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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

SelectAnswer
ALightning protection
BReduce RF current flow between pieces of equipment
CReduce received noise
DReduce RFI to telephones and home entertainment systems

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

SelectAnswer
AThe amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
BThe amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
CIts operation must be approved by the master of the ship or the pilot in command of the aircraft
DThe amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AState and local zoning
BFAA tower height limits
CUse of wireless devices in vehicles
DHomeowners associations

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
AITU reciprocal license
BCEPT agreement
CIARP agreement
DAll these choices are correct

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A33 cm and 13 cm
B70 cm only
C70 cm and 33 cm
D70 cm and 13 cm

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

SelectAnswer
AWarn the candidate that continued failure to comply will result in termination of the examination
BAllow the candidate to complete the examination, but invalidate the results
CImmediately terminate everyone's examination and close the session
DImmediately terminate the candidate's examination

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

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

SelectAnswer
ATo avoid interfering with terrestrial QSOs
BTo prevent the satellite from emitting out-of-band signals
CTo avoid reducing the downlink power to all other users
DTo prevent creating errors in the satellite telemetry

9. - E2B06

What is vestigial sideband modulation?

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

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

SelectAnswer
A/ followed by the ARRL Section of the remote station
B/R# where # is the district of the remote station
C/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
DNo additional indicator is required

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
BUse of special digital modes
CAll these choices are correct
DShort transmissions with rapidly repeated call signs and signal reports

12. - E2E06

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

SelectAnswer
A48 baud
B1200 baud
C300 baud
D110 baud

13. - E3A12

What is the cause of auroral activity?

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

14. - E3B12

What is the primary characteristic of chordal hop propagation?

SelectAnswer
ASuccessive ionospheric refractions without an intermediate reflection from the ground
BSignals reflected back toward the transmitting station
CPropagation away from the great circle bearing between stations
DPropagation across the geomagnetic equator

15. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the sun will cause disturbed conditions?

SelectAnswer
ANorthward
BEastward
CSouthward
DWestward

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

SelectAnswer
AA square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible
BA frequency standard is displayed and the probe is adjusted until the deflection time is accurate
CA DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
DA high frequency sine wave is displayed and the probe is adjusted for maximum amplitude

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

SelectAnswer
ADecade divider accuracy
BInput attenuator accuracy
CTemperature coefficient of the logic
DTime base accuracy

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

SelectAnswer
A-148 dBm
B-164 dBm
C-174 dBm
D-155 dBm

19. - E4D03

How can intermodulation interference between two repeaters occur?

SelectAnswer
AWhen the signals from the transmitters are reflected in phase from airplanes passing overhead
BWhen the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
CWhen the signals from the transmitters are reflected out of phase from airplanes passing overhead
DWhen the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

SelectAnswer
ARemoval of the CW signal as well as the interfering carrier
BAny nearby signal passing through the DSP system will overwhelm the desired signal
CReceived CW signals will appear to be modulated at the DSP clock frequency
DRinging in the DSP filter will completely remove the spaces between the CW characters

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

SelectAnswer
AIt is at a maximum
BIt is at a minimum
CIt equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
DIt equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C

22. - E5B04

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

SelectAnswer
A55 seconds
B440 seconds
C220 seconds
D110 seconds

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

SelectAnswer
AMaidenhead grid
BElliptical coordinates
CFaraday grid
DRectangular coordinates

24. - E5D14

What is reactive power?

SelectAnswer
APower lost because of capacitor leakage
BPower consumed in wire resistance in an inductor
CPower consumed in circuit Q
DWattless, nonproductive power

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
AThey are both high impedance
BAn FET has higher input impedance
CThey are both low impedance
DAn FET has lower input impedance

26. - E6B05

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

SelectAnswer
AAbility to dissipate large amounts of power
BReverse bias controls its forward voltage drop
CLow junction capacitance
DExtremely high reverse breakdown voltage

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AIts simplicity results in much less expensive devices than standard CMOS
BAll these choices are correct
CIt is immune to electrostatic damage
DIt has the high input impedance of CMOS and the low output impedance of bipolar transistors

