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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

SelectAnswer
AGround reflections and scattering make the field strength vary with location
BAll these choices are correct
CThe body reacts to electromagnetic radiation from both the E and H fields
DE field and H field radiation intensity peaks can occur at different locations

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

SelectAnswer
AAt the highest frequency of the channel
BAt the lowest frequency of the channel
COn any frequency where the signal's sidebands are within the channel
DAt the center frequency of the channel

3. - E1B09

Which amateur stations may be operated under RACES rules?

SelectAnswer
AAny FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
BAny FCC-licensed amateur station certified by the responsible civil defense organization for the area served
COnly those club stations licensed to Amateur Extra Class operators
DAny FCC-licensed amateur station except a Technician Class

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

SelectAnswer
A26 dB
B6 dB
C3 dB
D23 dB

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

SelectAnswer
ASend the application form to the FCC and inform the FCC of the grade
BMaintain the application form with the VEC's records
CDestroy the application form
DReturn the application document to the examinee

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

SelectAnswer
ATo provide additional spectrum for personal use
BTo provide temporary operation while awaiting normal licensing
CTo provide for experimental amateur communications
DTo allow regular operation on Land Mobile channels

8. - E2A08

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

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

9. - E2B03

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

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

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

SelectAnswer
AThe 60 meter band channel centered on 5373 kHz
BHF frequencies where digital communications are permitted
CCable TV channels 41 through 43
DFrequencies shared with various unlicensed wireless data services

11. - E2D01

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

SelectAnswer
AWSPR
BAPRS
CMSK144
DHellschreiber

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

SelectAnswer
APSK31
BPACTOR
CRTTY
DMT63

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

SelectAnswer
ASuccessive ionospheric refractions without an intermediate reflection from the ground
BSignals reflected back toward the transmitting station
CPropagation across the geomagnetic equator
DPropagation away from the great circle bearing between stations

15. - E3C11

What does VOACAP software model?

SelectAnswer
AHF propagation
BVHF radio propagation
CAC current and impedance
DAC voltage and impedance

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

SelectAnswer
ALoosely couple the analyzer near the antenna base
BConnect the analyzer via a high-impedance transformer to the antenna
CLoosely couple the antenna and a dummy load to the analyzer
DConnect the antenna feed line directly to the analyzer's connector

17. - E4B02

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

SelectAnswer
AThe full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
BWhen 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
CWhen used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
DWhen used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

SelectAnswer
AAnti-aliasing input filter bandwidth
BCPU register width in bits
CAnalog-to-digital converter sample width in bits
DRAM speed used for data storage

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

SelectAnswer
ASwitch from fast AGC to slow AGC
BDecrease the RF bandwidth of the receiver
CRaise the receiver IF frequency
DIncrease the receiver front end gain

20. - E4E01

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

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

21. - E5A15

Which of the following increases Q for inductors and capacitors?

SelectAnswer
ALower reactance
BLower self-resonant frequency
CLower losses
DHigher self-resonant frequency

22. - E5B12

What is admittance?

SelectAnswer
AThe turns ratio of a transformer
BThe term for the gain of a field effect transistor
CThe inverse of impedance
DThe inverse of Q factor

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

SelectAnswer
APoint 5
BPoint 6
CPoint 4
DPoint 2

24. - E5D01

What is the result of skin effect?

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

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
AP-type
BInsulated gate
CN-type
DBipolar

26. - E6B08

Which of the following is a Schottky barrier diode?

SelectAnswer
AElectrolytic rectifier
BPIN junction
CThermionic emission diode
DMetal-semiconductor junction

27. - E6C03

What is tri-state logic?

SelectAnswer
ALogic devices that utilize ternary math
BProprietary logic devices manufactured by Tri-State Devices
CLow-power logic devices designed to operate at 3 volts
DLogic devices with 0, 1, and high-impedance output states

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

SelectAnswer
AExcitation current
BMagnetizing current
CDirect current
DStabilizing current

29. - E6E02

Which of the following device packages is a through-hole type?

SelectAnswer
ADIP
BBall grid array
CPLCC
DSOT

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt decreases
BIt stays the same
CIt becomes unstable
DIt increases

31. - E7A04

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

SelectAnswer
A1
B8
C2
D4

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

SelectAnswer
ASignal inversion
BSignal distortion and excessive bandwidth
CReduced intermodulation products
DIncreased overall intelligibility

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

SelectAnswer
AIt is a band-pass filter
BIt is a high-pass filter
CIt is a low-pass filter
DIt is a notch filter

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

SelectAnswer
AA shunt current source
BA series current source
CA series regulator
DA shunt regulator

35. - E7E01

Which of the following can be used to generate FM phone emissions?

SelectAnswer
AA balanced modulator on the audio amplifier
BA reactance modulator on the final amplifier
CA reactance modulator on the oscillator
DA balanced modulator on the oscillator

36. - E7F07

What function is performed by a Fast Fourier Transform?

SelectAnswer
AConverting digital signals to analog form
BConverting analog signals to digital form
CConverting 8-bit data to 16-bit data
DConverting digital signals from the time domain to the frequency domain

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

SelectAnswer
AThe gain of the amplifier at a filter's cutoff frequency
BThe frequency at which the open-loop gain of the amplifier equals one
CThe maximum frequency for a filter circuit using that type of amplifier
DThe frequency at which the amplifier's offset voltage is zero

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

SelectAnswer
AThrough a quartz crystal
BThrough link coupling
CThrough a tapped coil
DThrough a neutralizing capacitor

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

SelectAnswer
APower factor
BPeak envelope power
CTotal harmonic distortion
DReciprocal mixing

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

SelectAnswer
A3
B2000
C6000
D1/3

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
ABaud is only used for RTTY
BThey are the same
CSymbol rate is only used for packet-based modes
DBaud is twice the symbol rate

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. - E9A13

What term describes station output, taking into account all gains and losses?

SelectAnswer
AHalf-power bandwidth
BEffective radiated power
CApparent power
DPower factor

44. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

SelectAnswer
A14 dB
B18 dB
C12 dB
D24 dB

45. - E9C09

Which of the following describes a G5RV antenna?

SelectAnswer
AA phased array antenna consisting of multiple loops
BA multi-band trap antenna
CA wide band dipole using shorted coaxial cable for the radiating elements and fed with aÿ4:1 balun
DA multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

SelectAnswer
A3 dB
B4 dB
C6 dB
D2 dB

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

SelectAnswer
AInsert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
BInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
CConnect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
DConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna

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
A4.3 meters
B10.6 meters
C3.5 meters
D5.3 meters

49. - E9G09

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

SelectAnswer
AAntenna-length circles
BCoaxial-length circles
CStanding wave ratio circles
DRadiation-pattern circles

50. - E9H08

What is the function of a sense antenna?

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

Figure E5-1

Figure E9-1