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

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	An unrestricted Radiotelephone Operator Permit
B	Any amateur license with an FCC Marine or Aircraft endorsement
C	Any FCC-issued amateur license
D	Only General Class or higher amateur licenses

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
B	Only those club stations licensed to Amateur Extra Class operators
C	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
D	Any FCC-licensed amateur station except a Technician Class

4. - E1C02

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

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

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

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

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Destroy the application form
C	Return the application document to the examinee
D	Send the application form to the FCC and inform the FCC of the grade

7. - E1F09

Which of the following conditions apply when transmitting spread spectrum emissions?

Select	Answer
A	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
B	The transmission must not be used to obscure the meaning of any communication
C	All these choices are correct
D	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions

8. - E2A13

Which of the following techniques is normally used by low Earth orbiting digital satellites to relay messages around the world?

Select	Answer
A	Multi-satellite relaying
B	Store-and-forward
C	Digipeating
D	Node hopping

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)?

Select	Answer
A	A special IF converter
B	A special notch filter to remove synchronization pulses
C	No other hardware is needed
D	A special front end limiter

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	At the top of each band, usually in a segment reserved for contests
B	In the middle of the band, usually 25 kHz above the national calling frequency
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of each band, usually on the national calling frequency

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Time and frequency
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Latitude and longitude

12. - E2E08

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

Select	Answer
A	RTTY
B	AMTOR
C	PACTOR
D	Hellschreiber

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	100 miles to 300 miles
C	10 miles to 50 miles
D	2500 miles

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Any time
B	Only in hours of darkness
C	Only around sunset
D	Only around sunset and sunrise

15. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	Waning sunspot numbers
C	An extreme geomagnetic storm
D	Very low solar activity

16. - E4A03

Which of the following test instruments is used to display spurious signals and/or intermodulation distortion products generated by an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A wattmeter
C	A logic analyzer
D	A spectrum 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	Input attenuator accuracy
C	Decade divider accuracy
D	Time base accuracy

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Capture effect
B	Desensitization
C	Frequency discrimination
D	Cross-modulation interference

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals cause feedback 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 mix 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. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Common-mode current
B	Differential-mode current
C	Return current
D	Reactive current only

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage and current are in phase
B	The current leads the voltage by 90 degrees
C	The voltage and current are 180 degrees out of phase
D	The voltage leads the current by 90 degrees

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

Select	Answer
A	It is unchanged
B	It is shifted by 90 degrees
C	It becomes the reciprocal
D	The sign is reversed

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Near field diagram
B	Venn diagram
C	Far field diagram
D	Phasor diagram

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor increase the impedance

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that has no current flow between source and drain when no gate voltage is applied
B	Any FET for which holes are the majority carriers
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	Any FET without a channel

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As a high-voltage rectifier
B	As a constant current source
C	As a constant voltage source
D	As an RF detector

27. - E6C10

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

Select	Answer
A	4
B	1
C	3
D	2

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores exhibit greater hysteresis
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores confine most of the magnetic field within the core material
D	Toroidal cores have lower Q characteristics

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	Package mounts in a direct inverted position
C	Low leakage doubly insulated package
D	Two chips in each package (Dual In Package)

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An LED and a phototransistor
B	A lens and a photomultiplier
C	An amplitude modulated helium-neon laser
D	A frequency modulated helium-neon laser

31. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A diagram showing logic states when the digital device output is true
C	A list of inputs and corresponding outputs for a digital device
D	A table of logic symbols that indicate the logic states of an op-amp

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers operate at higher voltages
B	Switching amplifiers use push-pull circuits
C	Linear amplifiers have high gain resulting in higher harmonic content
D	The power transistor is at saturation or cutoff most of the time

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Phase Inverter Load network
B	A matching network in which all components are isolated from ground
C	A network with only three discrete parts
D	A Pi-network with an additional series inductor on the output

34. - E7D02

What is a characteristic of a switching electronic voltage regulator?

Select	Answer
A	It is generally less efficient than a linear regulator
B	The resistance of a control element is varied in direct proportion to the line voltage or load current
C	It gives a ramp voltage at its output
D	The controlled device's duty cycle is changed to produce a constant average output voltage

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A pre-emphasis network
B	A de-emphasis network
C	A heterodyne suppressor
D	A heterodyne enhancer

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	4 bits
B	10 bits
C	6 bits
D	8 bits

37. - E7G12

What is an operational amplifier?

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

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Pierce, Fenner and Beane
C	Colpitts, Hartley and Pierce
D	Taft, Hartley and Pierce

39. - E8A08

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

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

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	High-speed digital modes
B	OFDM signals are not allowed on amateur bands
C	Extremely low-power contacts
D	EME

41. - E8C02

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

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The number of control characters in a message packet
C	The rate at which the waveform changes to convey information
D	The duration of each bit in a message sent over the air

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive numbers of retries
C	Excessive transmit audio levels
D	Bit errors in the modem

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus loss resistance
B	Radiation resistance plus space impedance
C	Radiation resistance plus transmission resistance
D	Transmission-line resistance plus radiation resistance

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	24 dB
B	14 dB
C	18 dB
D	36 dB

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A half-wave dipole with an additional parallel wire connecting its two ends
B	A dipole configured to provide forward gain
C	A type of ground-plane antenna
D	A dipole one-quarter wavelength long

46. - E9D12

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

Select	Answer
A	An electrically short connection to a metal water pipe
B	A 50-ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
B	It is used to feed high-impedance antennas from a low-impedance source
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed low-impedance loads from a high-impedance source

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?

Select	Answer
A	Foam dielectric has lower safe operating voltage limits
B	Foam dielectric has higher velocity factor
C	Foam dielectric has lower loss per unit of length
D	All these choices are correct

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Voltage and impedance
B	Resistance and reactance
C	Resistance and voltage
D	Reactance and voltage

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station plots three headings to the signal source
B	A fixed receiving station uses three different antennas to plot the location of the signal source
C	Antenna headings from several different receiving locations are used to locate the signal source
D	The geometric angles of sky waves from the source are used to determine its position

Figure E6-3

Figure E9-1