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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

SelectAnswer
AOnly commercial transmitters
BOnly the most powerful transmitter
CEach transmitter operating with a duty cycle greater than 50 percent
DEach transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

SelectAnswer
AThe amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
BThe amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
CIts operation must be approved by the master of the ship or the pilot in command of the aircraft
DThe amateur station must have a power supply that is completely independent of the main ship or aircraft power supply

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

SelectAnswer
AThe amateur station must cease operation on all frequencies below 30 MHz
BThe amateur station must cease operation
CThe amateur station must cease operation on all frequencies above 30 MHz
DThe amateur station must avoid transmitting during certain hours on frequencies that cause the interference

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

SelectAnswer
AAt least 53 dB below
BAt least 63 dB below
CAt least 73 dB below
DAt least 43 dB below

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A70 cm and 13 cm
B33 cm and 13 cm
C70 cm and 33 cm
D70 cm only

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
APhotocopy all examination documents and forward them to the FCC for processing
BIssue the examinee the new or upgrade license
CThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
DAll these choices are correct

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

SelectAnswer
A420 MHz - 430 MHz
B222 MHz - 223 MHz
C440 MHz - 450 MHz
D53 MHz - 54 MHz

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 store digital messages in the satellite for later download by other stations
CTo relay messages between satellites
DTo upload operational software for the transponder

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
AAmplitude modulation in which one complete sideband and a portion of the other are transmitted
BNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
CSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
DA type of modulation in which one sideband is inverted

10. - E2C03

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

SelectAnswer
A33 centimeters
B2 meters
C6 meters
D30 meters

11. - E2D06

Which of the following describes a method of establishing EME contacts?

SelectAnswer
AStoring and forwarding digital messages
BTime synchronous transmissions alternately from each station
CHigh-speed CW identification to avoid fading
DJudging optimum transmission times by monitoring beacons reflected from the moon

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
APACTOR
BRTTY
CAMTOR
DHellschreiber

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 E layer
BThe F1 layer
CThe D layer
DThe F2 layer

14. - E3B02

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

SelectAnswer
A1000 miles
B2500 miles
C5000 miles
D7500 miles

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

SelectAnswer
A50 percent greater
BFour times as great
CTwice as great
D10 percent greater

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
BCalibration of the vertical scale is no longer valid
CAll signals will have a DC offset
DExcessive blanking occurs, which prevents display of the signal

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
AThe port or ports at which measurements are made
BRelative quality of the data
CFrequency order of the measurements
DThe relative time between measurements

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

SelectAnswer
A14.445 MHz
B15.210 MHz
C14.755 MHz
D13.845 MHz

19. - E4D03

How can intermodulation interference between two repeaters occur?

SelectAnswer
AWhen the signals from the transmitters are reflected in phase from airplanes passing overhead
BWhen the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
CWhen the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
DWhen the signals from the transmitters are reflected out of phase from airplanes passing overhead

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

SelectAnswer
AIgnition noise
BBroadband white noise
CPower line noise
DAll these choices are correct

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

SelectAnswer
AInternal voltages increase
BParasitic effects are minimized
CPhase shift can become uncontrolled
DFewer components are needed for the same performance

22. - E5B12

What is admittance?

SelectAnswer
AThe turns ratio of a transformer
BThe term for the gain of a field effect transistor
CThe inverse of Q factor
DThe inverse of impedance

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

SelectAnswer
AOn the horizontal axis
BOn the vertical axis
COn a line through the origin, slanted at 45 degrees
DOn a horizontal line, offset vertically above the horizontal axis

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

SelectAnswer
AIt is dissipated as kinetic energy in the circuit
BIt is dissipated in the formation of inductive and capacitive fields
CIt is dissipated as heat in the circuit
DIt is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated

25. - E6A09

What is a depletion-mode FET?

SelectAnswer
AAny FET without a channel
BAn FET that exhibits a current flow between source and drain when no gate voltage is applied
CAn FET that has no current flow between source and drain when no gate voltage is applied
DAny FET for which holes are the majority carriers

26. - E6B03

What type of bias is required for an LED to emit light?

