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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

SelectAnswer
ABlood clotting from the intense magnetic field
BIngestion of ozone gas from the cooling system
CHearing loss caused by high voltage corona discharge
DLocalized heating of the body from RF exposure in excess of the MPE limits

2. - E1A07

What is the maximum power permitted on the 2200 meter band?

SelectAnswer
A50 watts PEP
B100 watts PEP
C5 watts EIRP (Equivalent isotropic radiated power)
D1 watt EIRP (Equivalent isotropic radiated power)

3. - E1B09

Which amateur stations may be operated under RACES rules?

SelectAnswer
AAny FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
BAny FCC-licensed amateur station certified by the responsible civil defense organization for the area served
COnly those club stations licensed to Amateur Extra Class operators
DAny FCC-licensed amateur station except a Technician Class

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

SelectAnswer
AOperations may commence immediately, and may continue unless interference is reported by the UTC
BOperators may not operate until a test signal has been transmitted in coordination with the local power company
COperators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
DOperators must not operate until approval is received

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

SelectAnswer
AAny amateur station so designated by the space station licensee
BAny amateur station so designated by the ITU
CAll these choices are correct
DAny amateur station designated by NASA

6. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

SelectAnswer
AThe amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
BEach General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
CThe prospective VE obtains accreditation from the FCC
DThe procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AAny licensed amateur operator
BOnly General, Advanced or Amateur Extra Class operators
COnly Technician, General, Advanced or Amateur Extra Class operators
DOnly Amateur Extra Class operators

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

SelectAnswer
AThe satellite's uplink and downlink frequency bands
BThe satellite's orientation with respect to the Earth
CWhether the satellite is in a polar or equatorial orbit
DWhether the satellite is in a low earth or geostationary orbit

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

SelectAnswer
AA special front end limiter
BA special notch filter to remove synchronization pulses
CA special IF converter
DNo other hardware is needed

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

SelectAnswer
AA wireless router running custom firmware
BAn optical cable connection between the USB ports of 2 separate computers
CA 440 MHz transceiver with a 9600 baud modem
DA 2 meter VHF transceiver with a 1200 baud modem

11. - E2D10

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

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

12. - E2E08

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

SelectAnswer
AAMTOR
BHellschreiber
CPACTOR
DRTTY

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 E layer
CThe F2 layer
DThe D layer

14. - E3B11

At what time of day can sporadic E propagation occur?

SelectAnswer
AOnly around sunset and sunrise
BOnly around sunset
COnly in hours of darkness
DAny time

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

SelectAnswer
AIt peaks at roughly 14 MHz
BIt increases
CIt decreases
DIt stays the same

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

SelectAnswer
AConnect the analyzer via a high-impedance transformer to the antenna
BConnect the antenna feed line directly to the analyzer's connector
CLoosely couple the antenna and a dummy load to the analyzer
DLoosely couple the analyzer near the antenna base

17. - E4B04

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

SelectAnswer
AS11
BS21
CS22
DS12

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
A14.755 MHz
B14.445 MHz
C13.845 MHz
D15.210 MHz

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

SelectAnswer
A173.35 MHz and 139.40 MHz
B146.88 MHz and 146.34 MHz
C146.10 MHz and 147.30 MHz
D146.34 MHz and 146.61 MHz

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

SelectAnswer
ABy installing a brute-force AC-line filter in series with the motor leads
BBy installing a bypass capacitor in series with the motor leads
CBy using a ground-fault current interrupter in the circuit used to power the motor
DBy installing a high-pass filter in series with the motor's power leads

21. - E5A02

What is resonance in an LC or RLC circuit?

SelectAnswer
AThe highest frequency that will pass current
BThe frequency at which the capacitive reactance equals the inductive reactance
CThe frequency at which the reactive impedance equals the resistive impedance
DThe lowest frequency that will pass current

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

SelectAnswer
A68.2 degrees with the voltage lagging the current
B14.0 degrees with the voltage lagging the current
C14.0 degrees with the voltage leading the current
D68.2 degrees with the voltage leading the current

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

SelectAnswer
AElliptical coordinates
BFaraday grid
CMaidenhead grid
DPolar coordinates

24. - E5D03

What is microstrip?

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

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
CHoles in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
DOnly P-type semiconductor material can conduct current

26. - E6B03

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

SelectAnswer
AZero bias
BReverse bias
CForward bias
DInductive bias

27. - E6C10

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

SelectAnswer
A4
B1
C3
D2

28. - E6D07

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

SelectAnswer
ADirect current
BExcitation current
CStabilizing current
DMagnetizing 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. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt becomes unstable
BIt stays the same
CIt increases
DIt decreases

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 reducing the driving power
CBy feeding a 180-degree out-of-phase portion of the output back to the input
DBy increasing the driving power

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

SelectAnswer
AIt is a high-pass filter
BIt is a low-pass filter
CIt is a notch filter
DIt is a band-pass filter

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

SelectAnswer
AThe resistance of a control element is varied in direct proportion to the line voltage or load current
BThe controlled device's duty cycle is changed to produce a constant average output voltage
CIt is generally less efficient than a linear regulator
DIt gives a ramp voltage at its output

35. - E7E11

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

SelectAnswer
APhase comparator
BPhase detector
CDiscriminator
DProduct detector

36. - E7F03

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

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

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

SelectAnswer
A0.23 volts
B-2.3 volts
C-0.23 volts
D2.3 volts

38. - E7H02

What is a microphonic?

SelectAnswer
AChanges in oscillator frequency due to mechanical vibration
BDistortion caused by RF pickup on the microphone cable
CExcess loading of the microphone by an oscillator
DAn IC used for amplifying microphone signals

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. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

SelectAnswer
A3000
B0.3
C3
D1000

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

SelectAnswer
A9.6 kHz
B4.8 kHz
C5.76 kHz
D15.36 kHz

42. - E8D05

What is the most common method of reducing key clicks?

SelectAnswer
AReduce keying waveform rise and fall times
BIncrease keying waveform rise and fall times
CHigh-pass filters at the transmitter output
DLow-pass filters at the transmitter output

43. - E9A08

What is antenna bandwidth?

SelectAnswer
AThe frequency range over which an antenna satisfies a performance requirement
BThe angle between the half-power radiation points
CThe angle formed between two imaginary lines drawn through the element ends
DAntenna length divided by the number of elements

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

SelectAnswer
A50 degrees
B30 degrees
C25 degrees
D75 degrees

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

SelectAnswer
AOmni-directional
BA figure-8 oriented along the axis of the array
CCardioid
DA figure-8 broadside to the axis of the array

46. - E9D12

Which of the following would provide the best RF ground for your station?

SelectAnswer
AAn electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
BA 50-ohm resistor connected to ground
CAn electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
DAn electrically short connection to a metal water pipe

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

SelectAnswer
A50 ohms
B450 ohms
C75 ohms
D62 ohms

48. - E9F11

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

SelectAnswer
AA capacitive reactance
BInfinite
CAn inductive reactance
DThe same as the characteristic impedance of the line

49. - E9G02

What type of coordinate system is used in a Smith chart?

SelectAnswer
AVoltage lines and current chords
BResistance lines and reactance chords
CResistance circles and reactance arcs
DVoltage circles and current arcs

50. - E9H08

What is the function of a sense antenna?

SelectAnswer
AIt provides diversity reception that cancels multipath signals
BIt modifies the pattern of a DF antenna array to provide a null in one direction
CIt increases the sensitivity of a DF antenna array
DIt allows DF antennas to receive signals at different vertical angles

Figure E6-3

Figure E7-3

Figure E9-1