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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

SelectAnswer
AEnsure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
BEnsure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
CEnsure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
DEnsure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

SelectAnswer
ANone; they are allowed on all amateur frequencies
BThey are not permitted above 54 MHz
CThey are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
DThey are restricted to phone band segments

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

SelectAnswer
AThe amateur station must avoid transmitting during certain hours on frequencies that cause the interference
BThe amateur station must cease operation on all frequencies above 30 MHz
CThe amateur station must cease operation on all frequencies below 30 MHz
DThe amateur station must cease operation

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

SelectAnswer
AUnder automatic control there is no control operator
BUnder local control there is no control operator
CUnder automatic control the control operator is not required to be present at the control point
DUnder local control a control operator is not required to be present at a control point

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

6. - E1E12

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

SelectAnswer
AMaintain the application form with the VEC's records
BDestroy the application form
CSend the application form to the FCC and inform the FCC of the grade
DReturn the application document to the examinee

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 Amateur Extra Class operators
DOnly General, Advanced or Amateur Extra Class operators

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

SelectAnswer
ATo delay download of telemetry between satellites
BTo upload operational software for the transponder
CTo store digital messages in the satellite for later download by other stations
DTo relay messages between satellites

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

SelectAnswer
A30 meters
B33 centimeters
C2 meters
D6 meters

11. - E2D06

Which of the following describes a method of establishing EME contacts?

SelectAnswer
ATime synchronous transmissions alternately from each station
BJudging optimum transmission times by monitoring beacons reflected from the moon
CStoring and forwarding digital messages
DHigh-speed CW identification to avoid fading

12. - E2E02

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

SelectAnswer
AForward Error Correction
BFirst Error Correction
CFatal Error Correction
DFinal Error Correction

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

SelectAnswer
AWarm and cold fronts
BGrayline
CSprites and jets
DLightning discharges

14. - E3B10

Why is chordal hop propagation desirable?

SelectAnswer
AThe signal experiences less loss compared to multi-hop using Earth as a reflector
BSignals travel faster along ionospheric chords
CThe MUF for chordal hop propagation is much lower than for normal skip propagation
DAtmospheric noise is lower in the direction of chordal hop propagation

15. - E3C02

What is indicated by a rising A or K index?

SelectAnswer
AHigher levels of solar UV radiation
BIncreasing disruption of the geomagnetic field
CAn increase in the critical frequency
DDecreasing disruption of the geomagnetic field

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 analyzer via a high-impedance transformer to the antenna
CLoosely couple the analyzer near the antenna base
DConnect the antenna feed line directly to the analyzer's connector

17. - E4B05

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

SelectAnswer
AShort circuit, open circuit, and 50 ohms
BShort circuit, open circuit, and resonant circuit
C50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
D50 ohms, 75 ohms, and 90 ohms

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 intelligibility by using low Q circuitry to reduce ringing
DIt improves dynamic range by attenuating strong signals near the receive frequency

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

SelectAnswer
ASignals less than 40 dBm will not generate audible third-order intermodulation products
BA pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
CThe receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
DA pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal

20. - E4E10

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

SelectAnswer
AA defective doorbell or doorbell transformer inside a nearby residence
BAll these choices are correct
CA malfunctioning illuminated advertising display
DArcing contacts in a thermostatically controlled device

21. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

SelectAnswer
AMatching range is increased
BIt has no effect on impedance matching
CMatching bandwidth is increased
DMatching bandwidth is decreased

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
BCurrent leads voltage by 90 degrees
CVoltage leads current by 90 degrees
DVoltage and current are 180 degrees out of phase

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

SelectAnswer
AOmega
BDelta
C+jX
D-jX

24. - E5D11

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

SelectAnswer
A1.73
B1.414
C0.5
D0.866

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAn FET that exhibits a current flow between source and drain when no gate voltage is applied
BAny FET without a channel
CAny FET for which holes are the majority carriers
DAn FET that has no current flow between source and drain when no gate voltage is applied

26. - E6B01

What is the most useful characteristic of a Zener diode?

