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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

SelectAnswer
AMicrowaves often travel long distances by ionospheric reflection
BThe extremely high frequency energy can damage the joints of antenna structures
CThe high gain antennas commonly used can result in high exposure levels
DMicrowaves are ionizing radiation

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

SelectAnswer
A14.349 MHz
B14.100 MHz
C14.149 MHz
D14.070 MHz

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

SelectAnswer
ANo limitations may be placed on antenna size or placement
BAmateur radio operations must be permitted in any private residence
CUse of wireless devices in a vehicle is exempt from regulation
DReasonable accommodations of amateur radio must be made

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

SelectAnswer
AIARP agreement
BAll these choices are correct
CCEPT agreement
DITU reciprocal license

5. - E1D03

What is a space telecommand station?

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

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
AAll these choices are correct
BIssue the examinee the new or upgrade license
CThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
DPhotocopy all examination documents and forward them to the FCC for processing

7. - E1F06

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

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

8. - E2A13

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

SelectAnswer
AMulti-satellite relaying
BStore-and-forward
CNode hopping
DDigipeating

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
ASpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
BAmplitude modulation in which one complete sideband and a portion of the other are transmitted
CA type of modulation in which one sideband is inverted
DNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

SelectAnswer
AAn automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
BA manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
CThe often-prohibited practice of posting one's own call sign and frequency on a spotting network
DThe acceptable practice of manually posting the call signs of stations on a spotting network

11. - E2D09

What type of modulation is used for JT65 contacts?

SelectAnswer
AIEEE 802.11
BRTTY
CPSK
DMulti-tone AFSK

12. - E2E06

What is the most common data rate used for HF packet?

SelectAnswer
A110 baud
B48 baud
C300 baud
D1200 baud

13. - E3A10

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

SelectAnswer
AWind shear
BTemperature inversion
CThe jet stream
DDust devil

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 are bent toward the magnetic poles
CThey become depolarized
DThey become elliptically polarized

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
CThe process in which an electronic display presents a pattern
DEvaluating high voltage sources for x-rays

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

SelectAnswer
ARF amplitude and time
BSWR and frequency
CSWR and time
DRF amplitude and frequency

17. - E4B07

What do the subscripts of S parameters represent?

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

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
BDesensitization
CCross-modulation interference
DFrequency discrimination

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

SelectAnswer
A146.88 MHz and 146.34 MHz
B146.34 MHz and 146.61 MHz
C173.35 MHz and 139.40 MHz
D146.10 MHz and 147.30 MHz

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

SelectAnswer
AA whining type noise that continually pulses off and on
BThe appearance of unstable modulated or unmodulated signals at specific frequencies
CA loud AC hum in the audio output of your station receiver
DA clicking noise at intervals of a few seconds

21. - E5A02

What is resonance in an LC or RLC circuit?

SelectAnswer
AThe highest frequency that will pass current
BThe lowest frequency that will pass current
CThe frequency at which the reactive impedance equals the resistive impedance
DThe frequency at which the capacitive reactance equals the inductive reactance

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

SelectAnswer
A14 degrees with the voltage leading the current
B76 degrees with the voltage lagging the current
C76 degrees with the voltage leading the current
D14 degrees with the voltage lagging the current

23. - E5C05

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

SelectAnswer
APhasor diagram
BVenn diagram
CFar field diagram
DNear field diagram

24. - E5D04

Why are short connections used at microwave frequencies?

SelectAnswer
ATo reduce noise figure
BTo increase neutralizing resistance
CTo increase compensating capacitance
DTo reduce phase shift along the connection

25. - E6A06

What is the beta of a bipolar junction transistor?

SelectAnswer
AThe switching speed
BThe frequency at which the current gain is reduced to 0.707
CThe change in collector current with respect to base current
DThe breakdown voltage of the base to collector junction

26. - E6B06

Which of the following is a common use of a Schottky diode?

SelectAnswer
AAs a rectifier in high current power supplies
BAs a VHF/UHF mixer or detector
CAs a variable capacitance in an automatic frequency control circuit
DAs a constant voltage reference in a power supply

27. - E6C07

What best describes a pull-up or pull-down resistor?

SelectAnswer
AA resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
BA resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
CA resistor that ensures that an oscillator frequency does not drift
DA resistor in a keying circuit used to reduce key clicks

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

SelectAnswer
AFerrite toroids generally have better temperature stability
BFerrite toroids are easier to use with surface mount technology
CFerrite toroids generally have lower initial permeability
DFerrite toroids generally require fewer turns to produce a given inductance value

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

SelectAnswer
ASilicon nitride
BGallium nitride
CSilicon dioxide
DSilicon

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

SelectAnswer
APhotons
BProtons
CElectrons
DHoles

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

SelectAnswer
AAn OR gate
BA flip-flop
CA multiplexer
DAn XOR gate

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

SelectAnswer
AAll these choices are correct
BSelect transistors with high beta
CUse a resistor in series with the emitter
DNeutralization

33. - E7C08

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

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

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

SelectAnswer
AMinimum input-to-output voltage required to maintain regulation
BMaximum that the output voltage may decrease at rated load
CMaximum output voltage drops when the input voltage is varied over its specified range
DMinimum input voltage for rated power dissipation

35. - E7E04

What is one way a single-sideband phone signal can be generated?

SelectAnswer
ABy using a reactance modulator followed by a mixer
BBy using a loop modulator followed by a mixer
CBy driving a product detector with a DSB signal
DBy using a balanced modulator followed by a filter

36. - E7F08

What is the function of decimation?

SelectAnswer
AReducing the effective sample rate by removing samples
BAttenuating the signal
CRemoving unnecessary significant digits
DConverting data to binary code decimal form

37. - E7G03

What is the typical input impedance of an op-amp?

SelectAnswer
AVery low
B1000 ohms
CVery high
D100 ohms

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

SelectAnswer
AUse a GPS signal reference
BUse a rubidium stabilized reference oscillator
CAll these choices are correct
DUse a temperature-controlled high Q dielectric resonator

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 sine wave
BA square wave
CA cosine wave
DA sawtooth wave

40. - E8B09

What is deviation ratio?

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

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

SelectAnswer
A13 Hz
B52 Hz
C104 Hz
D26 Hz

42. - E8D06

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

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

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

SelectAnswer
A2000 watts
B126 watts
C317 watts
D300 watts

44. - E9B02

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

SelectAnswer
A36 dB
B24 dB
C18 dB
D14 dB

45. - E9C10

Which of the following describes a Zepp antenna?

SelectAnswer
AA vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
BAn omni-directional antenna commonly used for satellite communications
CAn end-fed dipole antenna
DA dipole constructed from zip cord

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 unchanged if the loading coil is located at a voltage maximum point
DIt is increased

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

SelectAnswer
AIt allows single-band antennas to operate on other bands
BIt creates a low-angle radiation pattern
CIt prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
DIt ensures that each driven element operates in concert with the others to create the desired antenna pattern

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
B5.3 meters
C3.5 meters
D10.6 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

SelectAnswer
ADetermine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
BDetermine the length and position of an impedance matching stub
CDetermine the impedance of a transmission line, given the physical dimensions
DDetermine the gain of an antenna given the physical and electrical parameters

50. - E9H07

Why is RF attenuation used when direction-finding?

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

Figure E9-1