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

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

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

SelectAnswer
A100 watts PEP
B50 watts PEP
C1 watt EIRP (Equivalent isotropic radiated power)
D5 watts EIRP (Equivalent isotropic radiated power)

3. - E1B01

Which of the following constitutes a spurious emission?

SelectAnswer
AAny transmitted signal that unintentionally interferes with another licensed radio station
BAn emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
CAn amateur station transmission made without the proper call sign identification
DA signal transmitted to prevent its detection by any station other than the intended recipient

4. - E1C02

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

SelectAnswer
AAll these choices are correct
BCommunications incidental to the purpose of the amateur service and remarks of a personal nature
CBusiness-related messages for non-profit organizations
DMessages intended for users of the maritime satellite service

5. - E1D01

What is the definition of telemetry?

SelectAnswer
ATwo-way transmissions of data
BOne-way transmission of measurements at a distance from the measuring instrument
CTwo-way transmissions in excess of 1000 feet
DOne-way transmission that initiates, modifies, or terminates the functions of a device at a distance

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

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

8. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

SelectAnswer
AAn isotropic antenna
BA circularly polarized antenna
CA log-periodic dipole array
DA linearly polarized antenna

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

SelectAnswer
AElapsed time
BSpecific tone frequencies
CA two-tone signal
DSpecific tone amplitudes

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. - E2D05

What is one advantage of the JT65 mode?

SelectAnswer
APermits fast-scan TV transmissions over narrow bandwidth
BUses only a 65 Hz bandwidth
CThe ability to decode signals which have a very low signal-to-noise ratio
DEasily copied by ear if necessary

12. - E2E06

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

SelectAnswer
A300 baud
B110 baud
C48 baud
D1200 baud

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

SelectAnswer
AWarm and cold fronts
BSprites and jets
CLightning discharges
DGrayline

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
AOnly 160 meters to 40 meters
BOnly 30 meters to 10 meters
C160 meters to 10 meters
D6 meters to 2 meters

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

SelectAnswer
AIt decreases
BIt peaks at roughly 14 MHz
CIt stays the same
DIt increases

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

SelectAnswer
AIt prevents oscillation in a low-frequency counter circuit
BIt divides a higher frequency signal so a low-frequency counter can display the input frequency
CIt multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
DIt amplifies low-level signals for more accurate counting

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

SelectAnswer
AShort circuit, open circuit, and resonant circuit
B50 ohms, 75 ohms, and 90 ohms
CShort circuit, open circuit, and 50 ohms
D50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

SelectAnswer
AThe theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
BThe noise figure of a 1 Hz bandwidth receiver
CThe minimum detectable signal as a function of receive frequency
DThe galactic noise contribution to minimum detectable signal

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

SelectAnswer
AA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
BSignals less than 40 dBm will not generate audible third-order intermodulation products
CA pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
DThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

SelectAnswer
AA whining type noise that continually pulses off and on
BA clicking noise at intervals of a few seconds
CThe appearance of unstable modulated or unmodulated signals at specific frequencies
DA loud AC hum in the audio output of your station receiver

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

SelectAnswer
ACapacitance
BResonance
CResistance
DConductance

22. - E5B05

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

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

23. - E5C06

What does the impedance 50-j25 represent?

SelectAnswer
A50 ohms resistance in series with 25 ohms inductive reactance
B50 ohms resistance in series with 25 ohms capacitive reactance
C25 ohms resistance in series with 50 ohms capacitive reactance
D25 ohms resistance in series with 50 ohms inductive reactance

24. - E5D14

What is reactive power?

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

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

SelectAnswer
AIn high-power audio circuits
BIn microwave circuits
CIn very low-frequency RF circuits
DIn high-current rectifier circuits

26. - E6B09

What is a common use for point-contact diodes?

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

27. - E6C09

What is a Programmable Logic Device (PLD)?

SelectAnswer
AProgrammable equipment used for testing digital logic integrated circuits
BA type of transistor whose gain can be changed by digital logic circuits
CA programmable collection of logic gates and circuits in a single integrated circuit
DA logic circuit that can be modified during use

28. - E6D04

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

SelectAnswer
ACobalt and aluminum
BFerrite and brass
CPolystyrene and polyethylene
DTeflon and Delrin

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

SelectAnswer
AAxial lead
BRadial lead
CSurface mount
DTO-220

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

SelectAnswer
AOptoisolators provide a low impedance link between a control circuit and a power circuit
BOptoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
COptoisolators eliminate the effects of reflected light in the control circuit
DOptoisolators provide impedance matching between the control circuit and power circuit

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

SelectAnswer
A2
B8
C1
D4

32. - E7B08

How can an RF power amplifier be neutralized?

SelectAnswer
ABy feeding an in-phase component of the output back to the input
BBy reducing the driving power
CBy increasing the driving power
DBy feeding a 180-degree out-of-phase portion of the output back to the input

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
AAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
BTwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
CTwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
DA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

SelectAnswer
AEqualize the voltage across each capacitor
BAll these choices are correct
CDischarge the capacitors when voltage is removed
DProvide a minimum load on the supply

35. - E7E07

What is meant by the term "baseband" in radio communications?

SelectAnswer
AThe frequency range occupied by a message signal prior to modulation
BThe basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
CThe lowest frequency band that the transmitter or receiver covers
DThe unmodulated bandwidth of the transmitted signal

36. - E7F13

What is the function of taps in a digital signal processing filter?

SelectAnswer
AProvide access for debugging software
BTo reduce excess signal pressure levels
CProvide incremental signal delays for filter algorithms
DSelect the point at which baseband signals are generated

37. - E7G08

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

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

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

39. - E8A05

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

SelectAnswer
AA D'Arsonval meter
BAn absorption wave meter
CA true-RMS calculating meter
DA grid dip meter

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

SelectAnswer
A3
B1000
C3000
D0.3

41. - E8C02

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

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

42. - E8D08

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

SelectAnswer
ABaud rate
BSignal-to-noise ratio
CRepeat Request Rate (RRR)
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
ADistance from the transmitter
BSoil conductivity
CTake-off angle
DThe standing wave ratio

44. - E9B01

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

SelectAnswer
A25 degrees
B50 degrees
C30 degrees
D75 degrees

45. - E9C10

Which of the following describes a Zepp antenna?

SelectAnswer
AAn omni-directional antenna commonly used for satellite communications
BAn end-fed dipole antenna
CA dipole constructed from zip cord
DA vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
ASolid wire
BResistive wire, such as spark plug wire
CWide flat copper strap
DStranded wire

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 gamma matching system
CThe delta matching system
DThe stub matching system

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AThe same as the characteristic impedance of the line
BVery low impedance
CThe same as the output impedance of the generator
DVery high impedance

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

SelectAnswer
AResistance and reactance
BVoltage and impedance
CReactance and voltage
DResistance and voltage

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

SelectAnswer
AIt eliminates tracking errors caused by strong out-of-band signals
BIt increases signal strength by providing a better match to the feed line
CIt adds capacitive loading, increasing the bandwidth of the antenna
DIt eliminates unbalanced capacitive coupling to the surroundings, improving the nulls

Figure E9-1