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?

Select	Answer
A	The body reacts to electromagnetic radiation from both the E and H fields
B	All these choices are correct
C	Ground reflections and scattering make the field strength vary with location
D	E field and H field radiation intensity peaks can occur at different locations

2. - E1A10

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

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	An Environmental Assessment must be submitted to the FCC
B	A letter of intent must be filed with the Environmental Protection Agency
C	A form FSD-15 must be submitted to the Department of the Interior
D	A proposal must be submitted to the National Park Service

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	All these choices are correct
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	Business-related messages for non-profit organizations
D	Messages intended for users of the maritime satellite service

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 20, 17, 15, 12, and 10 meter bands
B	Only the 40, 20, 17, 15, and 10 meter bands
C	All HF bands
D	Only the 40, 30, 20, 15, 12, and 10 meter bands

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

Select	Answer
A	Each administering VE
B	The VEC coordinating the session
C	The VE session manager
D	The FCC

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must be capable of external RF switching between its input and output networks
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

8. - E2A08

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

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

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color lines are sent sequentially
B	Color is sent in a color burst at the end of each line
C	Color is amplitude modulated on the frequency modulated intensity signal
D	Color information is sent on a 2.8 kHz subcarrier

10. - E2C04

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

Select	Answer
A	Frequencies shared with various unlicensed wireless data services
B	The 60 meter band channel centered on 5373 kHz
C	Cable TV channels 41 through 43
D	HF frequencies where digital communications are permitted

11. - E2D01

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

Select	Answer
A	MSK144
B	APRS
C	WSPR
D	Hellschreiber

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	PACTOR
C	MT63
D	RTTY

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Mountain ranges
B	Bodies of water
C	Forests
D	Urban areas

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Long-path and short-path waves
B	Refracted rays and reflected waves
C	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
D	Independent waves created in the ionosphere that are elliptically polarized

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class A
B	Class B
C	Class M
D	Class X

16. - E4A11

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

Select	Answer
A	Loosely couple the analyzer near the antenna base
B	Connect the antenna feed line directly to the analyzer's connector
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	The transmitter is not properly neutralized
B	There is more power going into the antenna
C	There is an impedance mismatch between the antenna and feed line
D	There is possibly a short to ground in the feed line

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?

Select	Answer
A	14.755 MHz
B	14.445 MHz
C	15.210 MHz
D	13.845 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?

Select	Answer
A	146.34 MHz and 146.61 MHz
B	173.35 MHz and 139.40 MHz
C	146.88 MHz and 146.34 MHz
D	146.10 MHz and 147.30 MHz

20. - E4E06

What is one type of electrical interference that might be caused by a nearby personal computer?

Select	Answer
A	A clicking noise at intervals of a few seconds
B	A loud AC hum in the audio output of your station receiver
C	A whining type noise that continually pulses off and on
D	The appearance of unstable modulated or unmodulated signals at specific frequencies

21. - E5A13

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

Select	Answer
A	Fewer components are needed for the same performance
B	Internal voltages increase
C	Phase shift can become uncontrolled
D	Parasitic effects are minimized

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	Y
C	X
D	G

23. - E5C08

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

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Faraday grid
D	Polar coordinates

24. - E5D09

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

Select	Answer
A	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
B	It is dissipated in the formation of inductive and capacitive fields
C	It is dissipated as kinetic energy in the circuit
D	It is dissipated as heat in the circuit

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Beta cutoff frequency
B	Corner frequency
C	Alpha cutoff frequency
D	Alpha rejection frequency

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Longer carrier retention time
C	Less forward voltage drop
D	More constant reverse avalanche voltage

27. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The feedback loop becomes unstable
B	The comparator changes its output state
C	The IC input can be damaged
D	The comparator enters latch-up

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Ferrite beads
B	Butterworth filters
C	Steel-core toroids
D	Electrolytic capacitors

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon
C	Silicon nitride
D	Gallium nitride

30. - E6F06

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

Select	Answer
A	An ordinary metal
B	A liquid semiconductor
C	A crystalline semiconductor
D	A heavy metal

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

32. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
B	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
C	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
D	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	A filter using lattice-shaped quartz crystals for high-Q performance
B	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
C	A power supply filter made with interlaced quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	To self-resonate at the hum frequency
B	To provide fixed DC bias for Q1
C	It is a brute force filter for the output
D	It bypasses rectifier output ripple around D1

35. - E7E07

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

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

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting 8-bit data to 16-bit data
B	Converting analog signals to digital form
C	Converting digital signals to analog form
D	Converting digital signals from the time domain to the frequency domain

37. - E7G12

What is an operational amplifier?

Select	Answer
A	A digital audio amplifier whose characteristics are determined by components external to the amplifier
B	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
C	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
D	A RF amplifier used in the UHF and microwave regions

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Spurious signals at discrete frequencies
B	Nyquist limit noise
C	Broadband noise
D	Digital conversion noise

39. - E8A08

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

Select	Answer
A	Immunity to out-of-sequence coding reduces spurious responses
B	Very high speed allows digitizing high frequencies
C	All these choices are correct
D	Very low power consumption decreases frequency drift

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?

Select	Answer
A	3000
B	1000
C	0.3
D	3

41. - E8C07

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

Select	Answer
A	5.76 kHz
B	4.8 kHz
C	9.6 kHz
D	15.36 kHz

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	The receiver is always equipped with a digital blanker
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

43. - E9A01

What is an isotropic antenna?

Select	Answer
A	A spacecraft antenna used to direct signals toward Earth
B	A theoretical, omnidirectional antenna used as a reference for antenna gain
C	A horizontally polarized antenna used to compare Yagi antennas
D	A grounded antenna used to measure Earth conductivity

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 computed feed point impedance may be incorrect
D	The antenna will become mechanically unstable

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	450 ohms
C	50 ohms
D	300 ohms

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance increases
B	The radiation resistance increases and the capacitive reactance increases
C	The radiation resistance increases and the capacitive reactance decreases
D	The radiation resistance decreases and the capacitive reactance decreases

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The gamma matching system
B	The omega matching system
C	The delta matching system
D	The stub matching system

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	Very low impedance
B	Very high impedance
C	The same as the input impedance to the generator
D	The same as the characteristic impedance of the line

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant resistance
B	Points with constant reactance
C	SWR
D	Frequency

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To increase receiver sensitivity
B	To prevent receiver overload which reduces pattern nulls
C	To narrow the receiver bandwidth
D	To compensate for isotropic directivity and the antenna effect of feed lines

Figure E7-2