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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
A30 to 300 MHz
B300 kHz to 3 MHz
C300 to 3000 MHz
D3 to 30 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
AAny person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
BOnly a person named in an amateur station license grant
CAny person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
DOnly a person with an FCC Marine Radio license grant

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

SelectAnswer
AUse of wireless devices in a vehicle is exempt from regulation
BNo limitations may be placed on antenna size or placement
CAmateur radio operations must be permitted in any private residence
DReasonable accommodations of amateur radio must be made

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. - 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 Amateur Extra Class operators
COnly those of General, Advanced or Amateur Extra Class operators
DAny amateur station, subject to the privileges of the class of operator license held by the control operator

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

SelectAnswer
AIssue the examinee the new or upgrade license
BAll these choices are correct
CPhotocopy all examination documents and forward them to the FCC for processing
DThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

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 for experimental amateur communications
DTo provide additional spectrum for personal use

8. - E2A05

What do the letters in a satellite's mode designator specify?

SelectAnswer
AThe location of the ground control station
BPower limits for uplink and downlink transmissions
CThe uplink and downlink frequency ranges
DThe polarization of uplink and downlink signals

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

SelectAnswer
AThe vestigial sideband carries the audio information
BVestigial sideband reduces bandwidth while allowing for simple video detector circuitry
CVestigial sideband provides high frequency emphasis to sharpen the picture
DThe vestigial sideband contains chroma information

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

SelectAnswer
AIn the middle of each band, usually on the national calling frequency
BIn the middle of the band, usually 25 kHz above the national calling frequency
CIn the weak signal segment of the band, with most of the activity near the calling frequency
DAt the top of each band, usually in a segment reserved for contests

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

SelectAnswer
AOlivia
BMSK144
CPACTOR III
DJT65

12. - E2E11

What is the difference between direct FSK and audio FSK?

SelectAnswer
AOnly direct FSK can be decoded by computer
BDirect FSK occupies less bandwidth
CDirect FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
DDirect FSK can transmit faster baud rates

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

SelectAnswer
AThe F1 layer
BThe F2 layer
CThe E layer
DThe D layer

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C11

What does VOACAP software model?

SelectAnswer
AHF propagation
BVHF radio propagation
CAC current and impedance
DAC voltage and impedance

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

SelectAnswer
AA false, jittery low-frequency version of the signal is displayed
BExcessive blanking occurs, which prevents display of the signal
CAll signals will have a DC offset
DCalibration of the vertical scale is no longer valid

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

SelectAnswer
AS12
BS11
CS21
DS22

18. - E4C10

What is an advantage of having a variety of receiver IF bandwidths from which to select?

SelectAnswer
AReceiver power consumption can be reduced when wider bandwidth is not required
BMultiple frequencies can be received simultaneously if desired
CThe noise figure of the RF amplifier can be adjusted to match the modulation type, thus increasing receiver sensitivity
DReceive bandwidth can be set to match the modulation bandwidth, maximizing signal-to-noise ratio and minimizing interference

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
CUtilizing a Class D final amplifier
DA properly terminated circulator at the output of the repeater's transmitter

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

SelectAnswer
AOne or more of the broadcast stations is transmitting an over-modulated signal
BYour station receiver IF amplifier stage is defective
CYou are receiving skywave signals from a distant station
DNearby corroded metal joints are mixing and re-radiating the broadcast signals

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

SelectAnswer
A315.6 Hz
B23.67 kHz
C157.8 Hz
D47.3 kHz

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

SelectAnswer
AA positive phase angle
BA negative phase angle
CA negative magnitude
DA positive magnitude

24. - E5D04

Why are short connections used at microwave frequencies?

SelectAnswer
ATo reduce noise figure
BTo increase compensating capacitance
CTo reduce phase shift along the connection
DTo increase neutralizing resistance

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

SelectAnswer
AOnly N-type semiconductor material can conduct current
BExcess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
COnly P-type semiconductor material can conduct current
DHoles in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

SelectAnswer
ATunnel diode
BVaractor diode
CZener diode
DSilicon-controlled rectifier

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

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

28. - E6D01

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

SelectAnswer
AMagnetic flux would increase with frequency
BHarmonics and distortion could result
CTemporary changes of the core permeability could result
DRF susceptance would increase

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

SelectAnswer
ASmaller circuit area
BShorter circuit-board traces
CAll these choices are correct
DComponents have less parasitic inductance and capacitance

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

SelectAnswer
ACopper oxide
BSilicon
CCadmium Sulfide
DSelenium

31. - E7A11

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

SelectAnswer
AAssertive Logic
BPositive Logic
CNegative logic
DReverse Logic

32. - E7B08

How can an RF power amplifier be neutralized?

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

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

34. - E7D15

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

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

35. - E7E04

What is one way a single-sideband phone signal can be generated?

SelectAnswer
ABy driving a product detector with a DSB signal
BBy using a reactance modulator followed by a mixer
CBy using a balanced modulator followed by a filter
DBy using a loop modulator followed by a mixer

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

SelectAnswer
AReference voltage level and sample width in bits
BMissing codes and jitter
CSample clock phase noise
DData storage transfer rate

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

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

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

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 sine wave
BA square wave
CA sawtooth wave
DA cosine wave

40. - E8B11

What is digital time division multiplexing?

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

41. - E8C10

How may data rate be increased without increasing bandwidth?

SelectAnswer
AUsing a more efficient digital code
BIncreasing analog-to-digital conversion resolution
CUsing forward error correction
DIt is impossible

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

SelectAnswer
ABaudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
BBaudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
CBaudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
DBaudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code

43. - E9A05

What is included in the total resistance of an antenna system?

SelectAnswer
ARadiation resistance plus loss resistance
BRadiation resistance plus space impedance
CRadiation resistance plus transmission resistance
DTransmission-line resistance plus radiation resistance

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

SelectAnswer
AThe radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
BThey are the same
CThe total amount of radiation from the directional antenna is stronger by its front-to-back ratio
DThe total amount of radiation from the directional antenna is increased by the gain of the antenna

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

SelectAnswer
AAdditional higher vertical angle lobes will appear
BThe low-angle radiation decreases
CFewer vertical angle lobes will be present
DThe low-angle radiation increases

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

SelectAnswer
ATo lower the losses
BTo increase the SWR bandwidth
CTo cancel capacitive reactance
DTo lower the Q

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

SelectAnswer
AGamma match
BHairpin match
CAll these choices are correct
DDouble-bazooka match

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AThe same as the generator output impedance
BThe same as the characteristic impedance of the transmission line
CVery high impedance
DVery low impedance

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 reactance values with regard to the resistance axis
CReassigning prime center with regard to the reactance axis
DReassigning resistance values with regard to the reactance axis

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
AForward gain compared to the gain in the reverse direction
BForward gain compared to average gain over the entire hemisphere
CRelative directivity compared to a dipole
DRelative directivity compared to isotropic