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

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
A1 kHz above the lower band edge
B3 kHz above the lower band edge
C300 Hz above the lower band edge
DThe exact lower band edge

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

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
BIARP agreement
CAll these choices are correct
DCEPT agreement

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

SelectAnswer
AThe output power of the balloon transmitter
BThe station's six-character Maidenhead grid locator
CCall sign
DAll these choices are correct

6. - E1E08

To which of the following examinees may a VE not administer an examination?

SelectAnswer
AFriends of the VE
BRelatives of the VE as listed in the FCC rules
CAll these choices are correct
DEmployees of the VE

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AAny licensed amateur operator
BOnly General, Advanced or Amateur Extra Class operators
COnly Technician, General, Advanced or Amateur Extra Class operators
DOnly Amateur Extra Class operators

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

SelectAnswer
ADoppler shift is reduced because the uplink and downlink shifts are in opposite directions
BAll these choices are correct
CUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa
DSignal position in the band is reversed

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

SelectAnswer
AA 440 MHz transceiver with a 9600 baud modem
BA 2 meter VHF transceiver with a 1200 baud modem
CA wireless router running custom firmware
DAn optical cable connection between the USB ports of 2 separate computers

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

SelectAnswer
AMSK144
BWSPR
CAPRS
DHellschreiber

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
APACTOR
BHellschreiber
CAMTOR
DRTTY

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
AFM
BCW
CRTTY
DSSB

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
AOnly 30 meters to 10 meters
B160 meters to 10 meters
C6 meters to 2 meters
DOnly 160 meters to 40 meters

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

SelectAnswer
ABy approximately 15 percent of the distance
BBy approximately twice the distance
CBy approximately four times the distance
DBy approximately 50 percent of the distance

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

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

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

SelectAnswer
A100 watts
B125 watts
C75 watts
D25 watts

18. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

SelectAnswer
AThe maximum count value of the analog-to-digital converter
BOne-half the maximum sampling buffer size
COne-half the maximum sample rate
DThe reference voltage of the analog-to-digital converter

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

SelectAnswer
AA band-pass filter in the feed line between the transmitter and receiver
BUtilizing a Class C final amplifier
CA properly terminated circulator at the output of the repeater's transmitter
DUtilizing a Class D final amplifier

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

SelectAnswer
ABy using a ground-fault current interrupter in the circuit used to power the motor
BBy installing a high-pass filter in series with the motor's power leads
CBy installing a brute-force AC-line filter in series with the motor leads
DBy installing a bypass capacitor in series with the motor leads

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
AConductance
BResistance
CCapacitance
DResonance

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

SelectAnswer
ATake the reciprocal of the magnitude and change the sign of the angle
BTake the square root of the magnitude and add 180 degrees to the angle
CTake the reciprocal of the angle and change the sign of the magnitude
DSquare the magnitude and subtract 90 degrees from the angle

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 8
BPoint 3
CPoint 1
DPoint 7

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

SelectAnswer
A1.73
B0.866
C0.5
D0.577

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
AP-type
BBipolar
CN-type
DInsulated gate

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

SelectAnswer
AReverse voltage larger than the RF signal
BA sub-harmonic pump signal
CCapacitance of an RF coupling capacitor
DForward DC bias current

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

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

28. - E6D13

What is the primary cause of inductor self-resonance?

SelectAnswer
AInter-turn capacitance
BNon-linear core hysteresis
CInductive kickback
DThe skin effect

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

SelectAnswer
AEpoxy coating is conductive above 300 MHz
BToo many pins
CExcessive lead length
DUnsuitable for combining analog and digital signals

30. - E6F04

What is the photovoltaic effect?

SelectAnswer
AThe conversion of voltage to current when exposed to light
BThe tendency of a battery to discharge when exposed to light
CThe conversion of electrical energy to mechanical energy
DThe conversion of light to electrical energy

31. - E7A06

What is a characteristic of a monostable multivibrator?

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

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

SelectAnswer
AIncreased overall intelligibility
BSignal inversion
CSignal distortion and excessive bandwidth
DReduced intermodulation products

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

SelectAnswer
AA Phase Inverter Load network
BA network with only three discrete parts
CA Pi-network with an additional series inductor on the output
DA matching network in which all components are isolated from ground

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

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

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

SelectAnswer
AThe two input frequencies along with their sum and difference frequencies
BThe square root of the product of input frequencies
CTwo and four times the original frequency
D1.414 and 0.707 times the input frequency

36. - E7F09

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

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

37. - E7G01

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

SelectAnswer
AVery high
B1000 ohms
C100 ohms
DVery low

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 direct digital synthesizer
CA phase-locked loop synthesizer
DA hybrid synthesizer

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. - E8B10

What is frequency division multiplexing?

SelectAnswer
ATwo or more information streams are merged into a baseband, which then modulates the transmitter
BThe transmitted signal jumps from band to band at a predetermined rate
CThe transmitted signal is divided into packets of information
DTwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C10

How may data rate be increased without increasing bandwidth?

SelectAnswer
AUsing forward error correction
BIt is impossible
CIncreasing analog-to-digital conversion resolution
DUsing a more efficient digital code

42. - E8D01

Why are received spread spectrum signals resistant to interference?

SelectAnswer
AThe high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
BIf interference is detected by the receiver it will signal the transmitter to change frequencies
CSignals not using the spread spectrum algorithm are suppressed in the receiver
DThe receiver is always equipped with a digital blanker

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

SelectAnswer
A63.2 watts
B252 watts
C159 watts
D632 watts

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

SelectAnswer
A7.5 degrees
B75 degrees
C25 degrees
D45 degrees

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

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

SelectAnswer
AAt a voltage node
BAs close to the transmitter as possible
CNear the center of the vertical radiator
DAs low as possible on the vertical radiator

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

SelectAnswer
AConnect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
BConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
CInsert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
DInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

SelectAnswer
AHigher SWR
BSmaller reflection coefficient
CLower loss
DLower velocity factor

49. - E9G02

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

SelectAnswer
AResistance lines and reactance chords
BVoltage lines and current chords
CVoltage circles and current arcs
DResistance circles and reactance arcs

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

SelectAnswer
AThey must be erected at least 1/2 wavelength above the ground to attain good directivity
BAtmospheric noise is so high that gain over a dipole is not important
CAll these choices are correct
DLow loss coax transmission line is essential for good performance

Figure E5-1

Figure E9-2