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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A01

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

Select	Answer
A	Lightning protection
B	Reduce received noise
C	Reduce RFI to telephones and home entertainment systems
D	Reduce RF current flow between pieces of equipment

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	300 Hz above the lower band edge
B	3 kHz above the lower band edge
C	The exact lower band edge
D	1 kHz above the lower band edge

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	3 kHz
B	15 kHz
C	20 kHz
D	10 kHz

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

Select	Answer
A	At least 53 dB below
B	At least 73 dB below
C	At least 63 dB below
D	At least 43 dB below

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

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

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Any licensed amateur operator
B	Only General, Advanced or Amateur Extra Class operators
C	Only Technician, General, Advanced or Amateur Extra Class operators
D	Only Amateur Extra Class operators

8. - E2A09

What do the terms L band and S band specify regarding satellite communications?

Select	Answer
A	FM and Digital Store-and-Forward systems
B	The 2 meter and 70 centimeter bands
C	The 23 centimeter and 13 centimeter bands
D	Which sideband to use

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	90
C	30
D	60

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The rules of order for meetings between contest sponsors
B	A method of exchanging information during a contest QSO
C	The most common set of contest rules
D	A standard for submission of electronic contest logs

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
C	All these choices are correct
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK can transmit faster baud rates
B	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
C	Direct FSK occupies less bandwidth
D	Only direct FSK can be decoded by computer

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The F1 layer
B	The F2 layer
C	The D layer
D	The E layer

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Signals reflected back toward the transmitting station
B	Propagation across the geomagnetic equator
C	Successive ionospheric refractions without an intermediate reflection from the ground
D	Propagation away from the great circle bearing between stations

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of x-ray flux to radio flux, correlated to sunspot number
B	UV emissions at 304 angstroms, correlated to the solar flux index
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	The solar emission at 304 GHz, correlated to x-ray flare levels

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Amount of memory
B	Q of the circuit
C	Sampling rate of the analog-to-digital converter
D	All these choices are correct

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Input impedance
B	Output impedance
C	Reflection coefficient
D	All these choices are correct

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	14.445 MHz
B	15.210 MHz
C	14.755 MHz
D	13.845 MHz

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 out of 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 in phase from airplanes passing overhead

20. - E4E06

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

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

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Minimum
B	Maximum
C	L/R
D	R/L

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	One time constant
B	One exponential period
C	An exponential rate of one
D	A time factor of one

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	Polar coordinates
B	Maidenhead grid
C	Elliptical coordinates
D	Faraday grid

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	0.866
C	1.73
D	0.5

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	Alpha cutoff frequency
C	Alpha rejection frequency
D	Corner frequency

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Insufficient forward voltage
B	Excessive inverse voltage
C	Charge carrier depletion
D	Excessive junction temperature

27. - E6C03

What is tri-state logic?

Select	Answer
A	Logic devices that utilize ternary math
B	Logic devices with 0, 1, and high-impedance output states
C	Proprietary logic devices manufactured by Tri-State Devices
D	Low-power logic devices designed to operate at 3 volts

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

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

Select	Answer
A	Lower junction voltage drop
B	Lower transconductance
C	Higher electron mobility
D	Higher noise figures

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Holes
C	Photons
D	Protons

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It stores one bit of data in either a 0 or 1 state
B	It produces a continuous square wave oscillating between 1 and 0
C	It switches momentarily to the opposite binary state and then returns to its original state after a set time
D	It maintains a constant output voltage, regardless of variations in the input voltage

32. - E7B01

For what portion of the signal cycle does each active element in a push-pull Class AB amplifier conduct?

Select	Answer
A	More than 180 degrees but less than 360 degrees
B	The entire cycle
C	Exactly 180 degrees
D	Less than 180 degrees

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	Reactive currents are dissipated in matched resistances
B	It introduces negative resistance to cancel the resistive part of impedance
C	It introduces transconductance to cancel the reactive part of impedance
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

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. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	The two input frequencies along with their sum and difference frequencies
C	The square root of the product of input frequencies
D	Two and four times the original frequency

36. - E7F07

What function is performed by a Fast Fourier Transform?

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

37. - E7G02

What is ringing in a filter?

Select	Answer
A	Partial cancellation of the signal over a range of frequencies
B	An echo caused by a long time delay
C	A reduction in high frequency response
D	Undesired oscillations added to the desired signal

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified voltage
B	Provide the crystal with a specified parallel inductance
C	Provide the crystal with a specified parallel capacitance
D	Bias the crystal at a specified current

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The frequency of the modulating signal
B	Amplifier gain
C	Speech characteristics
D	The degree of carrier suppression

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow-band, slow-speed transmissions
B	A bandwidth compression technique using Fourier transforms
C	A frequency modulation technique that uses non-harmonically related frequencies
D	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

41. - E8C08

How does ARQ accomplish error correction?

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

42. - E8D08

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

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

43. - E9A05

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

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

44. - E9B02

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

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

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	Fewer vertical angle lobes will be present
B	The low-angle radiation increases
C	Additional higher vertical angle lobes will appear
D	The low-angle radiation decreases

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	Solid wire
C	Stranded wire
D	Resistive wire, such as spark plug wire

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The stub match
B	The delta match
C	The gamma match
D	The omega match

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Higher SWR
C	Lower velocity factor
D	Smaller reflection coefficient

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The voltage axis
B	The resistance axis
C	The current axis
D	The reactance axis

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By reducing the permeability of the loop shield
B	By winding adjacent turns in opposing directions
C	By increasing the number of turns and/or the area
D	By utilizing high impedance wire for the coupling loop

Figure E9-1

Figure E9-3