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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

SelectAnswer
AEach transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
BOnly commercial transmitters
COnly the most powerful transmitter
DEach transmitter operating with a duty cycle greater than 50 percent

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

SelectAnswer
AAny amateur license with an FCC Marine or Aircraft endorsement
BAny FCC-issued amateur license
CAn unrestricted Radiotelephone Operator Permit
DOnly General Class or higher amateur licenses

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AFAA tower height limits
BHomeowners associations
CState and local zoning
DUse of wireless devices in vehicles

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

SelectAnswer
ACommunications incidental to the purpose of the amateur service and remarks of a personal nature
BMessages intended for users of the maritime satellite service
CAll these choices are correct
DBusiness-related messages for non-profit organizations

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

SelectAnswer
AData containing personal information
BAuxiliary relay links carrying repeater audio
CTelecommand signals from a space telecommand station
DBinary control characters

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

7. - E1F07

When may an amateur station send a message to a business?

SelectAnswer
AWhen neither the amateur nor his or her employer has a pecuniary interest in the communications
BWhen the total money involved does not exceed $25
CWhen the control operator is employed by the FCC or another government agency
DWhen transmitting international third-party communications

8. - E2A05

What do the letters in a satellite's mode designator specify?

SelectAnswer
AThe location of the ground control station
BPower limits for uplink and downlink transmissions
CThe polarization of uplink and downlink signals
DThe uplink and downlink frequency ranges

9. - E2B08

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70 cm band?

SelectAnswer
ATransmitting on channels shared with cable TV
BTransmitting on the abandoned TV channel 2
CUsing USB and demodulating the signal with a computer sound card
DUsing converted satellite TV dishes

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
B15-second timed transmission sequences with stations alternating based on location
CAll these choices are correct
DUse of special digital modes

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
ARTTY
BPACTOR
CAMTOR
DHellschreiber

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

SelectAnswer
A10 miles to 50 miles
B2500 miles
C100 miles to 300 miles
D1200 miles

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

SelectAnswer
ALong-path and short-path waves
BExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
CRefracted rays and reflected waves
DIndependent waves created in the ionosphere that are elliptically polarized

15. - E3C08

What does the space weather term G5 mean?

SelectAnswer
AModerate solar wind
BWaning sunspot numbers
CAn extreme geomagnetic storm
DVery low solar activity

16. - E4A08

Which of the following measures SWR?

SelectAnswer
AA spectrum analyzer
BAn ohmmeter
CAn antenna analyzer
DA Q meter

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

SelectAnswer
AWhen used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
BThe full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
CWhen used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
DWhen used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

SelectAnswer
AOne-half the maximum sampling buffer size
BThe maximum count value of the analog-to-digital converter
CThe reference voltage of the analog-to-digital converter
DOne-half the maximum sample rate

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

SelectAnswer
ASpurious signals caused by cross-modulation and desensitization from strong adjacent signals
BOscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
CCross-modulation of the desired signal and insufficient audio power to operate the speaker
DOscillator instability and severe audio distortion of all but the strongest received signals

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

SelectAnswer
ARemoval of the CW signal as well as the interfering carrier
BAny nearby signal passing through the DSP system will overwhelm the desired signal
CRinging in the DSP filter will completely remove the spaces between the CW characters
DReceived CW signals will appear to be modulated at the DSP clock frequency

21. - E5A07

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

SelectAnswer
AR/L
BMaximum
CL/R
DMinimum

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

SelectAnswer
AOne exponential period
BAn exponential rate of one
COne time constant
DA time factor of one

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

SelectAnswer
APoint 8
BPoint 3
CPoint 7
DPoint 1

24. - E5D10

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

SelectAnswer
ABy dividing the apparent power by the power factor
BBy multiplying 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
AInsulated gate
BBipolar
CN-type
DP-type

26. - E6B10

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

SelectAnswer
A1
B6
C7
D5

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

SelectAnswer
A2
B5
C4
D6

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

SelectAnswer
AButterworth filters
BElectrolytic capacitors
CSteel-core toroids
DFerrite beads

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

SelectAnswer
AAll these choices are correct
BSmaller circuit area
CShorter circuit-board traces
DComponents have less parasitic inductance and capacitance

30. - E6F05

Which describes an optical shaft encoder?

