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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A30 to 300 MHz
B3 to 30 MHz
C300 kHz to 3 MHz
D300 to 3000 MHz

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

SelectAnswer
A3 kHz above the lower band edge
B1 kHz above the lower band edge
C300 Hz above the lower band edge
DThe exact lower band edge

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

SelectAnswer
AAll these choices are correct
BFile an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
CCease operation or make changes to the repeater to mitigate the interference
DReduce the repeater antenna HAAT (Height Above Average Terrain)

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

SelectAnswer
AOperators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
BOperators must not operate until approval is received
COperators may not operate until a test signal has been transmitted in coordination with the local power company
DOperations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

SelectAnswer
AAll HF bands
BOnly the 40, 30, 20, 15, 12, and 10 meter bands
COnly the 40, 20, 17, 15, 12, and 10 meter bands
DOnly the 40, 20, 17, 15, and 10 meter bands

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. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

SelectAnswer
AA line roughly parallel to and west of the U.S. Atlantic coastline
BA line roughly parallel to and north of the border between the U.S. and Mexico
CA line roughly parallel to and east of the U.S. Pacific coastline
DA line roughly parallel to and south of the border between the U.S. and Canada

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

SelectAnswer
AFrom east to west
BFrom west to east
CFrom north to south
DFrom south to north

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

SelectAnswer
A90
B60
C120
D30

10. - E2C03

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

SelectAnswer
A33 centimeters
B6 meters
C30 meters
D2 meters

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

SelectAnswer
A15-second timed transmission sequences with stations alternating based on location
BShort transmissions with rapidly repeated call signs and signal reports
CAll these choices are correct
DUse of special digital modes

12. - E2E02

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

SelectAnswer
AFinal Error Correction
BFatal Error Correction
CForward Error Correction
DFirst Error Correction

13. - E3A04

What do Hepburn maps predict?

SelectAnswer
ALikelihood of rain scatter along cold or warm fronts
BSporadic E propagation
CLocations of auroral reflecting zones
DProbability of tropospheric propagation

14. - E3B03

What is the best time of day for transequatorial propagation?

SelectAnswer
ANoon
BMorning
CLate at night
DAfternoon or early evening

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. - E4A05

What is the purpose of the prescaler function on a frequency counter?

SelectAnswer
AIt prevents oscillation in a low-frequency counter circuit
BIt divides a higher frequency signal so a low-frequency counter can display the input frequency
CIt multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
DIt amplifies low-level signals for more accurate counting

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

SelectAnswer
AS22
BS21
CS12
DS11

18. - E4C10

What is an advantage of having a variety of receiver IF bandwidths from which to select?

SelectAnswer
AReceive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference
BMultiple frequencies can be received simultaneously if desired
CThe noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity
DReceiver power consumption can be reduced when wider bandwidth is not required

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

SelectAnswer
AThe difference in dB between the noise floor and the third-order intercept point
BThe minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
CThe minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
DThe difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression

20. - E4E08

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

SelectAnswer
AReactive current only
BCommon-mode current
CDifferential-mode current
DReturn current

21. - E5A05

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

SelectAnswer
AMatching range is increased
BMatching bandwidth is increased
CIt has no effect on impedance matching
DMatching bandwidth is decreased

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

SelectAnswer
A220 seconds
B440 seconds
C55 seconds
D110 seconds

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

SelectAnswer
APoint 7
BPoint 1
CPoint 3
DPoint 8

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

SelectAnswer
A252 W
B355 W
C704 W
D1.42 mW

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAny FET for which holes are the majority carriers
BAny FET without a channel
CAn FET that has no current flow between source and drain when no gate voltage is applied
DAn FET that exhibits a 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
BA constant voltage drop under conditions of varying current
CA constant current drop under conditions of varying voltage
DAn internal capacitance that varies with the applied voltage

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

SelectAnswer
ALower power consumption
BLower distortion
CDifferential output capability
DImmune to damage from static discharge

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

SelectAnswer
ABrass
BCeramic
CFerrite
DPowdered iron

29. - E6E07

What type of transmission line is used for connections to MMICs?

SelectAnswer
AParallel wire
BMicrostrip
CMiniature coax
DCircular waveguide

30. - E6F09

What is the efficiency of a photovoltaic cell?

SelectAnswer
AThe open-circuit voltage divided by the short-circuit current under full illumination
BThe output RF power divided by the input DC power
CCost per kilowatt-hour generated
DThe relative fraction of light that is converted to current

31. - E7A03

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

SelectAnswer
AA multiplexer
BAn OR gate
CA flip-flop
DAn XOR gate

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

SelectAnswer
AClass AB
BClass C
CPush-pull
DPush-push

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

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

SelectAnswer
ADischarge the capacitors when voltage is removed
BProvide a minimum load on the supply
CEqualize the voltage across each capacitor
DAll these choices are correct

35. - E7E02

What is the function of a reactance modulator?

SelectAnswer
ATo produce PM or FM signals by using an electrically variable inductance or capacitance
BTo produce AM signals by using an electrically variable resistance
CTo produce PM signals by using an electrically variable resistance
DTo produce AM signals by using an electrically variable inductance or capacitance

36. - E7F09

Why is an anti-aliasing digital filter required in a digital decimator?

SelectAnswer
AIt peaks the response of the decimator, improving bandwidth
BIt removes high-frequency signal components that would otherwise be reproduced as lower frequency components
CIt removes low-frequency signal components to eliminate the need for DC restoration
DIt notches out the sampling frequency to avoid sampling errors

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

SelectAnswer
A24
B94
C47
D0.21

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

SelectAnswer
AFrequency synthesis, FM demodulation
BComparison of two digital input signals, digital pulse counter
CPhotovoltaic conversion, optical coupling
DWide-band AF and RF power amplification

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

SelectAnswer
ASpeech characteristics
BThe frequency of the modulating signal
CThe degree of carrier suppression
DAmplifier gain

40. - E8B01

What is the modulation index of an FM signal?

SelectAnswer
AThe ratio of frequency deviation to modulating signal frequency
BThe bandwidth of the transmitted signal divided by the modulating signal frequency
CThe ratio of modulating signal amplitude to frequency deviation
DThe type of modulation used by the transmitter

41. - E8C07

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

SelectAnswer
A5.76 kHz
B15.36 kHz
C9.6 kHz
D4.8 kHz

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

SelectAnswer
AIf interference is detected by the receiver it will signal the transmitter to change frequencies
BA binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
CThe frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station
DIf interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear

43. - E9A04

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

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

44. - E9B08

What is the far field of an antenna?

SelectAnswer
AThe region where radiated power dissipates over a specified time period
BThe region where the shape of the antenna pattern is independent of distance
CThe region of the ionosphere where radiated power is not refracted
DThe region where radiated field strengths are constant

45. - E9C02

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

SelectAnswer
AOmni-directional
BA figure-8 end-fire along the axis of the array
CCardioid
DA figure-8 broadside to the axis of the array

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 unchanged if the loading coil is located at the feed point
BIt is decreased
CIt is increased
DIt is unchanged if the loading coil is located at a voltage maximum point

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

SelectAnswer
AThe delta match
BThe gamma match
CThe stub match
DThe omega match

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
A7.0 meters
B10.6 meters
C13.3 meters
D8.5 meters

49. - E9G10

What do the arcs on a Smith chart represent?

SelectAnswer
APoints with constant reactance
BPoints with constant resistance
CSWR
DFrequency

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
AForward gain compared to the gain in the reverse direction
BRelative directivity compared to isotropic
CRelative directivity compared to a dipole
DForward gain compared to average gain over the entire hemisphere

Figure E5-1