US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operator of the packet bulletin board station
D	The control operators of all the stations in the system

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	Specific local government channels
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	All amateur service frequencies authorized to the control operator

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	A control operator must be present at the control point
B	Only Extra Class operators may be the control operator of a remote station
C	A control operator need not be present at the control point
D	Repeater and auxiliary stations may not be remotely controlled

4. - E1D01

What is the definition of the term telemetry?

Select	Answer
A	One-way transmission of measurements at a distance from the measuring instrument
B	Two-way radiotelephone transmissions in excess of 1000 feet
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	Two-way single channel transmissions of data

5. - E1E12

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

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

6. - E1F08

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

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

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

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

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Synchronization of the horizontal and vertical sync pulses
B	Transmitting a black and white test pattern
C	Turning off the scanning beam at the conclusion of a transmission
D	Turning off the scanning beam while it is traveling from right to left or from bottom to top

9. - E2C13

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

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

10. - E2D14

What is one advantage of using JT65 coding?

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

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	Selective fading has occurred
C	The mark and space signal have been inverted
D	The receiver has drifted 5 kHz from the desired receive frequency

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	1.8 MHz - 1.9 MHz
B	28 MHz - 148 MHz
C	10 MHz - 14 MHz
D	220 MHz - 450 MHz

13. - E3B05

Which amateur bands typically support long-path propagation?

Select	Answer
A	30 meters to 10 meters
B	6 meters to 2 meters
C	160 meters to 10 meters
D	160 meters to 40 meters

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	50 percent greater
B	Twice as great
C	Four times as great
D	10 percent greater

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and frequency
B	RF amplitude and frequency
C	SWR and time
D	RF amplitude and time

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

17. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The minimum discernible signal
B	The maximum detectable spectrum
C	The multiplex distortion stability
D	The meter display sensitivity

18. - E4D09

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

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

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	A DSP filter can remove the desired signal at the same time as it removes interfering signals
B	Received CW signals will appear to be modulated at the DSP clock frequency
C	Any nearby signal passing through the DSP system will overwhelm the desired signal
D	Ringing in the DSP filter will completely remove the spaces between the CW characters

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	7.12 kHz
B	23.5 kHz
C	7.12 MHz
D	23.5 MHz

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

22. - E5C17

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor, a 0.64-microhenry inductor and an 85-picofarad capacitor at 24.900 MHz?

Select	Answer
A	Point 5
B	Point 1
C	Point 8
D	Point 3

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	0.577
C	0.5
D	0.866

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

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

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	CMOS-field effect
B	Electrolytic rectifier
C	Metal-semiconductor junction
D	Thermionic emission diode

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	Input signals are stronger
C	The input switching threshold is about two times the power supply voltage
D	Larger bypass capacitors are used in CMOS circuit design

27. - E6D08

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

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally have greater initial permeability

28. - E6E06

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

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

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of electrical energy to mechanical energy
B	The conversion of voltage to current when exposed to light
C	The conversion of light to electrical energy
D	The tendency of a battery to discharge when used outside

30. - E7A10

What is a truth table?

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

31. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
B	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
C	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
D	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with wide bandwidth and shallow skirts made using quartz crystals
B	An audio filter made with four quartz crystals that resonate at 1kHz intervals
C	A power supply filter made with interlaced quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

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

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	For compatibility with transmitters using phase modulation
B	For higher efficiency
C	To reduce impulse noise reception
D	To remove third-order distortion products

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A notch filter
B	A Hilbert-transform filter
C	An adaptive filter
D	An elliptical filter

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	14
B	28
C	7
D	0.07

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Broadband noise
B	Nyquist limit noise
C	Digital conversion noise
D	Spurious signals at discrete frequencies

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Harmonic regeneration
B	Sequential sampling
C	Level shifting
D	Phase reversal

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It facilitates error detection
B	It increases security
C	It has more possible states than simple binary
D	It has more resolution than simple binary

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Low-pass filters at the transmitter output
B	Reduce keying waveform rise and fall times
C	Increase keying waveform rise and fall times
D	High-pass filters at the transmitter output

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(radiation resistance / transmission resistance) x 100 per cent
B	(effective radiated power / transmitter output) x 100 percent
C	(total resistance / radiation resistance) x 100 per cent
D	(radiation resistance / total resistance) x 100 per cent

43. - E9B05

What type of antenna pattern over real ground is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Elevation
C	Polarization
D	Azimuth

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A type of ground-plane antenna
C	A dipole one-quarter wavelength long
D	A dipole consisting of one wavelength of wire forming a very thin loop

45. - E9D04

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

Select	Answer
A	To swamp out harmonics
B	To maximize losses
C	To minimize the Q
D	To minimize losses

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
B	It makes sure the antenna has a low-angle radiation pattern
C	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
D	It allows single-band antennas to operate on other bands

47. - E9F16

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

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage lines and current chords
C	Voltage circles and current arcs
D	Resistance circles and reactance arcs

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Low loss coax transmission line is essential for good performance
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Atmospheric noise is so high that gain over a dipole is not important

50. - 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 the most powerful transmitter
C	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
D	Only commercial transmitters

Figure E5-2

Figure E7-3

Figure E7-4

Figure E9-2