SelectAnswer
AA negative resistance region
BAn internal capacitance that varies with the applied voltage
CA constant current drop under conditions of varying voltage
DA constant voltage drop under conditions of varying current

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AIt has the high input impedance of CMOS and the low output impedance of bipolar transistors
BIt is immune to electrostatic damage
CAll these choices are correct
DIts simplicity results in much less expensive devices than standard CMOS

28. - E6D13

What is the primary cause of inductor self-resonance?

SelectAnswer
ANon-linear core hysteresis
BThe skin effect
CInductive kickback
DInter-turn capacitance

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

SelectAnswer
A2 dB
B44 dBm
C-20 dBm
D-10 dB

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. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt stores one bit of data in either a 0 or 1 state
BIt maintains a constant output voltage, regardless of variations in the input voltage
CIt switches momentarily to the opposite binary state and then returns to its original state after a set time
DIt produces a continuous square wave oscillating between 1 and 0

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

SelectAnswer
AA differential amplifier with both inputs fed to the emitter of the input transistor
BAn OR circuit with only one emitter used for output
CAn amplifier with a low impedance output that follows the base input voltage
DA two-transistor amplifier with the emitters sharing a common bias resistor

33. - E7C08

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

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

34. - E7D05

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

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

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

SelectAnswer
AA heterodyne suppressor
BA de-emphasis network
CA heterodyne enhancer
DA pre-emphasis network

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

SelectAnswer
AFIR filters are easier to implement for a given set of passband rolloff requirements
BFIR filters can respond faster to impulses
CFIR filters can delay all frequency components of the signal by the same amount
DAll these choices are correct

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 output voltage of the op-amp minus its input voltage
CThe potential between the amplifier input terminals of the op-amp in an open loop condition
DThe difference between the output voltage of the op-amp and the input voltage required in the immediately following stage

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
ATaft, Pierce and negative feedback
BPierce, Fenner and Beane
CColpitts, Hartley and Pierce
DTaft, Hartley and Pierce

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

SelectAnswer
AAll these choices are correct
BImmunity to out-of-sequence coding reduces spurious responses
CVery low power consumption decreases frequency drift
DVery high speed allows digitizing high frequencies

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

SelectAnswer
AExtremely low-power contacts
BOFDM signals are not allowed on amateur bands
CHigh-speed digital modes
DEME

41. - E8C02

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

SelectAnswer
AThe number of characters carried per second by the station-to-station link
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 control characters in a message packet

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

SelectAnswer
AExcessive numbers of retries
BBit errors in the modem
CGround loops
DExcessive transmit audio levels

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
A317 watts
B300 watts
C126 watts
D2000 watts

44. - E9B02

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

SelectAnswer
A14 dB
B36 dB
C24 dB
D18 dB

45. - E9C08

What is a folded dipole antenna?

SelectAnswer
AA dipole one-quarter wavelength long
BA type of ground-plane antenna
CA half-wave dipole with an additional parallel wire connecting its two ends
DA dipole configured to provide forward gain

46. - E9D11

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

SelectAnswer
ASolid wire
BResistive wire, such as spark plug wire
CStranded wire
DWide flat copper strap

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

SelectAnswer
ATo provide DC isolation between the feed line and the antenna
BTo cancel the inductive reactance of the matching network
CTo provide a rejection notch that prevents the radiation of harmonics
DTo transform the antenna impedance to a higher value

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

SelectAnswer
AAll these choices are correct
BFoam dielectric has lower loss per unit of length
CFoam dielectric has higher velocity factor
DFoam dielectric has lower safe operating voltage limits

49. - E9G01

Which of the following can be calculated using a Smith chart?

SelectAnswer
ARadio propagation
BAntenna radiation pattern
CRadiation resistance
DImpedance along transmission lines

50. - E9H04

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

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

Figure E9-1