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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

SelectAnswer
AGround reflections and scattering make the field strength vary with location
BThe body reacts to electromagnetic radiation from both the E and H fields
CE field and H field radiation intensity peaks can occur at different locations
DAll these choices are correct

2. - E1A09

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

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

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. - E1C04

What is meant by IARP?

SelectAnswer
AA forecast of intermittent aurora radio propagation
BThe internal amateur radio practices policy of the FCC
CAn international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
DAn indication of increased antenna reflected power

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

SelectAnswer
AOnly the 40, 20, 17, 15, and 10 meter bands
BOnly the 40, 20, 17, 15, 12, and 10 meter bands
COnly the 40, 30, 20, 15, 12, and 10 meter bands
DAll HF bands

6. - E1E09

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

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

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

SelectAnswer
AA line roughly parallel to and east of the U.S. Pacific coastline
BA line roughly parallel to and west of the U.S. Atlantic coastline
CA line roughly parallel to and south of the border between the U.S. and Canada
DA line roughly parallel to and north of the border between the U.S. and Mexico

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

SelectAnswer
ATo delay download of telemetry between satellites
BTo upload operational software for the transponder
CTo store digital messages in the satellite for later download by other stations
DTo relay messages between satellites

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
CThe vestigial sideband contains chroma information
DVestigial sideband provides high frequency emphasis to sharpen the picture

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

SelectAnswer
A30 meters
B6 meters
C2 meters
D33 centimeters

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

SelectAnswer
AAPRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
BAn APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
CAll these choices are correct
DAn APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital

12. - E2E06

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

SelectAnswer
A300 baud
B110 baud
C48 baud
D1200 baud

13. - E3A12

What is the cause of auroral activity?

SelectAnswer
AThe interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
BMeteor showers concentrated in the extreme northern and southern latitudes
CThe interaction in the F2 layer between the solar wind and the Van Allen belt
DAn extreme low-pressure area in the polar regions

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

SelectAnswer
AAround the solstices, especially the winter solstice
BAround the equinoxes, especially the fall equinox
CAround the equinoxes, especially the spring equinox
DAround the solstices, especially the summer solstice

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

SelectAnswer
ADue to the Doppler effect
BDownward bending due to density variations in the atmosphere
CE-region skip
DD-region skip

16. - E4A08

Which of the following measures SWR?

SelectAnswer
AAn antenna analyzer
BA spectrum analyzer
CA Q meter
DAn ohmmeter

17. - E4B11

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

SelectAnswer
AOutput impedance
BReflection coefficient
CAll these choices are correct
DInput impedance

18. - E4C08

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

SelectAnswer
AOne-half the maximum sample rate
BThe reference voltage of the analog-to-digital converter
CThe maximum count value of the analog-to-digital converter
DOne-half the maximum sampling buffer size

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

SelectAnswer
ASpurious signals caused by cross-modulation and desensitization from strong adjacent signals
BOscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
COscillator instability and severe audio distortion of all but the strongest received signals
DCross-modulation of the desired signal and insufficient audio power to operate the speaker

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

SelectAnswer
ABy installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
BBy installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
CBy installing a noise suppression resistor and a blocking capacitor in both leads
DBy connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

21. - E5A05

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

SelectAnswer
AMatching bandwidth is increased
BMatching bandwidth is decreased
CIt has no effect on impedance matching
DMatching range is increased

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

SelectAnswer
A14 degrees with the voltage lagging the current
B76 degrees with the voltage leading the current
C76 degrees with the voltage lagging the current
D14 degrees with the voltage leading the current

23. - E5C10

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 400-ohm resistor and a 38-picofarad capacitor at 14 MHz?