SelectAnswer
AReverse bias
BInductive bias
CForward bias
DZero bias

27. - E6C01

What is the function of hysteresis in a comparator?

SelectAnswer
ATo allow the comparator to be used with AC input signals
BTo prevent input noise from causing unstable output signals
CTo increase the sensitivity
DTo cause the output to change states continually

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
CDirect current
DExcitation current

29. - E6E12

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

SelectAnswer
AExcessive lead length
BToo many pins
CUnsuitable for combining analog and digital signals
DEpoxy coating is conductive above 300 MHz

30. - E6F01

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

SelectAnswer
AHoles
BElectrons
CProtons
DPhotons

31. - E7A04

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

SelectAnswer
A8
B4
C1
D2

32. - E7B08

How can an RF power amplifier be neutralized?

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

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
ATwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
BA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
CTwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
DAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output

34. - E7D09

What is the main reason to use a charge controller with a solar power system?

SelectAnswer
AControl of electrolyte levels during battery discharge
BMatching of day and night charge rates
CPrevention of battery undercharge
DPrevention of battery damage due to overcharge

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

SelectAnswer
AFor compatibility with transmitters using phase modulation
BFor higher efficiency
CTo remove third-order distortion products
DTo reduce impulse noise reception

36. - E7F13

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

SelectAnswer
ATo reduce excess signal pressure levels
BProvide access for debugging software
CProvide incremental signal delays for filter algorithms
DSelect the point at which baseband signals are generated

37. - E7G04

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

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

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
AColpitts, Hartley and Pierce
BTaft, Hartley and Pierce
CTaft, Pierce and negative feedback
DPierce, Fenner and Beane

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

SelectAnswer
AVery high speed allows digitizing high frequencies
BAll these choices are correct
CVery low power consumption decreases frequency drift
DImmunity to out-of-sequence coding reduces spurious responses

40. - E8B01

What is the modulation index of an FM signal?

SelectAnswer
AThe type of modulation used by the transmitter
BThe ratio of frequency deviation to modulating signal frequency
CThe ratio of modulating signal amplitude to frequency deviation
DThe bandwidth of the transmitted signal divided by the modulating signal frequency

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

SelectAnswer
A1.0 kHz
B0.1 Hz
C0.5 kHz
D0.3 kHz

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
BDirect sequence
CFrequency hopping
DBinary phase-shift keying

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

SelectAnswer
A78.7 watts
B286 watts
C420 watts
D1977 watts

44. - E9B08

What is the far field of an antenna?

SelectAnswer
AThe region of the ionosphere where radiated power is not refracted
BThe region where radiated power dissipates over a specified time period
CThe region where the shape of the antenna pattern is independent of distance
DThe region where radiated field strengths are constant

45. - E9C10

Which of the following describes a Zepp antenna?

SelectAnswer
AAn end-fed dipole antenna
BA dipole constructed from zip cord
CAn omni-directional antenna commonly used for satellite communications
DA vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
AStranded wire
BWide flat copper strap
CSolid wire
DResistive wire, such as spark plug wire

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

SelectAnswer
ATo provide a rejection notch that prevents the radiation of harmonics
BTo provide DC isolation between the feed line and the antenna
CTo cancel the inductive reactance of the matching network
DTo transform the antenna impedance to a higher value

48. - E9F08

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

SelectAnswer
AAll these choices are correct
BFoam dielectric has higher velocity factor
CFoam dielectric has lower safe operating voltage limits
DFoam dielectric has lower loss per unit of length

49. - E9G03

Which of the following is often determined using a Smith chart?

SelectAnswer
AImpedance and SWR values in transmission lines
BSatellite azimuth and elevation bearings
CBeam headings and radiation patterns
DTrigonometric functions

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

SelectAnswer
ABy winding adjacent turns in opposing directions
BBy increasing the number of turns and/or the area
CBy reducing the permeability of the loop shield
DBy utilizing high impedance wire for the coupling loop