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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

SelectAnswer
ABeryllium Oxide
BZinc oxide
CUranium Hexafluoride
DMica

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

SelectAnswer
ANotify the originating station that the communication does not comply with FCC rules
BDiscontinue forwarding the communication as soon as you become aware of it
CAll these choices are correct
DNotify the nearest FCC Field Engineers office

3. - E1B01

Which of the following constitutes a spurious emission?

SelectAnswer
AAn amateur station transmission made without the proper call sign identification
BAny transmitted signal that unintentionally interferes with another licensed radio station
CAn emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
DA signal transmitted to prevent its detection by any station other than the intended recipient

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
AIARP agreement
BAll these choices are correct
CCEPT agreement
DITU reciprocal license

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

SelectAnswer
AAny amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
BOnly those of General, Advanced or Amateur Extra Class operators
CAny amateur station, subject to the privileges of the class of operator license held by the control operator
DOnly those of Amateur Extra Class operators

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

SelectAnswer
AThey must collect and send the documents to the NCVEC for grading
BThey must collect and send the documents to the FCC according to instructions
CThey must collect and submit the documents to the coordinating VEC for grading
DThey must submit the application document to the coordinating VEC according to the coordinating VEC instructions

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

SelectAnswer
ATo allow regular operation on Land Mobile channels
BTo provide temporary operation while awaiting normal licensing
CTo provide additional spectrum for personal use
DTo provide for experimental amateur communications

8. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

SelectAnswer
ASSB and SSTV
BAll these choices are correct
CFM and CW
DPSK and packet

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

SelectAnswer
AContacts between a U.S. station and a non-U.S. station
BRepeater contacts between U.S. club members
CContacts using tactical call signs
DSpecial event contacts between stations in the U.S.

11. - E2D05

What is one advantage of the JT65 mode?

SelectAnswer
AThe ability to decode signals which have a very low signal-to-noise ratio
BPermits fast-scan TV transmissions over narrow bandwidth
CUses only a 65 Hz bandwidth
DEasily copied by ear if necessary

12. - E2E06

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

SelectAnswer
A110 baud
B300 baud
C48 baud
D1200 baud

13. - E3A02

What characterizes libration fading of an EME signal?

SelectAnswer
AThe returning echo is several hertz lower in frequency than the transmitted signal
BA gradual loss of signal as the sun rises
CA fluttery irregular fading
DA slow change in the pitch of the CW signal

14. - E3B10

Why is chordal hop propagation desirable?

SelectAnswer
AAtmospheric noise is lower in the direction of chordal hop propagation
BSignals travel faster along ionospheric chords
CThe signal experiences less loss compared to multi-hop using Earth as a reflector
DThe MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

SelectAnswer
AA temperature inversion has occurred
BLong-path propagation is likely
CIncreased transequatorial propagation is likely
DA solar flare has occurred

16. - E4A08

Which of the following measures SWR?

SelectAnswer
AA spectrum analyzer
BAn antenna analyzer
CA Q meter
DAn ohmmeter

17. - E4B03

Which S parameter is equivalent to forward gain?

SelectAnswer
AS22
BS11
CS12
DS21

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

SelectAnswer
AIt can combine with strong signals on nearby frequencies to generate interference
BIt limits the receiver's ability to receive strong signals
CIt decreases receiver third-order intercept point
DIt can affect the receiver's frequency calibration

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
AAdjacent channel interference
BAmplifier desensitization
CNeutralization
DIntermodulation

20. - E4E09

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

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

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

SelectAnswer
AR/L
BMinimum
CMaximum
DL/R

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

SelectAnswer
AVoltage leads current by 90 degrees
BVoltage and current are 180 degrees out of phase
CCurrent leads voltage by 90 degrees
DVoltage and current are in phase

