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

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1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	Any ordinary smoke detector can be used
C	Only with a carbon monoxide detector
D	By the yellowish appearance of the gas

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	50 watts PEP effective radiated power relative to a dipole
B	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C	50 watts PEP effective radiated power relative to an isotropic radiator
D	100 watts PEP effective radiated power relative to an isotropic radiator

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	1.5 kHz
C	2.8 kHz
D	60 Hz

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of General, Advanced or Amateur Extra Class operators
B	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
C	Any amateur station, subject to the privileges of the class of operator license held by the control operator
D	Only those of Amateur Extra Class operators

6. - E1E05

What is the minimum passing score on all amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 80%
C	Minimum passing score of 77%
D	Minimum passing score of 70%

7. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station
D	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers

8. - E2A04

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

Select	Answer
A	The satellite's orientation with respect to the Earth
B	The satellite's uplink and downlink frequency bands
C	Whether the satellite is in a low earth or geostationary orbit
D	Whether the satellite is in a polar or equatorial orbit

9. - E2B05

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

Select	Answer
A	The vestigial sideband carries the audio information
B	The vestigial sideband contains chroma information
C	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry
D	Vestigial sideband provides high frequency emphasis to sharpen the picture

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
C	No additional indicator is required
D	/ followed by the ARRL Section of the remote station

11. - E2D11

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

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

12. - E2E03

How is the timing of FT4 contacts organized?

Select	Answer
A	By exchanging ACK/NAK packets
B	Alternating transmissions at 7.5 second intervals
C	It depends on the lunar phase
D	Stations take turns on alternate days

13. - E3A01

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

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

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the spring equinox
B	Around the solstices, especially the winter solstice
C	Around the solstices, especially the summer solstice
D	Around the equinoxes, especially the fall equinox

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Vertical
B	Elliptical
C	Circular
D	Horizontal

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers display a time-varying representation of the modulation envelope
B	Antenna analyzers do not need an external RF source
C	All these choices are correct
D	Antenna analyzers automatically tune your antenna for resonance

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

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves sensitivity by reducing front end noise
B	It improves dynamic range by attenuating strong signals near the receive frequency
C	It improves intelligibility by using low Q circuitry to reduce ringing
D	All these choices are correct

19. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Squelch gain rollback
B	Cross-modulation interference
C	Quieting
D	Desensitization

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. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
B	It is at a maximum
C	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
D	It is at a minimum

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	110 seconds
B	55 seconds
C	220 seconds
D	440 seconds

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	Far field diagram
C	Phasor diagram
D	Venn diagram

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

Select	Answer
A	1.0
B	0.5
C	0.707
D	0.866

25. - E6A09

What is a depletion-mode FET?

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

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	More constant reverse avalanche voltage
C	Less forward voltage drop
D	Longer carrier retention time

27. - E6C10

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

Select	Answer
A	2
B	1
C	3
D	4

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Temporary changes of the core permeability could result
B	Harmonics and distortion could result
C	Magnetic flux would increase with frequency
D	RF susceptance would increase

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Nearly infinite gain, very high input impedance, and very low output impedance
B	Plate current that is controlled by a control grid
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	Cost per kilowatt-hour generated
B	The relative fraction of light that is converted to current
C	The open-circuit voltage divided by the short-circuit current under full illumination
D	The output RF power divided by the input DC power

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 1
B	It produces logic 1 at its output only when all inputs are logic 1
C	It produces logic 0 at its output only when all inputs are logic 0
D	It produces logic 0 at its output if some but not all inputs are logic 1

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Fixed bias
B	Self bias
C	Output load resistor
D	Emitter bypass

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The amplitude of the signals passing through the filter
B	The DC voltage applied to the quartz crystal
C	The relative frequencies of the individual crystals
D	The gain of the RF stage preceding the filter

34. - E7D07

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

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

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable resistance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce PM signals by using an electrically variable resistance
D	To produce PM or FM signals by using an electrically variable inductance or capacitance

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	10 bits
B	8 bits
C	4 bits
D	6 bits

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It does not vary with frequency
B	It increases linearly with increasing frequency
C	It decreases linearly with increasing frequency
D	It decreases logarithmically with increasing frequency

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Pierce and Zener
B	Colpitts and Hartley
C	Negative feedback and balanced feedback
D	Armstrong and deForest

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Numerical analysis
B	Fourier analysis
C	Differential analysis
D	Vector analysis

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
C	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, a retransmission is requested
B	If errors are detected, redundant data is substituted
C	Special binary codes provide automatic correction
D	Special polynomial codes provide automatic correction

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

43. - E9A09

What is antenna efficiency?

Select	Answer
A	Total resistance divided by radiation resistance
B	Radiation resistance divided by total resistance
C	Effective radiated power divided by transmitter output
D	Radiation resistance divided by transmission resistance

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

Select	Answer
A	38 dB
B	15 dB
C	3 dB
D	28 dB

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
B	A folded dipole center-fed with 300-ohm transmission line
C	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	A multiband dipole antenna using one-way circular polarization for frequency diversity

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize losses
B	To swamp out harmonics
C	To lower the radiation angle
D	To minimize the Q

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

Select	Answer
A	The driven element resonance must be lower than the operating frequency
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element reactance must be inductive
D	The driven element reactance must be capacitive

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

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Beam headings and radiation patterns
B	Trigonometric functions
C	Impedance and SWR values in transmission lines
D	Satellite azimuth and elevation bearings

50. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It should be configured as a four-sided loop
C	It should be one or more wavelengths long
D	It must be mounted more than 1 wavelength above ground

Figure E6-3

Figure E7-1

Figure E7-2