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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

SelectAnswer
AReduce RFI to telephones and home entertainment systems
BLightning protection
CReduce RF current flow between pieces of equipment
DReduce received noise

2. - E1A07

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

SelectAnswer
A50 watts PEP
B1 watt EIRP (Equivalent isotropic radiated power)
C100 watts PEP
D5 watts EIRP (Equivalent isotropic radiated power)

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

SelectAnswer
AYou may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
BYou must submit engineering drawings to the FAA
CYou must file an Environmental Impact Statement with the EPA before construction begins
DYou must obtain a construction permit from the airport zoning authority

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. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

SelectAnswer
A100 watts
B5 watts
C1 watt
D2 watts

6. - E1E03

What is a Volunteer Examiner Coordinator?

SelectAnswer
AThe person who has entered into an agreement with the FCC to be the VE session manager
BA person who has volunteered to prepare amateur operator license examinations
CAn organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
DA person who has volunteered to administer amateur operator license examinations

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

SelectAnswer
AThe operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
BFull privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
CNone, they must obtain a U.S. license
DAll privileges of the Amateur Extra Class license

8. - E2A05

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

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

9. - E2B05

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

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

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

SelectAnswer
AFrequencies shared with various unlicensed wireless data services
BHF frequencies where digital communications are permitted
CThe 60 meter band channel centered on 5373 kHz
DCable TV channels 41 through 43

11. - E2D06

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

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

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

SelectAnswer
ADTMF tones modulating an FM signal
BSpread spectrum
CPulse modulation
DFSK

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

SelectAnswer
A28 MHz - 148 MHz
B1.8 MHz - 1.9 MHz
C10 MHz - 14 MHz
D220 MHz - 450 MHz

14. - E3B02

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

SelectAnswer
A7500 miles
B5000 miles
C2500 miles
D1000 miles

15. - E3C01

What does the radio communication term "ray tracing" describe?

SelectAnswer
ADetermining the radiation pattern from an array of antennas
BModeling a radio wave's path through the ionosphere
CEvaluating high voltage sources for x-rays
DThe process in which an electronic display presents a pattern

16. - E4A11

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

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

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

SelectAnswer
ADecade divider accuracy
BInput attenuator accuracy
CTemperature coefficient of the logic
DTime base accuracy

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
COne-half the maximum sampling buffer size
DThe maximum count value of the analog-to-digital converter

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

SelectAnswer
ARaise the receiver IF frequency
BDecrease the RF bandwidth of the receiver
CIncrease the receiver front end gain
DSwitch from fast AGC to slow AGC

20. - E4E11

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

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

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
A23.67 kHz
B157.8 Hz
C315.6 Hz
D47.3 kHz

22. - E5B03

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

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

SelectAnswer
AMaidenhead grid
BElliptical coordinates
CFaraday grid
DRectangular coordinates

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

SelectAnswer
A1000 watts
B600 watts
C200 watts
D1600 watts

25. - E6A04

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

SelectAnswer
AInsulator impurity
BAcceptor impurity
CN-type impurity
DDonor impurity

26. - E6B04

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

SelectAnswer
AVaractor diode
BTunnel diode
CSilicon-controlled rectifier
DZener diode

27. - E6C09

What is a Programmable Logic Device (PLD)?

SelectAnswer
AProgrammable equipment used for testing digital logic integrated circuits
BA type of transistor whose gain can be changed by digital logic circuits
CA programmable collection of logic gates and circuits in a single integrated circuit
DA logic circuit that can be modified during use

28. - E6D02

What is the equivalent circuit of a quartz crystal?

SelectAnswer
AMotional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
BMotional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
CMotional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
DMotional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

SelectAnswer
A2 dB
B-20 dBm
C-10 dB
D44 dBm

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

SelectAnswer
AA liquid semiconductor
BAn ordinary metal
CA crystalline semiconductor
DA heavy metal

31. - E7A01

Which circuit is bistable?

SelectAnswer
AA bipolar amplifier
BA flip-flop
CAn AND gate
DAn OR gate

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

SelectAnswer
ABecause they are relatively far in frequency from the desired signal
BBecause they maintain the sidebands, thus causing multiple duplicate signals
CBecause they invert the sidebands causing distortion
DBecause they are relatively close in frequency to the desired signal

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

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

SelectAnswer
AMinimum input voltage for rated power dissipation
BMaximum output voltage drops when the input voltage is varied over its specified range
CMaximum that the output voltage may decrease at rated load
DMinimum input-to-output voltage required to maintain regulation

35. - E7E06

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

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

36. - E7F08

What is the function of decimation?

SelectAnswer
AReducing the effective sample rate by removing samples
BConverting data to binary code decimal form
CAttenuating the signal
DRemoving unnecessary significant digits

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

SelectAnswer
A38
B1
C76
D0.03

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

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

SelectAnswer
AAn error caused by irregular quantization step size
BA method of decimation by randomly skipping samples
CAn abnormal condition where the converter cannot settle on a value to represent the signal
DA small amount of noise added to the input signal to allow more precise representation of a signal over time

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
ATwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
BTwo or more information streams are merged into a baseband, which then modulates the transmitter
CThe transmitted signal jumps from band to band at a predetermined rate
DThe transmitted signal is divided into packets of information

41. - E8C02

What is the definition of symbol rate in a digital transmission?

SelectAnswer
AThe number of control characters in a message packet
BThe number of characters carried per second by the station-to-station link
CThe rate at which the waveform changes to convey information
DThe duration of each bit in a message sent over the air

42. - E8D01

Why are received spread spectrum signals resistant to interference?

SelectAnswer
AIf interference is detected by the receiver it will signal the transmitter to change frequencies
BThe high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
CThe receiver is always equipped with a digital blanker
DSignals not using the spread spectrum algorithm are suppressed in the receiver

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

SelectAnswer
AAntenna height
BThe settings of an antenna tuner at the transmitter
CThe input power level
DTransmission line length

44. - E9B10

What is the principle of a Method of Moments analysis?

SelectAnswer
AA wire is modeled as a single sine-wave current generator
BA wire is modeled as a series of segments, each having a distinct value of voltage across it
CA wire is modeled as a single sine-wave voltage source
DA wire is modeled as a series of segments, each having a uniform value of current

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
ACardioid
BA figure-8 oriented along the axis of the array
CA figure-8 broadside to the axis of the array
DOmni-directional

46. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

SelectAnswer
AAs low as possible on the vertical radiator
BNear the center of the vertical radiator
CAs close to the transmitter as possible
DAt a voltage node

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

SelectAnswer
AIt ensures that each driven element operates in concert with the others to create the desired antenna pattern
BIt creates a low-angle radiation pattern
CIt allows single-band antennas to operate on other bands
DIt prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter

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
A10.6 meters
B3.5 meters
C5.3 meters
D4.3 meters

49. - E9G01

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

SelectAnswer
AAntenna radiation pattern
BRadio propagation
CImpedance along transmission lines
DRadiation resistance

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 E7-3