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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 are ionizing radiation
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 often travel long distances by ionospheric reflection

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
A300 Hz above the lower band edge
B1 kHz above the lower band edge
C3 kHz above the lower band edge
DThe exact lower band edge

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

SelectAnswer
AYou must file an Environmental Impact Statement with the EPA before construction begins
BYou must obtain a construction permit from the airport zoning authority
CYou may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
DYou must submit engineering drawings to the FAA

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

SelectAnswer
A5 minutes
B10 minutes
C30 seconds
D3 minutes

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A70 cm and 33 cm
B33 cm and 13 cm
C70 cm only
D70 cm and 13 cm

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

SelectAnswer
APreparing, processing, administering, and coordinating an examination for an amateur radio operator license
BProviding amateur operator license examination preparation training materials
CTeaching an amateur operator license examination preparation course
DNo expenses are authorized for reimbursement

7. - E1F04

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

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

8. - E2A12

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

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

9. - E2B01

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

SelectAnswer
A60
B30
C90
D120

10. - E2C07

What is the Cabrillo format?

SelectAnswer
AThe most common set of contest rules
BA standard for submission of electronic contest logs
CThe rules of order for meetings between contest sponsors
DA method of exchanging information during a contest QSO

11. - E2D03

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

SelectAnswer
APACTOR III
BOlivia
CMSK144
DJT65

12. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

SelectAnswer
AOne of the signal filters is saturated
BThe mark and space signal have been inverted
CThe receiver has drifted 5 kHz from the desired receive frequency
DSelective fading has occurred

13. - E3A12

What is the cause of auroral activity?

SelectAnswer
AThe interaction in the F2 layer between the solar wind and the Van Allen belt
BAn extreme low-pressure area in the polar regions
CMeteor showers concentrated in the extreme northern and southern latitudes
DThe interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

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 elliptically polarized
DThey become depolarized

15. - E3C08

What does the space weather term G5 mean?

SelectAnswer
AModerate solar wind
BAn extreme geomagnetic storm
CVery low solar activity
DWaning sunspot numbers

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

SelectAnswer
AAll these choices are correct
BNever use a high-impedance probe to measure a low-impedance circuit
CNever use a DC-coupled probe to measure an AC circuit
DKeep the signal ground connection of the probe as short as possible

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

SelectAnswer
AModulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
BModulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
CModulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
DModulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

SelectAnswer
AEasier for front-end circuitry to eliminate image responses
BReduced drift
CImproved receiver noise figure
DFewer components in the receiver

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

SelectAnswer
AIntermodulation
BAmplifier desensitization
CNeutralization
DAdjacent channel interference

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

SelectAnswer
ACommon-mode currents on the shield and conductors
BUse of braided shielding material
CTying all ground connections to a common point resulting in differential-mode currents in the shield
DLow inductance ground connections at both ends of the shield

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

SelectAnswer
ACapacitance
BResonance
CResistance
DConductance

22. - E5B02

What letter is commonly used to represent susceptance?

SelectAnswer
AY
BG
CX
DB

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

SelectAnswer
APoint 4
BPoint 2
CPoint 5
DPoint 6

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

SelectAnswer
A0.707
B0.866
C1.0
D0.5

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

SelectAnswer
A6
B1
C2
D3

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

SelectAnswer
AReverse bias controls its forward voltage drop
BAbility to dissipate large amounts of power
CExtremely high reverse breakdown voltage
DLow junction capacitance

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

SelectAnswer
AToroidal cores confine most of the magnetic field within the core material
BToroidal cores make it easier to couple the magnetic energy into other components
CToroidal cores have lower Q characteristics
DToroidal cores exhibit greater hysteresis

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

SelectAnswer
ATwo chips in each package (Dual In Package)
BLow leakage doubly insulated package
CA total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
DPackage mounts in a direct inverted position

30. - E6F05

Which describes an optical shaft encoder?

SelectAnswer
AA digital encryption device often used to encrypt spacecraft control signals
BA device that measures the strength of a beam of light using analog to digital conversion
CA device for generating RTTY signals by means of a rotating light source
DA device that detects rotation of a control by interrupting a light source with a patterned wheel

31. - E7A01

Which circuit is bistable?

SelectAnswer
AA flip-flop
BA bipolar amplifier
CAn AND gate
DAn OR gate

32. - E7B02

What is a Class D amplifier?

SelectAnswer
AA type of amplifier that uses switching technology to achieve high efficiency
BA low power amplifier that uses a differential amplifier for improved linearity
CAn amplifier that uses drift-mode FETs for high efficiency
DA frequency doubling amplifier

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

SelectAnswer
AA DSP filter
BA crystal filter
CA cavity filter
DAn L-C filter

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

SelectAnswer
AIt uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
BThe high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
CIt uses a diode bridge rectifier for increased output
DThe inverter design does not require any output filtering

35. - E7E05

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

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

36. - E7F07

What function is performed by a Fast Fourier Transform?

SelectAnswer
AConverting digital signals from the time domain to the frequency domain
BConverting analog signals to digital form
CConverting 8-bit data to 16-bit data
DConverting digital signals to analog form

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

SelectAnswer
AThe gain of the amplifier at a filter's cutoff frequency
BThe frequency at which the amplifier's offset voltage is zero
CThe maximum frequency for a filter circuit using that type of amplifier
DThe frequency at which the open-loop gain of the amplifier equals one

38. - E7H14

What is a phase-locked loop circuit?

SelectAnswer
AAn electronic circuit also known as a monostable multivibrator
BAn electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
CAn electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
DAn electronic circuit consisting of a precision push-pull amplifier with a differential input

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

SelectAnswer
ARemove harmonics from the output caused by the discrete analog levels generated
BLower the input bandwidth to increase the effective resolution
CAll these choices are correct
DImprove accuracy by removing out-of-sequence codes from the input

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

SelectAnswer
A0.167
B60
C1.67
D0.6

41. - E8C01

How is Forward Error Correction implemented?

SelectAnswer
ABy transmitting extra data that may be used to detect and correct transmission errors
BBy the receiving station repeating each block of three data characters
CBy varying the frequency shift of the transmitted signal according to a predefined algorithm
DBy transmitting a special algorithm to the receiving station along with the data characters

42. - E8D05

What is the most common method of reducing key clicks?

SelectAnswer
ALow-pass filters at the transmitter output
BIncrease keying waveform rise and fall times
CHigh-pass filters at the transmitter output
DReduce keying waveform rise and fall times

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
B126 watts
C300 watts
D2000 watts

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

SelectAnswer
A38 dB
B15 dB
C28 dB
D3 dB

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 increases
BThe low-angle radiation decreases
CAdditional higher vertical angle lobes will appear
DFewer vertical angle lobes will be present

46. - E9D12

Which of the following would provide the best RF ground for your station?

SelectAnswer
AAn electrically short connection to a metal water pipe
BA 50-ohm resistor connected to ground
CAn electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
DAn electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

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
A50 ohms
B62 ohms
C75 ohms
D450 ohms

48. - E9F01

What is the velocity factor of a transmission line?

SelectAnswer
AThe velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
BThe ratio of the characteristic impedance of the line to the terminating impedance
CThe velocity of the wave in the transmission line divided by the velocity of light in a vacuum
DThe index of shielding for coaxial cable

49. - E9G02

What type of coordinate system is used in a Smith chart?

SelectAnswer
AResistance lines and reactance chords
BResistance circles and reactance arcs
CVoltage circles and current arcs
DVoltage lines and current chords

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

SelectAnswer
AA very sharp peak
BBroadband response
CHigh radiation angle
DA very sharp single null