Anonymous User

Hamboozler

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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

SelectAnswer
AMicrowaves are ionizing radiation
BMicrowaves often travel long distances by ionospheric reflection
CThe extremely high frequency energy can damage the joints of antenna structures
DThe high gain antennas commonly used can result in high exposure levels

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

SelectAnswer
A50 watts PEP effective radiated power relative to a dipole
B50 watts PEP effective radiated power relative to an isotropic radiator
C100 watts PEP effective radiated power relative to an isotropic radiator
D100 watts PEP effective radiated power relative to the gain of a half-wave dipole

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

SelectAnswer
AA proposal must be submitted to the National Park Service
BAn Environmental Assessment must be submitted to the FCC
CA form FSD-15 must be submitted to the Department of the Interior
DA letter of intent must be filed with the Environmental Protection Agency

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

SelectAnswer
A1.5 kHz
B60 Hz
C2.8 kHz
D170 Hz

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
BCall sign
CAll these choices are correct
DThe station's six-character Maidenhead grid locator

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

SelectAnswer
AThe VE session manager
BThe FCC
CEach administering VE
DThe VEC coordinating the session

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. - E2A06

What are Keplerian elements?

SelectAnswer
AParameters that define the orbit of a satellite
BEncrypting codes used for spread spectrum modulation
CPhase reversing elements in a Yagi antenna
DHigh-emission heater filaments used in magnetron tubes

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
CAmplitude modulation in which one complete sideband and a portion of the other are transmitted
DA type of modulation in which one sideband is inverted

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

SelectAnswer
AThe acceptable practice of manually posting the call signs of stations on a spotting network
BA manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
CThe often-prohibited practice of posting one's own call sign and frequency on a spotting network
DAn automatic method for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D04

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

SelectAnswer
AAPRS
BDoppler shift of beacon signals
CBandwidth compressed LORAN
DUltrasonics

12. - E2E12

How do ALE stations establish contact?

SelectAnswer
AALE radios monitor an internet site for the frequency they are being paged on
BALE radios send a constant tone code to establish a frequency for future use
CALE radios activate when they hear their signal echoed by back scatter
DALE constantly scans a list of frequencies, activating the radio when the designated call sign is received

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

SelectAnswer
ASwitch to a higher frequency HF band
BWait 90 minutes or so for the signal degradation to pass
CWait 24 hours before attempting another communication on the band
DSwitch to a lower frequency HF band

14. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

SelectAnswer
A1000 miles
B2500 miles
C7500 miles
D5000 miles

15. - E3C10

What does the 304A solar parameter measure?

SelectAnswer
AThe solar emission at 304 GHz, correlated to x-ray flare levels
BUV emissions at 304 angstroms, correlated to the solar flux index
CThe ratio of x-ray flux to radio flux, correlated to sunspot number
DThe solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

SelectAnswer
AQ of the circuit
BSampling rate of the analog-to-digital converter
CAll these choices are correct
DAmount of memory

17. - E4B05

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

SelectAnswer
A50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
BShort circuit, open circuit, and 50 ohms
C50 ohms, 75 ohms, and 90 ohms
DShort circuit, open circuit, and resonant circuit

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

SelectAnswer
AIt improves intelligibility by using low Q circuitry to reduce ringing
BIt improves sensitivity by reducing front end noise
CAll these choices are correct
DIt improves dynamic range by attenuating strong signals near the receive frequency

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

SelectAnswer
AQuieting
BCross-modulation interference
CDesensitization
DSquelch gain rollback

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

SelectAnswer
AFM signals can no longer be demodulated
BNearby signals may appear to be excessively wide even if they meet emission standards
CThe audio frequency bandwidth of the received signal might be compressed
DReceived audio in the speech range might have an echo effect

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
AResonance
BCapacitance
CConductance
DResistance

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. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

SelectAnswer
ANear field diagram
BFar field diagram
CVenn diagram
DPhasor diagram

24. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

SelectAnswer
AIn a circle around the conductor
BIn a direction opposite to the current
CIn the same direction as the current
DIn all directions; omni-directional

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

SelectAnswer
AN-type impurity
BAcceptor impurity
CDonor impurity
DInsulator impurity

26. - E6B09

What is a common use for point-contact diodes?

SelectAnswer
AAs an RF detector
BAs a high-voltage rectifier
CAs a constant voltage source
DAs a constant current source

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

SelectAnswer
A5
B2
C6
D4

28. - E6D11

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

SelectAnswer
AFerrite
BBrass
CPowdered iron
DCeramic

29. - E6E05

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

SelectAnswer
A-20 dBm
B44 dBm
C2 dB
D-10 dB

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

SelectAnswer
AUse a phase inverter in the output filter
BTune the stage for maximum SWR
CTune both the input and output for maximum power
DInstall parasitic suppressors and/or neutralize the stage

33. - E7C10

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

SelectAnswer
AA crystal filter
BAn L-C filter
CA DSP filter
DA cavity filter

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

SelectAnswer
ATo provide a dual-voltage output for reduced power applications
BTo allow for remote control of the power supply
CTo compensate for variations of the incoming line voltage
DTo allow the filter capacitors to charge gradually

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 suppressor
DA heterodyne enhancer

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

37. - E7G02

What is ringing in a filter?

SelectAnswer
APartial cancellation of the signal over a range of frequencies
BUndesired oscillations added to the desired signal
CAn echo caused by a long time delay
DA reduction in high frequency response

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

SelectAnswer
AWirewound resistors
BToroidal inductors
CNP0 capacitors
DNon-inductive resistors

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

SelectAnswer
AFourier analysis
BDifferential analysis
CVector analysis
DNumerical analysis

40. - E8B09

What is deviation ratio?

SelectAnswer
AThe ratio of the highest audio modulating frequency to the average audio modulating frequency
BThe ratio of the carrier center frequency to the audio modulating frequency
CThe ratio of the audio modulating frequency to the center carrier frequency
DThe ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

41. - E8C11

What is the relationship between symbol rate and baud?

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

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

SelectAnswer
A-30 dB
B+15 dB
C+10 dB
D-20 dB

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. - E9B11

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

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

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
BAdditional higher vertical angle lobes will appear
CFewer vertical angle lobes will be present
DThe low-angle radiation increases

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 increased
BIt is unchanged if the loading coil is located at a voltage maximum point
CIt is decreased
DIt is unchanged if the loading coil is located at the feed 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 gamma match
BThe delta match
CThe omega match
DThe stub 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
A8.5 meters
B7.0 meters
C13.3 meters
D10.6 meters

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

SelectAnswer
AResistance and reactance
BVoltage and impedance
CReactance and voltage
DResistance and voltage

50. - E9H08

What is the function of a sense antenna?

SelectAnswer
AIt allows DF antennas to receive signals at different vertical angles
BIt increases the sensitivity of a DF antenna array
CIt modifies the pattern of a DF antenna array to provide a null in one direction
DIt provides diversity reception that cancels multipath signals

Figure E6-3