SelectAnswer
AA device that measures the strength of a beam of light using analog to digital conversion
BA device for generating RTTY signals by means of a rotating light source
CA device that detects rotation of a control by interrupting a light source with a patterned wheel
DA digital encryption device often used to encrypt spacecraft control signals

31. - E7A08

What logical operation does an OR gate perform?

SelectAnswer
AIt produces logic 1 at its output if all inputs are logic 0
BIt produces logic 0 at its output if all inputs are logic 1
CIt only produces logic 0 at its output when all inputs are logic 1
DIt produces logic 1 at its output if any or all inputs are logic 1

32. - E7B02

What is a Class D amplifier?

SelectAnswer
AAn amplifier that uses drift-mode FETs for high efficiency
BA type of amplifier that uses switching technology to achieve high efficiency
CA low power amplifier that uses a differential amplifier for improved linearity
DA frequency doubling amplifier

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

SelectAnswer
AA Phase Inverter Load network
BA network with only three discrete parts
CA Pi-network with an additional series inductor on the output
DA matching network in which all components are isolated from ground

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

SelectAnswer
AA Zener diode
BA varactor diode
CA tunnel diode
DAn SCR

35. - E7E10

How does a diode envelope detector function?

SelectAnswer
ABy sensing the change of reactance in the diode with respect to frequency
BBy rectification and filtering of RF signals
CBy breakdown of the Zener voltage
DBy mixing signals with noise in the transition region of the diode

36. - E7F04

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

SelectAnswer
AMixing products are converted to voltages and subtracted by adder circuits
BSignals are combined in quadrature phase relationship
CVarying quartz crystal characteristics emulated in digital form
DA frequency synthesizer removes the unwanted sidebands

37. - E7G04

What is meant by the "op-amp input offset voltage"?

SelectAnswer
AThe potential between the amplifier input terminals of the op-amp in an open loop condition
BThe output voltage of the op-amp minus its input voltage
CThe differential input voltage needed to bring the open loop output voltage to zero
DThe difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

SelectAnswer
AThrough a neutralizing capacitor
BThrough a capacitive divider
CThrough a tapped coil
DThrough link coupling

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

SelectAnswer
A256 divided by the gain of the input amplifier
B8
C256
D8 multiplied by the gain of the input amplifier

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

SelectAnswer
A0.47
B47
C2.14
D0.214

41. - E8C02

What is the definition of symbol rate in a digital transmission?

SelectAnswer
AThe duration of each bit in a message sent over the air
BThe number of control characters in a message packet
CThe number of characters carried per second by the station-to-station link
DThe rate at which the waveform changes to convey information

42. - E8D02

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

SelectAnswer
AFrequency hopping
BDirect sequence
CPhase compandored spread spectrum
DBinary phase-shift keying

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

SelectAnswer
AThe settings of an antenna tuner at the transmitter
BAntenna height
CThe input power level
DTransmission line length

44. - E9B05

What type of antenna pattern is shown in Figure E9-2?

SelectAnswer
AAzimuth
BRadiation resistance
CElevation
DPolarization

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

SelectAnswer
AIt reflects the standing waves on the antenna elements back to the transmitter
BIt decreases the ground loss
CIt changes the radiation pattern from bidirectional to unidirectional
DIt changes the radiation pattern from horizontal to vertical polarization

46. - E9D07

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

SelectAnswer
AImproved radiation efficiency
BLower Q
CGreater structural strength
DHigher losses

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

SelectAnswer
AThe omega matching system
BThe delta matching system
CThe gamma matching system
DThe stub matching system

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

SelectAnswer
A10.6 meters
B3.5 meters
C4.3 meters
D5.3 meters

49. - E9G08

What is the process of normalization with regard to a Smith chart?

SelectAnswer
AReassigning reactance values with regard to the resistance axis
BReassigning prime center with regard to the reactance axis
CReassigning impedance values with regard to the prime center
DReassigning resistance values with regard to the reactance axis

50. - E9H06

What is the triangulation method of direction finding?

SelectAnswer
AA fixed receiving station uses three different antennas to plot the location of the signal source
BThe geometric angles of sky waves from the source are used to determine its position
CA fixed receiving station plots three headings to the signal source
DAntenna headings from several different receiving locations are used to locate the signal source

Figure E5-1

Figure E6-2

Figure E6-3

Figure E9-2