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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
B	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
C	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits
D	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits

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

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in Florida surrounding Cape Canaveral
B	An area in Puerto Rico surrounding the Arecibo Radio Telescope
C	An area in New Mexico surrounding the White Sands Test Area
D	An area surrounding the National Radio Astronomy Observatory

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
B	A special endorsement must be requested from the FCC
C	An environmental impact statement must be filed with the Department of the Interior
D	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

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

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Photocopy all examination documents and forward them to the FCC for processing
B	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
C	All these choices are correct
D	Issue the examinee the new or upgrade license

7. - E1F10

Who may be the control operator of an auxiliary station?

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

8. - E2A08

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

Select	Answer
A	To avoid reducing the downlink power to all other users
B	To prevent the satellite from emitting out-of-band signals
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	Hue
B	Luminance
C	Spectral intensity
D	Chroma

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

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	PSK
B	RTTY
C	Multi-tone AFSK
D	IEEE 802.11

12. - E2E09

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

Select	Answer
A	PACTOR
B	RTTY
C	PSK31
D	MT63

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	RTTY
B	FM
C	CW
D	SSB

14. - E3B02

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

Select	Answer
A	1000 miles
B	5000 miles
C	7500 miles
D	2500 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 solar flare has occurred
B	A temperature inversion has occurred
C	Increased transequatorial propagation is likely
D	Long-path propagation is likely

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It divides a higher frequency signal so a low-frequency counter can display the input frequency
B	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It amplifies low-level signals for more accurate counting

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and resonant circuit
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	50 ohms, 75 ohms, and 90 ohms
D	Short circuit, open circuit, and 50 ohms

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	RAM speed used for data storage
B	Analog-to-digital converter sample width in bits
C	Anti-aliasing input filter bandwidth
D	CPU register width in bits

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To provide a range of AGC time constants
B	To allow selection of the optimum RF amplifier device
C	To increase rejection of signals outside the desired band
D	To store often-used frequencies

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Broadband white noise
B	Power line noise
C	All these choices are correct
D	Ignition noise

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	Parasitic effects are minimized
C	Internal voltages increase
D	Phase shift can become uncontrolled

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

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By X and R values
B	By real and imaginary parts
C	By Y and G values
D	By phase angle and magnitude

24. - E5D03

What is microstrip?

Select	Answer
A	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
B	Miniature coax used for low power applications
C	Lightweight transmission line made of common zip cord
D	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In very low-frequency RF circuits
B	In high-power audio circuits
C	In high-current rectifier circuits
D	In microwave circuits

26. - E6B09

What is a common use for point-contact diodes?

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

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To prevent input noise from causing unstable output signals
B	To cause the output to change states continually
C	To increase the sensitivity
D	To allow the comparator to be used with AC input signals

28. - E6D05

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

Select	Answer
A	Ferrite toroids are easier to use with surface mount technology
B	Ferrite toroids generally require fewer turns to produce a given inductance value
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally have better temperature stability

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Too many pins
B	Excessive lead length
C	Unsuitable for combining analog and digital signals
D	Epoxy coating is conductive above 300 MHz

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators provide impedance matching between the control circuit and power circuit
C	Optoisolators eliminate the effects of reflected light in the control circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

31. - E7A01

Which circuit is bistable?

Select	Answer
A	An OR gate
B	A flip-flop
C	An AND gate
D	A bipolar amplifier

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	Low bandwidth
C	Low input impedance
D	High filament voltage

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a high-pass filter
B	It is a notch filter
C	It is a low-pass filter
D	It is a band-pass 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. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Mixer blanking occurs
B	Automatic limiting occurs
C	A beat frequency is generated
D	Spurious mixer products are generated

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	Varying quartz crystal characteristics emulated in digital form
C	Signals are combined in quadrature phase relationship
D	Mixing products are converted to voltages and subtracted by adder circuits

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	0.03
C	38
D	76

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a quartz crystal
B	Through link coupling
C	Through a neutralizing capacitor
D	Through a tapped coil

39. - E8A02

Which of the following is a type of analog-to-digital conversion?

Select	Answer
A	Phase reversal
B	Level shifting
C	Successive approximation
D	Harmonic regeneration

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

Select	Answer
A	Excess 3 code
B	Extended Binary Coded Decimal Interchange Code
C	Gray code
D	Binary Coded Decimal Code

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of RF harmonics
B	The generation of key clicks
C	More difficult to copy
D	Limits data speed

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	632 watts
B	63.2 watts
C	159 watts
D	252 watts

44. - E9B04

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

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

45. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The lobes become more perpendicular to the wire
C	The front-to-back ratio decreases
D	The lobes align more in the direction of the wire

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Greater structural strength
B	Higher losses
C	Improved radiation efficiency
D	Lower Q

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Double-bazooka match
B	Gamma match
C	All these choices are correct
D	Hairpin 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. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Antenna-length circles
B	Standing wave ratio circles
C	Coaxial-length circles
D	Radiation-pattern circles

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

Figure E7-3