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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
BMica
CZinc oxide
DUranium Hexafluoride

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

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

SelectAnswer
AMilitary Auxiliary Radio System (MARS) channels
BSpecific local government channels
CSpecific segments in the amateur service MF, HF, VHF and UHF bands
DAll amateur service frequencies authorized to the control operator

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

SelectAnswer
ANone
BOnly the top 3 kHz
CThe entire band
DOnly the bottom 3 kHz

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

SelectAnswer
AA label with the name, address, and telephone number of the control operator
BA photocopy of the station license
CA label with the name, address, and telephone number of the station licensee
DAll these choices are correct

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
BAll these choices are correct
CThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
DIssue the examinee the new or upgrade license

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AOnly Technician, General, Advanced or Amateur Extra Class operators
BOnly General, Advanced or Amateur Extra Class operators
COnly Amateur Extra Class operators
DAny licensed amateur operator

8. - E2A03

How is the signal inverted by an inverting linear transponder?

SelectAnswer
AThe signal is reduced to I and Q components and the Q component is filtered out
BThe signal is passed through a mixer and the difference rather than the sum is transmitted
CThe signal is detected and remodulated on the reverse sideband
DThe signal is passed through a non-linear filter

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 IF converter
BA special notch filter to remove synchronization pulses
CNo other hardware is needed
DA special front end limiter

10. - E2C05

What is the function of a DX QSL Manager?

SelectAnswer
ATo handle the receiving and sending of confirmation cards for a DX station
BTo run a net to allow many stations to contact a rare DX station
CTo allocate frequencies for DXpeditions
DTo relay calls to and from a DX station

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

SelectAnswer
AMSK144
BAPRS
CWSPR
DHellschreiber

12. - E2E08

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

SelectAnswer
APACTOR
BAMTOR
CHellschreiber
DRTTY

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
ARTTY
BCW
CSSB
DFM

14. - E3B11

At what time of day can sporadic E propagation occur?

SelectAnswer
AOnly around sunset and sunrise
BOnly in hours of darkness
COnly around sunset
DAny time

15. - E3C01

What does the radio communication term "ray tracing" describe?

SelectAnswer
AModeling a radio wave's path through the ionosphere
BDetermining the radiation pattern from an array of antennas
CEvaluating high voltage sources for x-rays
DThe process in which an electronic display presents a pattern

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

SelectAnswer
ALogic analyzer
BNetwork analyzer
CBit error rate tester
DModulation monitor

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
AThe relative time between measurements
BThe port or ports at which measurements are made
CRelative quality of the data
DFrequency order of the measurements

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
A15.210 MHz
B14.445 MHz
C14.755 MHz
D13.845 MHz

19. - E4D03

How can intermodulation interference between two repeaters occur?

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

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

SelectAnswer
AYou are receiving skywave signals from a distant station
BNearby corroded metal joints are mixing and re-radiating the broadcast signals
CYour station receiver IF amplifier stage is defective
DOne or more of the broadcast stations is transmitting an over-modulated signal

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

SelectAnswer
AIt equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
BIt is at a minimum
CIt equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
DIt is at a maximum

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 leads current by 90 degrees
CVoltage and current are 180 degrees out of phase
DCurrent leads voltage by 90 degrees

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

SelectAnswer
AMaidenhead grid
BFaraday grid
CElliptical coordinates
DRectangular coordinates

24. - E5D01

What is the result of skin effect?

SelectAnswer
AThermal effects on the surface of the conductor decrease the impedance
BAs frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
CAs frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
DThermal effects on the surface of the conductor increase the impedance

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

SelectAnswer
AThey are both low impedance
BAn FET has lower input impedance
CAn FET has higher input impedance
DThey are both high impedance

26. - E6B10

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

SelectAnswer
A6
B5
C7
D1

27. - E6C08

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

SelectAnswer
A1
B4
C3
D2

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
AFerrite beads
BSteel-core toroids
CButterworth filters
DElectrolytic capacitors

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

SelectAnswer
A-20 dBm
B-10 dB
C2 dB
D44 dBm

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

SelectAnswer
AA crystalline semiconductor
BA heavy metal
CA liquid semiconductor
DAn ordinary metal

31. - E7A07

What logical operation does a NAND gate perform?

SelectAnswer
AIt produces logic 1 at its output only when all inputs are logic 1
BIt produces logic 0 at its output only when all inputs are logic 0
CIt produces logic 0 at its output only when all inputs are logic 1
DIt produces logic 0 at its output if some but not all inputs are logic 1

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

SelectAnswer
ACreation of parasitic oscillations
BTransmission of spurious signals
CLow efficiency
DAll these choices are correct

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

SelectAnswer
AA crystal filter
BA DSP filter
CAn L-C filter
DA cavity filter

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

SelectAnswer
ATo provide fixed DC bias for Q1
BTo self-resonate at the hum frequency
CIt is a brute force filter for the output
DIt bypasses rectifier output ripple around D1

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

SelectAnswer
AAn FM generator circuit
BA circuit for detecting FM signals
CA circuit for filtering two closely adjacent signals
DAn automatic band-switching circuit

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
BAn adaptive filter
CA crystal-lattice filter
DA phase-inverting filter

37. - E7G02

What is ringing in a filter?

SelectAnswer
AUndesired oscillations added to the desired signal
BA reduction in high frequency response
CAn echo caused by a long time delay
DPartial cancellation of the signal over a range of frequencies

38. - E7H15

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

SelectAnswer
AComparison of two digital input signals, digital pulse counter
BFrequency synthesis, FM demodulation
CPhotovoltaic conversion, optical coupling
DWide-band AF and RF power amplification

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

SelectAnswer
ALevel shifting
BHarmonic regeneration
CPhase reversal
DSuccessive approximation

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

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. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

SelectAnswer
A-30 dB
B-20 dB
C+15 dB
D+10 dB

43. - E9A05

What is included in the total resistance of an antenna system?

SelectAnswer
ARadiation resistance plus loss resistance
BRadiation resistance plus transmission resistance
CTransmission-line resistance plus radiation resistance
DRadiation resistance plus space impedance

44. - E9B10

What is the principle of a Method of Moments analysis?

SelectAnswer
AA wire is modeled as a series of segments, each having a distinct value of voltage across it
BA wire is modeled as a single sine-wave current generator
CA wire is modeled as a single sine-wave voltage source
DA wire is modeled as a series of segments, each having a uniform value of current

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

SelectAnswer
AIt is decreased
BIt is unchanged if the loading coil is located at the feed point
CIt is increased
DIt is unchanged if the loading coil is located at a voltage maximum point

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

SelectAnswer
ADouble-bazooka match
BGamma match
CAll these choices are correct
DHairpin match

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AVery high impedance
BThe same as the generator output impedance
CThe same as the characteristic impedance of the transmission line
DVery low impedance

49. - E9G02

What type of coordinate system is used in a Smith chart?

SelectAnswer
AResistance lines and reactance chords
BVoltage circles and current arcs
CResistance circles and reactance arcs
DVoltage lines and current chords

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
AForward gain compared to the gain in the reverse direction
BRelative directivity compared to isotropic
CRelative directivity compared to a dipole
DForward gain compared to average gain over the entire hemisphere

Figure E6-2

Figure E6-3

Figure E7-2