

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

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

SelectAnswer
APhasor diagram
BVenn diagram
CNear field diagram
DFar field diagram

24. - E5D14

What is reactive power?

SelectAnswer
APower consumed in circuit Q
BWattless, nonproductive power
CPower consumed in wire resistance in an inductor
DPower lost because of capacitor leakage

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

SelectAnswer
ATo protect the substrate from excessive voltages
BTo keep the gate voltage within specifications and prevent the device from overheating
CTo provide a voltage reference for the correct amount of reverse-bias gate voltage
DTo reduce the chance of static damage to the gate

26. - E6B04

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

SelectAnswer
AZener diode
BVaractor diode
CSilicon-controlled rectifier
DTunnel diode

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

SelectAnswer
ALower power consumption
BLower distortion
CImmune to damage from static discharge
DDifferential output capability

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
APermeability
BResistance
CReactivity
DThermal impedance

29. - E6E04

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

SelectAnswer
A10 ohms
B300 ohms
C50 ohms
D450 ohms

30. - E6F10

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

SelectAnswer
ACadmium Sulfide
BSelenium
CCopper oxide
DSilicon

31. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt switches momentarily to the opposite binary state and then returns to its original state after a set time
BIt produces a continuous square wave oscillating between 1 and 0
CIt stores one bit of data in either a 0 or 1 state
DIt maintains a constant output voltage, regardless of variations in the input voltage

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 loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable 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 adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
DThe tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

SelectAnswer
AThe amplitude of the signals passing through the filter
BThe gain of the RF stage preceding the filter
CThe DC voltage applied to the quartz crystal
DThe relative frequencies of the individual crystals

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

SelectAnswer
AMatching of day and night charge rates
BControl of electrolyte levels during battery discharge
CPrevention of battery damage due to overcharge
DPrevention of battery undercharge

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

SelectAnswer
AA beat frequency is generated
BMixer blanking occurs
CSpurious mixer products are generated
DAutomatic limiting occurs

36. - E7F04

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

SelectAnswer
ASignals are combined in quadrature phase relationship
BMixing products are converted to voltages and subtracted by adder circuits
CA frequency synthesizer removes the unwanted sidebands
DVarying quartz crystal characteristics emulated in digital form

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

SelectAnswer
AIt decreases logarithmically with increasing frequency
BIt decreases linearly with increasing frequency
CIt increases linearly with increasing frequency
DIt does not vary with frequency

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

SelectAnswer
APhotovoltaic conversion, optical coupling
BComparison of two digital input signals, digital pulse counter
CWide-band AF and RF power amplification
DFrequency synthesis, FM demodulation

39. - E8A05

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

SelectAnswer
AAn absorption wave meter
BA D'Arsonval meter
CA true-RMS calculating meter
DA grid dip meter

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
AThe transmitted signal is divided into packets of information
BTwo or more information streams are merged into a baseband, which then modulates the transmitter
CThe transmitted signal jumps from band to band at a predetermined rate
DTwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C07

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

SelectAnswer
A15.36 kHz
B4.8 kHz
C5.76 kHz
D9.6 kHz

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

SelectAnswer
ABaudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
BBaudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
CBaudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
DBaudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

43. - E9A01

What is an isotropic antenna?

SelectAnswer
AA spacecraft antenna used to direct signals toward Earth
BA grounded antenna used to measure Earth conductivity
CA theoretical, omnidirectional antenna used as a reference for antenna gain
DA horizontally polarized antenna used to compare Yagi antennas

44. - E9B01

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

SelectAnswer
A50 degrees
B25 degrees
C30 degrees
D75 degrees

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

SelectAnswer
AThe takeoff angle of the lowest elevation lobe decreases
BThe horizontal beamwidth decreases
CThe takeoff angle of the lowest elevation lobe increases
DThe horizontal beamwidth increases

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

SelectAnswer
AHigher losses
BLower Q
CImproved radiation efficiency
DGreater structural strength

47. - E9E08

What is a use for a Wilkinson divider?

SelectAnswer
AIt is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
BIt divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
CIt is used to feed low-impedance loads from a high-impedance source
DIt is used to feed high-impedance antennas from a low-impedance source

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
AZero
BA capacitive reactance
CThe same as the characteristic impedance of the line
DAn inductive reactance

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

SelectAnswer
AStanding wave ratio circles
BAntenna-length circles
CRadiation-pattern circles
DCoaxial-length circles

50. - E9H08

What is the function of a sense antenna?

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

Figure E9-1