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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. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

SelectAnswer
AOnly a person with an FCC Marine Radio license grant
BOnly a person named in an amateur station license grant
CAny person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
DAny person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

SelectAnswer
A3 miles
B1 mile
C30 miles
D10 miles

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

SelectAnswer
AOperators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
BA special endorsement must be requested from the FCC
COperators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
DAn environmental impact statement must be filed with the Department of the Interior

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

SelectAnswer
AAn organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
BA person who has volunteered to administer amateur operator license examinations
CA person who has volunteered to prepare amateur operator license examinations
DThe person who has entered into an agreement with the FCC to be the VE session manager

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

SelectAnswer
AOnly on amateur frequencies above 420 MHz
BOnly on amateur frequencies above 50 MHz
COnly on amateur frequencies above 222 MHz
DOnly on amateur frequencies above 144 MHz

8. - E2A03

How is the signal inverted by an inverting linear transponder?

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

9. - E2B10

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

SelectAnswer
ASync amplitude
BSync frequency
CTone amplitude
DTone frequency

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

SelectAnswer
AIn the middle of each band, usually on the national calling frequency
BAt the top of each band, usually in a segment reserved for contests
CIn the middle of the band, usually 25 kHz above the national calling frequency
DIn the weak signal segment of the band, with most of the activity near the calling frequency

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

SelectAnswer
AJT65
BPACTOR III
CMSK144
DOlivia

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
AAnother station you are unable to hear is using the frequency
BThe protocol version you are using is not supported by the digital station
CAll these choices are correct
DYour transmit frequency is incorrect

13. - E3A02

What characterizes libration fading of an EME signal?

SelectAnswer
AA fluttery irregular fading
BThe returning echo is several hertz lower in frequency than the transmitted signal
CA gradual loss of signal as the sun rises
DA slow change in the pitch of the CW signal

14. - E3B11

At what time of day can sporadic E propagation occur?

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

SelectAnswer
AClass M
BClass A
CClass B
DClass X

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

SelectAnswer
AA DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
BA square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
CA high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
DA frequency standard is displayed and the probe is adjusted until the deflection time is accurate

17. - E4B03

Which S parameter is equivalent to forward gain?

SelectAnswer
AS11
BS21
CS22
DS12

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

SelectAnswer
ACapture effect
BFrequency discrimination
CCross-modulation interference
DDesensitization

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

SelectAnswer
AQuieting
BDesensitization
CSquelch gain rollback
DCross-modulation interference

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

SelectAnswer
AAll these choices are correct
BA malfunctioning illuminated advertising display
CArcing contacts in a thermostatically controlled device
DA defective doorbell or doorbell transformer inside a nearby residence

21. - E5A04

What is the magnitude of the impedance of a parallel RLC circuit at resonance?

SelectAnswer
AApproximately equal to inductive reactance
BLow compared to the circuit resistance
CHigh compared to the circuit resistance
DApproximately equal to circuit resistance

22. - E5B05

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

SelectAnswer
AIt becomes the reciprocal
BThe sign is reversed
CIt is shifted by 90 degrees
DIt is unchanged

23. - E5C09

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

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

24. - E5D14

What is reactive power?

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

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

26. - E6B10

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

SelectAnswer
A1
B5
C6
D7

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
AThermal impedance
BPermeability
CReactivity
DResistance

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

SelectAnswer
ANearly infinite gain, very high input impedance, and very low output impedance
BPlate current that is controlled by a control grid
CControlled gain, low noise figure, and constant input and output impedance over the specified frequency range
DThe ability to retrieve information from a single signal even in the presence of other strong signals

30. - E6F06

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

SelectAnswer
AA liquid semiconductor
BAn ordinary metal
CA crystalline semiconductor
DA heavy metal

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

SelectAnswer
AMonostable multivibrator
BT flip-flop
CJ-K flip-flop
DAstable multivibrator

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

SelectAnswer
ALinear amplifiers have high gain resulting in higher harmonic content
BSwitching amplifiers operate at higher voltages
CThe power transistor is at saturation or cutoff most of the time
DSwitching amplifiers use push-pull circuits

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. - E7D04

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

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

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

SelectAnswer
AThe square root of the product of input frequencies
BTwo and four times the original frequency
C1.414 and 0.707 times the input frequency
DThe two input frequencies along with their sum and difference frequencies

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

SelectAnswer
AData storage transfer rate
BSample clock phase noise
CMissing codes and jitter
DReference voltage level and sample width in bits

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

SelectAnswer
A7
B28
C0.07
D14

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. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

SelectAnswer
AA square wave
BA sine wave
CA cosine wave
DA sawtooth wave

40. - E8B09

What is deviation ratio?

SelectAnswer
AThe ratio of the highest audio modulating frequency to the average audio modulating frequency
BThe ratio of the carrier center frequency to the audio modulating frequency
CThe ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
DThe ratio of the audio modulating frequency to the center carrier frequency

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

SelectAnswer
A15.36 kHz
B5.76 kHz
C4.8 kHz
D9.6 kHz

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

SelectAnswer
ASome types of errors can be detected
BFaster transmission rate
CThe signal can overpower interfering signals
DForeign language characters can be sent

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
A420 watts
B78.7 watts
C1977 watts
D286 watts

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

SelectAnswer
A75 degrees
B7.5 degrees
C45 degrees
D25 degrees

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

SelectAnswer
AThe low-angle radiation decreases
BAdditional higher vertical angle lobes will appear
CFewer vertical angle lobes will be present
DThe low-angle radiation increases

46. - E9D01

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

SelectAnswer
A3 dB
B2 dB
C6 dB
D4 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
AConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
BInsert a 1/2 wavelength piece of 300-ohm twinlead 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
DInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

SelectAnswer
ALower loss
BLower velocity factor
CSmaller reflection coefficient
DHigher SWR

49. - E9G04

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

SelectAnswer
AVoltage and impedance
BResistance and voltage
CReactance and voltage
DResistance and reactance

50. - E9H07

Why is RF attenuation used when direction-finding?

SelectAnswer
ATo increase receiver sensitivity
BTo narrow the receiver bandwidth
CTo prevent receiver overload which reduces pattern nulls
DTo compensate for isotropic directivity and the antenna effect of feed lines

Figure E6-2

Figure E7-3

Figure E9-2