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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

SelectAnswer
AOnly commercial transmitters
BOnly the most powerful transmitter
CEach transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
DEach transmitter operating with a duty cycle greater than 50 percent

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
AAn unrestricted Radiotelephone Operator Permit
BOnly General Class or higher amateur licenses
CAny FCC-issued amateur license
DAny amateur license with an FCC Marine or Aircraft endorsement

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

SelectAnswer
AA form FSD-15 must be submitted to the Department of the Interior
BA proposal must be submitted to the National Park Service
CAn Environmental Assessment must be submitted to the FCC
DA letter of intent must be filed with the Environmental Protection Agency

4. - E1C04

What is meant by IARP?

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

5. - E1D03

What is a space telecommand station?

SelectAnswer
AAn amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
BAn amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
CAn amateur station that transmits communications to initiate, modify or terminate functions of a space station
DAn amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

SelectAnswer
AMinimum passing score of 80%
BMinimum passing score of 77%
CMinimum passing score of 74%
DMinimum passing score of 70%

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AOnly Technician, General, Advanced or Amateur Extra Class operators
BAny licensed amateur operator
COnly General, Advanced or Amateur Extra Class operators
DOnly Amateur Extra Class operators

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

SelectAnswer
ADigipeating
BNode hopping
CStore-and-forward
DMulti-satellite relaying

9. - E2B04

How is color information sent in analog SSTV?

SelectAnswer
AColor information is sent on a 2.8 kHz subcarrier
BColor is sent in a color burst at the end of each line
CColor is amplitude modulated on the frequency modulated intensity signal
DColor lines are sent sequentially

10. - E2C10

Why might a DX station state that they are listening on another frequency?

SelectAnswer
ABecause the DX station may be transmitting on a frequency that is prohibited to some responding stations
BAll these choices are correct
CTo improve operating efficiency by reducing interference
DTo separate the calling stations from the DX station

11. - E2D09

What type of modulation is used for JT65 contacts?

SelectAnswer
ARTTY
BIEEE 802.11
CPSK
DMulti-tone AFSK

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

SelectAnswer
AFinal Error Correction
BForward Error Correction
CFatal Error Correction
DFirst Error Correction

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

SelectAnswer
ADust devil
BThe jet stream
CWind shear
DTemperature inversion

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

SelectAnswer
A7500 miles
B2500 miles
C1000 miles
D5000 miles

15. - E3C13

What type of polarization is best for ground-wave propagation?

SelectAnswer
AHorizontal
BCircular
CElliptical
DVertical

16. - E4A11

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

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

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

SelectAnswer
A50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
BShort circuit, open circuit, and 50 ohms
C50 ohms, 75 ohms, and 90 ohms
DShort circuit, open circuit, and resonant circuit

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

SelectAnswer
AIt improves sensitivity by reducing front end noise
BAll these choices are correct
CIt improves dynamic range by attenuating strong signals near the receive frequency
DIt improves intelligibility by using low Q circuitry to reduce ringing

19. - E4D11

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

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

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

SelectAnswer
AAll these choices are correct
BPower line noise
CIgnition noise
DBroadband white noise

21. - E5A16

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries and C is 10 picofarads?

SelectAnswer
A23.5 MHz
B7.12 kHz
C23.5 kHz
D7.12 MHz

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

SelectAnswer
AVoltage and current are in phase
BVoltage and current are 180 degrees out of phase
CCurrent leads voltage by 90 degrees
DVoltage leads current by 90 degrees

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

SelectAnswer
AFar field diagram
BPhasor diagram
CVenn diagram
DNear field diagram

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

SelectAnswer
AIn a circle around the conductor
BIn a direction opposite to the current
CIn the same direction as the current
DIn all directions; omni-directional

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
AAn FET has lower input impedance
BThey are both high impedance
CThey are both low impedance
DAn FET has higher input impedance

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

SelectAnswer
AExcessive junction temperature
BInsufficient forward voltage
CCharge carrier depletion
DExcessive inverse voltage

27. - E6C08

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

SelectAnswer
A1
B3
C2
D4

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

SelectAnswer
AMechanical deformation of material by the application of a voltage
BIncreased conductivity in the presence of light
CMechanical deformation of material by the application of a magnetic field
DGeneration of electrical energy in the presence of light

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

SelectAnswer
ASurface mount
BAxial lead
CRadial lead
DTO-220

30. - E6F06

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

SelectAnswer
AAn ordinary metal
BA heavy metal
CA crystalline semiconductor
DA liquid semiconductor

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
APositive Logic
BNegative logic
CReverse Logic
DAssertive Logic

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

SelectAnswer
ABecause they are relatively far in frequency from the desired signal
BBecause they maintain the sidebands, thus causing multiple duplicate signals
CBecause they are relatively close in frequency to the desired signal
DBecause they invert the sidebands causing distortion

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

SelectAnswer
AThe gain of the RF stage preceding the filter
BThe relative frequencies of the individual crystals
CThe DC voltage applied to the quartz crystal
DThe amplitude of the signals passing through the filter

34. - E7D07

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

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

35. - E7E01

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

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

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

SelectAnswer
AAn elliptical filter
BA Hilbert-transform filter
CAn adaptive filter
DA notch filter

37. - E7G12

What is an operational amplifier?

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

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

SelectAnswer
AProvide the crystal with a specified parallel capacitance
BProvide the crystal with a specified parallel inductance
CBias the crystal at a specified current
DBias the crystal at a specified voltage

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

SelectAnswer
A100 to 1
B1 to 1
C25 to 1
D2.5 to 1

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
ATwo or more information streams are merged into a baseband, which then modulates the transmitter
BThe transmitted signal jumps from band to band at a predetermined rate
CThe transmitted signal is divided into packets of information
DTwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C02

What is the definition of symbol rate in a digital transmission?

SelectAnswer
AThe number of control characters in a message packet
BThe duration of each bit in a message sent over the air
CThe rate at which the waveform changes to convey information
DThe number of characters carried per second by the station-to-station link

42. - E8D08

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

SelectAnswer
AIntermodulation Distortion (IMD)
BSignal-to-noise ratio
CRepeat Request Rate (RRR)
DBaud rate

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

SelectAnswer
AThe input power level
BThe settings of an antenna tuner at the transmitter
CAntenna height
DTransmission line length

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

SelectAnswer
AThey are the same
BThe radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
CThe total amount of radiation from the directional antenna is stronger by its front-to-back ratio
DThe total amount of radiation from the directional antenna is increased by the gain of the antenna

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

SelectAnswer
AA Figure-8 broadside to the axis of the array
BOmni-directional
CCardioid
DA Figure-8 end-fire along the axis of the array

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
AStranded wire
BWide flat copper strap
CResistive wire, such as spark plug wire
DSolid wire

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

SelectAnswer
A450 ohms
B75 ohms
C50 ohms
D62 ohms

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

SelectAnswer
A8.5 meters
B10.6 meters
C13.3 meters
D7.0 meters

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

SelectAnswer
AThe resistance axis
BThe voltage axis
CThe current axis
DThe reactance axis

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

SelectAnswer
AIt eliminates tracking errors caused by strong out-of-band signals
BIt adds capacitive loading, increasing the bandwidth of the antenna
CIt increases signal strength by providing a better match to the feed line
DIt eliminates unbalanced capacitive coupling to the surroundings, improving the nulls

Figure E6-3

Figure E7-2

Figure E9-3