28. - E6D08

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

SelectAnswer
APowdered-iron cores use smaller diameter wire for the same inductance
BPowdered-iron cores generally maintain their characteristics at higher currents
CPowdered-iron cores generally have greater initial permeability
DPowdered-iron cores generally require fewer turns to produce a given inductance

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

SelectAnswer
AHigher electron mobility
BHigher noise figures
CLower junction voltage drop
DLower transconductance

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt stays the same
BIt increases
CIt decreases
DIt becomes unstable

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

SelectAnswer
AIt produces logic 0 at its output if only one input is logic 1
BIt produces logic 1 at its output if only one input is logic 1
CIt produces logic 1 at its output only if all inputs are logic 1
DIt produces logic 0 at its output only if all inputs are logic 0

32. - E7B08

How can an RF power amplifier be neutralized?

SelectAnswer
ABy increasing the driving power
BBy reducing the driving power
CBy feeding an in-phase component of the output back to the input
DBy feeding a 180-degree out-of-phase portion of the output back to the input

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

SelectAnswer
AIt cancels the reactive part of the impedance and changes the resistive part to a desired value
BReactive currents are dissipated in matched resistances
CIt introduces negative resistance to cancel the resistive part of impedance
DIt introduces transconductance to cancel the reactive part of impedance

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. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

SelectAnswer
AFor compatibility with transmitters using phase modulation
BFor higher efficiency
CTo remove third-order distortion products
DTo reduce impulse noise reception

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

SelectAnswer
AAt four times the rate of the highest frequency component of the signal
BAt the same rate as the highest frequency component of the signal
CAt least half the rate of the highest frequency component of the signal
DAt least twice the rate of the highest frequency component of the signal

37. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 3300 ohms and RF is 47 kilohms?

SelectAnswer
A7
B0.07
C14
D28

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

SelectAnswer
AA diode-switching matrix synthesizer
BA phase-locked loop synthesizer
CA hybrid synthesizer
DA direct digital synthesizer

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

SelectAnswer
AA small amount of noise added to the input signal to allow more precise representation of a signal over time
BAn abnormal condition where the converter cannot settle on a value to represent the signal
CAn error caused by irregular quantization step size
DA method of decimation by randomly skipping samples

40. - E8B07

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

SelectAnswer
AEME
BExtremely low-power contacts
CHigh-speed digital modes
DOFDM signals are not allowed on amateur bands

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
ABaud is twice the symbol rate
BSymbol rate is only used for packet-based modes
CBaud is only used for RTTY
DThey are the same

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

SelectAnswer
AExcessive transmit audio levels
BGround loops
CExcessive numbers of retries
DBit errors in the modem

43. - E9A08

What is antenna bandwidth?

SelectAnswer
AThe frequency range over which an antenna satisfies a performance requirement
BThe angle formed between two imaginary lines drawn through the element ends
CAntenna length divided by the number of elements
DThe angle between the half-power radiation points

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

SelectAnswer
AThe computed feed point impedance may be incorrect
BThe antenna will become mechanically unstable
CThe resulting design will favor radiation of harmonic energy
DGround conductivity will not be accurately modeled

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

SelectAnswer
AIt changes the radiation pattern from bidirectional to unidirectional
BIt decreases the ground loss
CIt reflects the standing waves on the antenna elements back to the transmitter
DIt changes the radiation pattern from horizontal to vertical polarization

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

SelectAnswer
ATo swamp out harmonics
BTo lower the radiation angle
CTo minimize the Q
DTo minimize losses

47. - E9E04

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

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

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
B7.0 meters
C13.3 meters
D10.6 meters

49. - E9G01

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

SelectAnswer
ARadiation resistance
BRadio propagation
CImpedance along transmission lines
DAntenna radiation pattern

50. - E9H06

What is the triangulation method of direction finding?

SelectAnswer
AThe geometric angles of sky waves from the source are used to determine its position
BAntenna headings from several different receiving locations are used to locate the signal source
CA fixed receiving station uses three different antennas to plot the location of the signal source
DA fixed receiving station plots three headings to the signal source