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

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1. - E0A08

What does SAR measure?

SelectAnswer
ASignal Amplification Rating
BThe rate of RF energy reflected from stationary terrain
CSynthetic Aperture Ratio of the human body
DThe rate at which RF energy is absorbed by the body

2. - E1A07

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

SelectAnswer
A1 watt EIRP (Equivalent isotropic radiated power)
B100 watts PEP
C5 watts EIRP (Equivalent isotropic radiated power)
D50 watts PEP

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AFAA tower height limits
BUse of wireless devices in vehicles
CHomeowners associations
DState and local zoning

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

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

SelectAnswer
AThe VE session manager
BThe VEC coordinating the session
CEach administering VE
DThe FCC

7. - E1F08

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

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

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

SelectAnswer
ATo prevent the satellite from emitting out-of-band signals
BTo prevent creating errors in the satellite telemetry
CTo avoid interfering with terrestrial QSOs
DTo avoid reducing the downlink power to all other users

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

SelectAnswer
ABy scanning lines from left to right in one field and right to left in the next
BBy scanning two fields simultaneously
CBy scanning odd numbered lines in one field and even numbered lines in the next
DBy scanning each field from bottom to top

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

11. - E2D06

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

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

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

SelectAnswer
AThe protocol version you are using is not supported by the digital station
BAll these choices are correct
CAnother station you are unable to hear is using the frequency
DYour transmit frequency is incorrect

13. - E3A12

What is the cause of auroral activity?

SelectAnswer
AAn extreme low-pressure area in the polar regions
BThe interaction in the F2 layer between the solar wind and the Van Allen belt
CMeteor showers concentrated in the extreme northern and southern latitudes
DThe interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

SelectAnswer
A20 meters
B80 meters
C6 meters
D10 meters

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

SelectAnswer
ATwice as great
BFour times as great
C10 percent greater
D50 percent greater

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

SelectAnswer
AModulation monitor
BLogic analyzer
CNetwork analyzer
DBit error rate tester

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

SelectAnswer
A125 watts
B25 watts
C100 watts
D75 watts

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

SelectAnswer
A14.445 MHz
B13.845 MHz
C14.755 MHz
D15.210 MHz

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

SelectAnswer
AOdd-order products are an indication of poor image rejection
BOdd-order intermodulation produces three products for every input signal within the band of interest
COdd-order products of two signals in the band of interest are also likely to be within the band
DOdd-order products overload the IF filters

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

SelectAnswer
AUse of braided shielding material
BLow inductance ground connections at both ends of the shield
CTying all ground connections to a common point resulting in differential-mode currents in the shield
DCommon-mode currents on the shield and conductors

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

SelectAnswer
A218.3 kHz
B436.6 kHz
C31.4 kHz
D15.7 kHz

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

SelectAnswer
A76 degrees with the voltage lagging the current
B14 degrees with the voltage lagging the current
C14 degrees with the voltage leading the current
D76 degrees with the voltage leading the current

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

SelectAnswer
AOn a line through the origin, slanted at 45 degrees
BOn a horizontal line, offset vertically above the horizontal axis
COn the horizontal axis
DOn the vertical axis

24. - E5D14

What is reactive power?

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

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

26. - E6B06

Which of the following is a common use of a Schottky diode?

SelectAnswer
AAs a VHF/UHF mixer or detector
BAs a constant voltage reference in a power supply
CAs a variable capacitance in an automatic frequency control circuit
DAs a rectifier in high current power supplies

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

SelectAnswer
A1
B4
C2
D3

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
AThermal impedance
BReactivity
CPermeability
DResistance

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. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

SelectAnswer
AA lens and a photomultiplier
BAn amplitude modulated helium-neon laser
CAn LED and a phototransistor
DA frequency modulated helium-neon laser

31. - E7A08

What logical operation does an OR gate perform?

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

32. - E7B12

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

SelectAnswer
AEmitter follower
BCommon emitter
CCommon base
DCommon collector

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

34. - E7D03

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

SelectAnswer
AA tunnel diode
BAn SCR
CA Zener diode
DA varactor diode

35. - E7E10

How does a diode envelope detector function?

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

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 the same rate as the highest frequency component of the signal
BAt four times the rate of 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. - E7G12

What is an operational amplifier?

SelectAnswer
AA high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
BA digital audio amplifier whose characteristics are determined by components external to the amplifier
CA RF amplifier used in the UHF and microwave regions
DAn amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

38. - E7H13

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

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

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 true-RMS calculating meter
CA D'Arsonval meter
DA grid dip meter

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

SelectAnswer
AEME
BExtremely low-power contacts
CHigh-speed digital modes
DOFDM signals are not allowed on amateur bands

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

SelectAnswer
ATo minimize bandwidth
BTo simplify modulation
CAll these choices are correct
DTo improve carrier suppression

42. - E8D08

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

SelectAnswer
ASignal-to-noise ratio
BBaud rate
CIntermodulation Distortion (IMD)
DRepeat Request Rate (RRR)

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
C420 watts
D1977 watts

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

SelectAnswer
A3 dB
B38 dB
C28 dB
D15 dB

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

SelectAnswer
AA center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
BA wideband vertical antenna constructed from precisely tapered aluminum tubing
CA portable antenna erected using two push support poles
DAn end-fed folded dipole antenna

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

SelectAnswer
ATo swamp out harmonics
BTo minimize the Q
CTo lower the radiation angle
DTo minimize losses

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

SelectAnswer
AThe stub match
BThe omega match
CThe gamma match
DThe delta match

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
AVery high impedance
BVery low impedance
CThe same as the output impedance of the generator
DThe same as the characteristic impedance of the line

49. - E9G05

Which of the following is a common use for a Smith chart?

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

50. - E9H06

What is the triangulation method of direction finding?

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

Figure E6-3

Figure E7-1