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

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

SelectAnswer
AThe amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
BIts operation must be approved by the master of the ship or the pilot in command of the aircraft
CThe amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
DThe amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AUse of wireless devices in vehicles
BFAA tower height limits
CHomeowners associations
DState and local zoning

4. - E1C04

What is meant by IARP?

SelectAnswer
AAn indication of increased antenna reflected power
BA forecast of intermittent aurora radio propagation
CThe internal amateur radio practices policy of the FCC
DAn international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

SelectAnswer
AA sentence of up to one year in prison
BA fine of up to $1000 per occurrence
CAll these choices are correct
DRevocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant

7. - E1F07

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

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

8. - E2A08

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

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

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

SelectAnswer
ASync amplitude
BTone amplitude
CSync frequency
DTone frequency

10. - E2C04

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

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

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

SelectAnswer
AAcknowledgement
BDisconnect
CUnnumbered Information
DConnect

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

SelectAnswer
ARTTY
BPSK31
CPACTOR
DMFSK

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
ASSB
BRTTY
CFM
DCW

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

SelectAnswer
AThey become phase locked
BThey become elliptically polarized
CThey are bent toward the magnetic poles
DThey become depolarized

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

SelectAnswer
AEastward
BWestward
CSouthward
DNorthward

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

SelectAnswer
AA spectrum analyzer
BA time-domain reflectometer
CA wattmeter
DA logic analyzer

17. - E4B02

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

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

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

SelectAnswer
A-155 dBm
B-148 dBm
C-174 dBm
D-164 dBm

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

SelectAnswer
ADecrease the RF bandwidth of the receiver
BIncrease the receiver front end gain
CSwitch from fast AGC to slow AGC
DRaise the receiver IF frequency

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

SelectAnswer
ADifferential-mode current
BReactive current only
CReturn current
DCommon-mode current

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

SelectAnswer
A157.8 Hz
B47.3 kHz
C23.67 kHz
D315.6 Hz

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

SelectAnswer
A68.2 degrees with the voltage leading the current
B68.2 degrees with the voltage lagging the current
C14.0 degrees with the voltage lagging the current
D14.0 degrees with the voltage leading the current

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

SelectAnswer
AThe X axis represents the resistive component and the Y axis represents the reactive component
BThe X axis represents the reactive component and the Y axis represents the resistive component
CThe X axis represents the phase angle and the Y axis represents the magnitude
DThe X axis represents the magnitude and the Y axis represents the phase angle

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

SelectAnswer
A0.5
B1.414
C0.866
D1.73

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
AN-type
BInsulated gate
CP-type
DBipolar

26. - E6B10

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

SelectAnswer
A6
B5
C1
D7

27. - E6C08

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

SelectAnswer
A1
B2
C4
D3

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

SelectAnswer
ARF susceptance would increase
BMagnetic flux would increase with frequency
CHarmonics and distortion could result
DTemporary changes of the core permeability could result

29. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

SelectAnswer
A300 ohms
B450 ohms
C50 ohms
D10 ohms

30. - E6F04

What is the photovoltaic effect?

SelectAnswer
AThe tendency of a battery to discharge when exposed to light
BThe conversion of voltage to current when exposed to light
CThe conversion of light to electrical energy
DThe conversion of electrical energy to mechanical energy

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

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

SelectAnswer
AHigh filament voltage
BLow bandwidth
CLow input impedance
DHigh power gain

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

SelectAnswer
AGreater transformation range
BDoes not require a capacitor
CHigher efficiency
DGreater harmonic suppression

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

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

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

SelectAnswer
APhase comparator
BProduct detector
CPhase detector
DDiscriminator

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

SelectAnswer
AProcessor latency
BSample width in bits
CSample clock phase noise
DSample rate

37. - E7G04

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

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

SelectAnswer
AIncrease the bias voltage
BReduce noise on the oscillator's power supply
CUse NP0 capacitors
DMechanically isolate the oscillator circuitry from its enclosure

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

SelectAnswer
ALower the input bandwidth to increase the effective resolution
BRemove harmonics from the output caused by the discrete analog levels generated
CImprove accuracy by removing out-of-sequence codes from the input
DAll these choices are correct

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
A6000
B1/3
C2000
D3

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
AThey are the same
BSymbol rate is only used for packet-based modes
CBaud is twice the symbol rate
DBaud is only used for RTTY

42. - E8D08

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

SelectAnswer
ABaud rate
BRepeat Request Rate (RRR)
CIntermodulation Distortion (IMD)
DSignal-to-noise ratio

43. - E9A13

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

SelectAnswer
APower factor
BEffective radiated power
CHalf-power bandwidth
DApparent power

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. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

SelectAnswer
A300 ohms
B50 ohms
C72 ohms
D450 ohms

46. - E9D12

Which of the following would provide the best RF ground for your station?

SelectAnswer
AAn electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
BA 50-ohm resistor connected to ground
CAn electrically short connection to a metal water pipe
DAn electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

SelectAnswer
AThe stub match
BThe delta match
CThe epsilon match
DThe gamma 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
AThe same as the generator output impedance
BThe same as the characteristic impedance of the transmission line
CVery low impedance
DVery high impedance

49. - E9G03

Which of the following is often determined using a Smith chart?

SelectAnswer
ATrigonometric functions
BImpedance and SWR values in transmission lines
CBeam headings and radiation patterns
DSatellite azimuth and elevation bearings

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

SelectAnswer
ABy winding adjacent turns in opposing directions
BBy reducing the permeability of the loop shield
CBy utilizing high impedance wire for the coupling loop
DBy increasing the number of turns and/or the area

Figure E6-2

Figure E6-3

Figure E9-1