SelectAnswer
APoint 6
BPoint 2
CPoint 5
DPoint 4

24. - E5D05

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

SelectAnswer
A0.5
B1.73
C0.577
D0.866

25. - E6A04

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

SelectAnswer
AInsulator impurity
BDonor impurity
CAcceptor impurity
DN-type impurity

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

SelectAnswer
A1
B7
C5
D6

27. - E6C10

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

SelectAnswer
A3
B1
C4
D2

28. - E6D07

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

SelectAnswer
AStabilizing current
BMagnetizing current
CExcitation current
DDirect current

29. - E6E12

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

SelectAnswer
AUnsuitable for combining analog and digital signals
BToo many pins
CEpoxy coating is conductive above 300 MHz
DExcessive lead length

30. - E6F01

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

SelectAnswer
APhotons
BHoles
CProtons
DElectrons

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

SelectAnswer
A1
B4
C2
D8

32. - E7B04

Where on the load line of a Class A common emitter amplifier would bias normally be set?

SelectAnswer
AWhere the load line intersects the voltage axis
BAt a point where the bias resistor equals the load resistor
CAt a point where the load line intersects the zero bias current curve
DApproximately halfway between saturation and cutoff

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

SelectAnswer
AAn active LC filter
BA Chebyshev filter
CA passive op-amp filter
DA Butterworth filter

34. - E7D01

How does a linear electronic voltage regulator work?

SelectAnswer
AThe conduction of a control element is varied to maintain a constant output voltage
BIt has a ramp voltage as its output
CIt eliminates the need for a pass transistor
DThe control element duty cycle is proportional to the line or load conditions

35. - E7E10

How does a diode envelope detector function?

SelectAnswer
ABy sensing the change of reactance in the diode with respect to frequency
BBy rectification and filtering of RF signals
CBy mixing signals with noise in the transition region of the diode
DBy breakdown of the Zener voltage

36. - E7F13

What is the function of taps in a digital signal processing filter?

SelectAnswer
AProvide access for debugging software
BSelect the point at which baseband signals are generated
CTo reduce excess signal pressure levels
DProvide incremental signal delays for filter algorithms

37. - E7G12

What is an operational amplifier?

SelectAnswer
AA RF amplifier used in the UHF and microwave regions
BA digital audio amplifier whose characteristics are determined by components external to the amplifier
CAn amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
DA high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

SelectAnswer
AArmstrong and deForest
BNegative feedback and balanced feedback
CPierce and Zener
DColpitts and Hartley

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
AVector analysis
BNumerical analysis
CDifferential analysis
DFourier analysis

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

SelectAnswer
A60
B0.167
C0.6
D1.67

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

SelectAnswer
AModulation index and output power
BKeying speed and shape factor (rise and fall time)
CAll these choices are correct
DIF bandwidth and Q

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

SelectAnswer
APhase compandored spread spectrum
BFrequency hopping
CDirect sequence
DBinary phase-shift keying

43. - E9A05

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

SelectAnswer
ARadiation resistance plus loss resistance
BRadiation resistance plus transmission resistance
CTransmission-line resistance plus radiation resistance
DRadiation resistance plus space impedance

44. - E9B06

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

SelectAnswer
A75 degrees
B25 degrees
C7.5 degrees
D45 degrees

45. - E9C05

Which of the following is a type of OCFD antenna?

SelectAnswer
AA multiband dipole antenna using one-way circular polarization for frequency diversity
BA remotely tunable dipole antenna using orthogonally controlled frequency diversity
CA dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
DA folded dipole center-fed with 300-ohm transmission line

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

SelectAnswer
AArrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
BStack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
CArrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
DStack two Yagis fed in phase to form an array with the respective elements in parallel planes

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

SelectAnswer
AReflection coefficient
BDielectric constant
CVelocity factor
DCharacteristic impedance

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AAn inductive reactance
BA capacitive reactance
CZero
DThe same as the characteristic impedance of the line

49. - E9G01

Which of the following can be calculated using a Smith chart?

SelectAnswer
AAntenna radiation pattern
BRadiation resistance
CImpedance along transmission lines
DRadio propagation

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 E6-2

Figure E6-3

Figure E9-2