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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	The high gain antennas commonly used can result in high exposure levels
C	Microwaves often travel long distances by ionospheric reflection
D	Microwaves are ionizing radiation

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	On any frequency where the signal's sidebands are within the channel
C	At the lowest frequency of the channel
D	At the center frequency of the channel

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	Use of wireless devices in vehicles
B	State and local zoning
C	FAA tower height limits
D	Homeowners associations

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	0.5
C	2.0
D	3.0

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)?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the space station licensee
C	Any amateur station so designated by the ITU
D	All these choices are correct

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
B	A person who has volunteered to prepare amateur operator license examinations
C	A person who has volunteered to administer amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be the VE session manager

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have political content, except as allowed by the Fairness Doctrine
B	Communications that have religious content
C	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
D	Communications in a language other than English

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent the satellite from emitting out-of-band signals
B	To avoid reducing the downlink power to all other users
C	To avoid interfering with terrestrial QSOs
D	To prevent creating errors in the satellite telemetry

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Luminance
B	Spectral intensity
C	Chroma
D	Hue

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Discovery and link establishment protocols
B	Custom code plugs for the local trunking systems
C	Acting as store-and-forward digipeaters
D	Forward error correction and Viterbi codes

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	APRS
B	WSPR
C	Hellschreiber
D	MSK144

12. - E2E06

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

Select	Answer
A	1200 baud
B	110 baud
C	300 baud
D	48 baud

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	12,000 miles, if the moon is visible by both stations
B	5000 miles, if the moon is at perigee
C	2000 miles, if the moon is at apogee
D	500 miles, if the moon is at perigee

14. - E3B02

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

Select	Answer
A	7500 miles
B	2500 miles
C	5000 miles
D	1000 miles

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

Select	Answer
A	A temperature inversion has occurred
B	Increased transequatorial propagation is likely
C	A solar flare has occurred
D	Long-path propagation is likely

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Logic analyzer
B	Modulation monitor
C	Bit error rate tester
D	Network analyzer

17. - E4B01

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

Select	Answer
A	Temperature coefficient of the logic
B	Decade divider accuracy
C	Time base accuracy
D	Input attenuator accuracy

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
B	The minimum detectable signal as a function of receive frequency
C	The galactic noise contribution to minimum detectable signal
D	The noise figure of a 1 Hz bandwidth receiver

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
B	When the signals from the transmitters are reflected in phase from airplanes passing overhead
C	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
D	When the signals from the transmitters are reflected out of phase from airplanes passing overhead

20. - E4E11

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

Select	Answer
A	Your station receiver IF amplifier stage is defective
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	You are receiving skywave signals from a distant station
D	One or more of the broadcast stations is transmitting an over-modulated signal

21. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Reactance of either the inductance or capacitance divided by the resistance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Resistance divided by the reactance of either the inductance or capacitance

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?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage leading the current
C	76 degrees with the voltage lagging the current
D	14 degrees with the voltage lagging the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 3
B	Point 8
C	Point 1
D	Point 7

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	252 W
B	704 W
C	1.42 mW
D	355 W

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has higher input impedance
B	They are both high impedance
C	An FET has lower input impedance
D	They are both low impedance

26. - E6B03

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

Select	Answer
A	Zero bias
B	Inductive bias
C	Reverse bias
D	Forward bias

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	5
B	6
C	2
D	4

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally require fewer turns to produce a given inductance

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
B	Low leakage doubly insulated package
C	Package mounts in a direct inverted position
D	Two chips in each package (Dual In Package)

30. - E6F10

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

Select	Answer
A	Silicon
B	Selenium
C	Copper oxide
D	Cadmium Sulfide

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 0 at its output if only one input is logic 1
B	It produces logic 0 at its output only if all inputs are logic 0
C	It produces logic 1 at its output if only one input is logic 1
D	It produces logic 1 at its output only if all inputs are logic 1

32. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding a 180-degree out-of-phase portion of the output back to the input
B	By feeding an in-phase component of the output back to the input
C	By reducing the driving power
D	By increasing the driving power

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A crystal filter
B	A cavity filter
C	A DSP filter
D	An L-C filter

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Minimum input voltage for rated power dissipation
B	Minimum input-to-output voltage required to maintain regulation
C	Maximum that the output voltage may decrease at rated load
D	Maximum output voltage drops when the input voltage is varied over its specified range

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The lowest frequency band that the transmitter or receiver covers
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The unmodulated bandwidth of the transmitted signal
D	The frequency range occupied by a message signal prior to modulation

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	A frequency synthesizer removes the unwanted sidebands
B	Mixing products are converted to voltages and subtracted by adder circuits
C	Varying quartz crystal characteristics emulated in digital form
D	Signals are combined in quadrature phase relationship

37. - E7G01

What is the typical output impedance of an op-amp?

Select	Answer
A	Very low
B	100 ohms
C	1000 ohms
D	Very high

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a capacitive divider
C	Through a tapped coil
D	Through link coupling

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?

Select	Answer
A	A sine wave
B	A cosine wave
C	A sawtooth wave
D	A square wave

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal jumps from band to band at a predetermined rate
B	The transmitted signal is divided into packets of information
C	Two or more information streams are merged into a baseband, which then modulates the transmitter
D	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Reed-Solomon character encoding
C	Use of sinusoidal data pulses
D	Use of trapezoidal data pulses

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Repeat Request Rate (RRR)
B	Signal-to-noise ratio
C	Baud rate
D	Intermodulation Distortion (IMD)

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	2.79 dB
B	6.0 dB
C	8.15 dB
D	3.85 dB

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	Ground conductivity will not be accurately modeled
B	The resulting design will favor radiation of harmonic energy
C	The antenna will become mechanically unstable
D	The computed feed point impedance may be incorrect

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

Select	Answer
A	The horizontal beamwidth decreases
B	The horizontal beamwidth increases
C	The takeoff angle of the lowest elevation lobe decreases
D	The takeoff angle of the lowest elevation lobe increases

46. - E9D11

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

Select	Answer
A	Wide flat copper strap
B	Stranded wire
C	Solid wire
D	Resistive wire, such as spark plug wire

47. - E9E04

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

Select	Answer
A	To provide a rejection notch that prevents the radiation of harmonics
B	To transform the antenna impedance to a higher value
C	To provide DC isolation between the feed line and the antenna
D	To cancel the inductive reactance of the matching network

48. - E9F10

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

Select	Answer
A	A capacitive reactance
B	An inductive reactance
C	The same as the characteristic impedance of the line
D	Zero

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning impedance values with regard to the prime center
B	Reassigning prime center with regard to the reactance axis
C	Reassigning resistance values with regard to the reactance axis
D	Reassigning reactance values with regard to the resistance axis

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It increases signal strength by providing a better match to the feed line
B	It eliminates tracking errors caused by strong out-of-band signals
C	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
D	It adds capacitive loading, increasing the bandwidth of the antenna

Figure E5-1

Figure E6-3