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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A3 to 30 MHz
B300 to 3000 MHz
C30 to 300 MHz
D300 kHz to 3 MHz

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

SelectAnswer
AOnly a person with an FCC Marine Radio license grant
BAny person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
CAny person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
DOnly a person named in an amateur station license grant

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. - 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
CCEPT agreement
DAll these choices are correct

5. - E1D03

What is a space telecommand station?

SelectAnswer
AAn amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
BAn amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
CAn amateur station that transmits communications to initiate, modify or terminate functions of a space station
DAn amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

SelectAnswer
AA sentence of up to one year in prison
BAll these choices are correct
CRevocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
DA fine of up to $1000 per occurrence

7. - E1F07

When may an amateur station send a message to a business?

SelectAnswer
AWhen the total money involved does not exceed $25
BWhen the control operator is employed by the FCC or another government agency
CWhen neither the amateur nor his or her employer has a pecuniary interest in the communications
DWhen transmitting international third-party communications

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

SelectAnswer
AMulti-satellite relaying
BNode hopping
CStore-and-forward
DDigipeating

9. - E2B04

How is color information sent in analog SSTV?

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

10. - E2C12

What technique do individual nodes use to form a mesh network?

SelectAnswer
AActing as store-and-forward digipeaters
BCustom code plugs for the local trunking systems
CForward error correction and Viterbi codes
DDiscovery and link establishment protocols

11. - E2D04

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

SelectAnswer
AUltrasonics
BBandwidth compressed LORAN
CDoppler shift of beacon signals
DAPRS

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

SelectAnswer
AThe protocol version you are using is not supported by the digital station
BYour transmit frequency is incorrect
CAnother station you are unable to hear is using the frequency
DAll these choices are correct

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

SelectAnswer
AGrayline
BSprites and jets
CWarm and cold fronts
DLightning discharges

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

SelectAnswer
APolar
BSporadic E
CNVIS
DTransequatorial

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

SelectAnswer
AIt prevents oscillation in a low-frequency counter circuit
BIt multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
CIt amplifies low-level signals for more accurate counting
DIt divides a higher frequency signal so a low-frequency counter can display the input frequency

17. - E4B11

Which of the following can be measured with a vector network analyzer?

SelectAnswer
AReflection coefficient
BOutput impedance
CInput impedance
DAll these choices are correct

18. - E4C01

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

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

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

SelectAnswer
AThe minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor
BThe difference in dB between the noise floor and the third-order intercept point
CThe minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
DThe difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression

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. - E5A05

What is the result of increasing the Q of an impedance-matching circuit?

SelectAnswer
AIt has no effect on impedance matching
BMatching bandwidth is increased
CMatching bandwidth is decreased
DMatching range is increased

22. - E5B03

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

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

23. - E5C02

How are impedances described in polar coordinates?

SelectAnswer
ABy X and R values
BBy Y and G values
CBy phase angle and magnitude
DBy real and imaginary parts

24. - E5D03

What is microstrip?

SelectAnswer
AMiniature coax used for low power applications
BShort lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
CPrecision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
DLightweight transmission line made of common zip cord

25. - E6A11

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

SelectAnswer
A2
B6
C3
D1

26. - E6B08

Which of the following is a Schottky barrier diode?

SelectAnswer
AMetal-semiconductor junction
BPIN junction
CElectrolytic rectifier
DThermionic emission diode

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

SelectAnswer
A2
B1
C3
D4

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

SelectAnswer
AMagnetic flux would increase with frequency
BRF susceptance would increase
CHarmonics and distortion could result
DTemporary changes of the core permeability could result

29. - E6E07

What type of transmission line is used for connections to MMICs?

SelectAnswer
ACircular waveguide
BMicrostrip
CMiniature coax
DParallel wire

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

SelectAnswer
AOptoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
BOptoisolators provide a low impedance link between a control circuit and a power circuit
COptoisolators eliminate the effects of reflected light in the control circuit
DOptoisolators provide impedance matching between the control circuit and power circuit

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
AReverse Logic
BAssertive Logic
CPositive Logic
DNegative logic

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

SelectAnswer
ACommon base
BCommon emitter
CCommon collector
DEmitter follower

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

SelectAnswer
APassband ripple
BNoise factor
CPhase response
DShape factor

34. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

SelectAnswer
AA shunt regulator
BA series regulator
CA shunt current source
DA constant current source

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

SelectAnswer
AA beat frequency is generated
BSpurious mixer products are generated
CAutomatic limiting occurs
DMixer blanking occurs

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

SelectAnswer
AMixing products are converted to voltages and subtracted by adder circuits
BA frequency synthesizer removes the unwanted sidebands
CSignals are combined in quadrature phase relationship
DVarying quartz crystal characteristics emulated in digital form

37. - E7G04

What is meant by the "op-amp input offset voltage"?

SelectAnswer
AThe output voltage of the op-amp minus its input voltage
BThe difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
CThe differential input voltage needed to bring the open loop output voltage to zero
DThe potential between the amplifier input terminals of the op-amp in an open loop condition

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
ATaft, Hartley and Pierce
BPierce, Fenner and Beane
CTaft, Pierce and negative feedback
DColpitts, Hartley and Pierce

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

SelectAnswer
APeak envelope power
BPower factor
CReciprocal mixing
DTotal harmonic distortion

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. - E8C08

How does ARQ accomplish error correction?

SelectAnswer
AIf errors are detected, a retransmission is requested
BSpecial polynomial codes provide automatic correction
CSpecial binary codes provide automatic correction
DIf errors are detected, redundant data is substituted

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

SelectAnswer
AThe generation of key clicks
BMore difficult to copy
CThe generation of RF harmonics
DLimits data speed

43. - E9A03

What is the radiation resistance of an antenna?

SelectAnswer
AThe specific impedance of the antenna
BThe combined losses of the antenna elements and feed line
CThe resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
DThe value of a resistance that would dissipate the same amount of power as that radiated from an antenna

44. - E9B06

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

SelectAnswer
A45 degrees
B25 degrees
C75 degrees
D7.5 degrees

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

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

SelectAnswer
AThe SWR is reduced
BThe front-to-back ratio increases
CThe frequency response is widened over the whole frequency band
DThe front-to-back ratio decreases

47. - E9E08

What is a use for a Wilkinson divider?

SelectAnswer
AIt is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
BIt is used to feed low-impedance loads from a high-impedance source
CIt is used to feed high-impedance antennas from a low-impedance source
DIt divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

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
B10.6 meters
C3.5 meters
D4.3 meters

49. - E9G08

What is the process of normalization with regard to a Smith chart?

SelectAnswer
AReassigning impedance values with regard to the prime center
BReassigning prime center with regard to the reactance axis
CReassigning resistance values with regard to the reactance axis
DReassigning reactance values with regard to the resistance axis

50. - E9H09

What is a Pennant antenna?

SelectAnswer
AA four-element, high-gain vertical array invented by George Pennant
BA small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms
CA stealth antenna built to look like a flagpole
DA form of rhombic antenna terminated in a variable capacitor to provide frequency diversity

Figure E6-1

Figure E6-3

Figure E7-1

Figure E9-2