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

SelectAnswer
APoint 1
BPoint 8
CPoint 7
DPoint 3

24. - E5D15

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

SelectAnswer
A0.866
B1.0
C0.707
D0.5

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

SelectAnswer
ABase-to-emitter resistance of approximately 0.6 to 0.7 ohms
BBase-to-emitter resistance of approximately 6 to 7 ohms
CBase-to-emitter voltage of approximately 0.6 to 0.7 volts
DBase-to-emitter voltage of approximately 6 to 7 volts

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

SelectAnswer
AInsufficient forward voltage
BExcessive inverse voltage
CCharge carrier depletion
DExcessive junction temperature

27. - E6C05

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

SelectAnswer
AImmune to damage from static discharge
BLower distortion
CDifferential output capability
DLower power consumption

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

SelectAnswer
ADirect current
BMagnetizing current
CExcitation current
DStabilizing current

29. - E6E12

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

SelectAnswer
AToo many pins
BUnsuitable for combining analog and digital signals
CExcessive lead length
DEpoxy coating is conductive above 300 MHz

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

SelectAnswer
AHoles
BPhotons
CProtons
DElectrons

31. - E7A07

What logical operation does a NAND gate perform?

SelectAnswer
AIt produces logic 0 at its output only when all inputs are logic 1
BIt produces logic 0 at its output only when all inputs are logic 0
CIt produces logic 0 at its output if some but not all inputs are logic 1
DIt produces logic 1 at its output only when all inputs are logic 1

32. - E7B02

What is a Class D amplifier?

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

33. - E7C10

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

SelectAnswer
AAn L-C filter
BA DSP filter
CA crystal filter
DA cavity filter

34. - E7D08

What type of circuit is shown in Figure E7-2?

SelectAnswer
AGrounded emitter amplifier
BSwitching voltage regulator
CMonostable multivibrator
DLinear voltage regulator

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

SelectAnswer
AProduct detector
BPhase detector
CPhase comparator
DDiscriminator

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

SelectAnswer
AA notch filter
BAn elliptical filter
CA Hilbert-transform filter
DAn adaptive filter

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

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

38. - E7H07

How can an oscillator's microphonic responses be reduced?

SelectAnswer
AIncrease the bias voltage
BUse NP0 capacitors
CMechanically isolate the oscillator circuitry from its enclosure
DReduce noise on the oscillator's power supply

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

SelectAnswer
AA sawtooth wave
BA cosine wave
CA square wave
DA sine wave

40. - E8B11

What is digital time division multiplexing?

SelectAnswer
ATwo or more signals are arranged to share discrete time slots of a data transmission
BTwo or more data streams share the same channel by transmitting time of transmission as the sub-carrier
CTwo or more data streams are assigned to discrete sub-carriers on an FM transmitter
DTwo or more signals are quadrature modulated to increase bandwidth efficiency

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

SelectAnswer
AExtended Binary Coded Decimal Interchange Code
BGray code
CBinary Coded Decimal Code
DExcess 3 code

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

SelectAnswer
ABaud rate
BSignal-to-noise ratio
CIntermodulation Distortion (IMD)
DRepeat Request Rate (RRR)

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

SelectAnswer
A3.85 dB
B2.79 dB
C6.0 dB
D8.15 dB

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

45. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

SelectAnswer
AThe main lobe takeoff angle increases in the downhill direction
BThe horizontal beamwidth increases in the uphill direction
CThe horizontal beamwidth decreases in the downhill direction
DThe main lobe takeoff angle decreases in the downhill direction

46. - E9D08

What happens as the Q of an antenna increases?

SelectAnswer
ASWR bandwidth decreases
BSWR bandwidth increases
CGain is reduced
DMore common-mode current is present on the feed line

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

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

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

SelectAnswer
A5.3 meters
B3.5 meters
C10.6 meters
D4.3 meters

49. - E9G04

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

SelectAnswer
AVoltage and impedance
BResistance and reactance
CResistance and voltage
DReactance and voltage

50. - E9H02

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

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

Figure E5-1

Figure E7-2