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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter operating with a duty cycle greater than 50 percent
B	Only commercial transmitters
C	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
D	Only the most powerful transmitter

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
B	Only a person named in an amateur station license grant
C	Only a person with an FCC Marine Radio license grant
D	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	3 miles
B	10 miles
C	30 miles
D	1 mile

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 73 dB below
B	At least 63 dB below
C	At least 43 dB below
D	At least 53 dB below

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	33 cm and 13 cm
B	70 cm and 13 cm
C	70 cm and 33 cm
D	70 cm only

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

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
B	Communications that have religious content
C	Communications that have political content, except as allowed by the Fairness Doctrine
D	Communications in a language other than English

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From south to north
C	From east to west
D	From west to east

9. - E2B05

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

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

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 each band, usually on the national calling frequency
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	In the weak signal segment of the band, with most of the activity near the calling frequency

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	Easily copied by ear if necessary
C	The ability to decode signals which have a very low signal-to-noise ratio
D	Permits fast-scan TV transmissions over narrow bandwidth

12. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	PSK31
B	170 Hz shift, 45-baud RTTY
C	MFSK16
D	300-baud packet

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
C	An extreme low-pressure area in the polar regions
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

14. - E3B09

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

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

15. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	AC voltage and impedance
C	AC current and impedance
D	HF propagation

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	An antenna analyzer
B	An ohmmeter
C	A spectrum analyzer
D	A Q meter

17. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	Frequency order of the measurements
B	The port or ports at which measurements are made
C	The relative time between measurements
D	Relative quality of the data

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Easier for front-end circuitry to eliminate image responses
C	Reduced drift
D	Fewer components in the receiver

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
C	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals
D	Cross-modulation of the desired signal and insufficient audio power to operate the speaker

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	All these choices are correct
C	A malfunctioning illuminated advertising display
D	Arcing contacts in a thermostatically controlled device

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 voltage and current are 180 degrees out of phase
C	The voltage leads the current by 90 degrees
D	The current leads the voltage by 90 degrees

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Take the reciprocal of the angle and change the sign of the magnitude
B	Take the reciprocal of the magnitude and change the sign of the angle
C	Take the square root of the magnitude and add 180 degrees to the angle
D	Square the magnitude and subtract 90 degrees from the angle

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 7
B	Point 3
C	Point 1
D	Point 8

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

Select	Answer
A	100 watts
B	200 watts
C	141.4 watts
D	70.7 watts

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 microwave circuits
D	In high-current rectifier circuits

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a rectifier in high current power supplies
B	As a constant voltage reference in a power supply
C	As a VHF/UHF mixer or detector
D	As a variable capacitance in an automatic frequency control circuit

27. - E6C01

What is the function of hysteresis in a comparator?

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

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

Select	Answer
A	Ferrite
B	Brass
C	Ceramic
D	Powdered iron

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	Ball grid array
C	PLCC
D	DIP

30. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A digital encryption device often used to encrypt spacecraft control signals
B	A device that measures the strength of a beam of light using analog to digital conversion
C	A device for generating RTTY signals by means of a rotating light source
D	A device that detects rotation of a control by interrupting a light source with a patterned wheel

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Negative logic
B	Positive Logic
C	Reverse Logic
D	Assertive Logic

32. - E7B01

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

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

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A cavity filter
B	A DSP filter
C	An L-C filter
D	A crystal filter

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a diode bridge rectifier for increased output
C	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
D	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle

35. - E7E08

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

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

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	A switching mixer is used to generate I and Q signals directly from the RF input
B	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
C	Incoming RF is converted to a control voltage for a voltage controlled oscillator
D	Software is converted from source code to object code during operation of the receiver

37. - E7G12

What is an operational amplifier?

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

38. - E7H10

What information is contained in the lookup table of a direct digital synthesizer (DDS)?

Select	Answer
A	The phase relationship between a voltage-controlled oscillator and the output waveform
B	Amplitude values that represent the desired waveform
C	The phase relationship between a reference oscillator and the output waveform
D	Frequently used receiver and transmitter frequencies

39. - E8A07

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

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

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	2000
B	1/3
C	6000
D	3

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	IF bandwidth and Q
B	All these choices are correct
C	Keying speed and shape factor (rise and fall time)
D	Modulation index and output power

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Soil conductivity
B	Distance from the transmitter
C	Take-off angle
D	The standing wave ratio

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where radiated power dissipates over a specified time period
B	The region where radiated field strengths are constant
C	The region where the shape of the antenna pattern is independent of distance
D	The region of the ionosphere where radiated power is not refracted

45. - E9C05

Which of the following is a type of OCFD antenna?

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is decreased
B	It is increased
C	It is unchanged if the loading coil is located at a voltage maximum point
D	It is unchanged if the loading coil is located at the feed point

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Velocity factor
C	Dielectric constant
D	Characteristic impedance

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	The surge impedance is higher in a parallel feed line
B	Skin effect is less pronounced in the coaxial cable
C	The characteristic impedance is higher in a parallel feed line
D	Electrical signals move more slowly in a coaxial cable than in air

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Impedance axis
B	Reactance axis
C	Prime axis
D	Polar axis

50. - E9H07

Why is RF attenuation used when direction-finding?

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

Figure E5-1

Figure E9-3