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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

SelectAnswer
AYes, the displayed frequency is within the 80 meter CW band segment
BNo, U.S. stations are not permitted to use CW emissions below 3.525 MHz
CNo, one of the sidebands of the CW signal will be out of the band
DYes, the DX station initiated the contact

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

SelectAnswer
AA form FSD-15 must be submitted to the Department of the Interior
BAn Environmental Assessment must be submitted to the FCC
CA letter of intent must be filed with the National Audubon Society
DA proposal must be submitted to the National Park Service

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

SelectAnswer
AMessages intended for connection to users of the maritime satellite service
BAll of these choices are correct
CCommunications incidental to the purpose of the amateur service and remarks of a personal nature
DBusiness-related messages for non-profit organizations

4. - E1D03

What is a telecommand station in the amateur satellite service?

SelectAnswer
AAn amateur station that transmits communications to initiate, modify or terminate functions of a space station
BAn amateur station located more than 50 km above the Earth's surface
CAn amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
DAn amateur station that transmits telemetry consisting of measurements of upper atmosphere

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

SelectAnswer
AWarn the candidate that continued failure to comply will result in termination of the examination
BAllow the candidate to complete the examination, but invalidate the results
CImmediately terminate the candidate's examination
DImmediately terminate everyone's examination and close the session

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

SelectAnswer
A10 W
B1 W
C1.5 W
D1.5 kW

7. - E2A12

What is one way to predict the location of a satellite at a given time?

SelectAnswer
ABy subtracting the mean anomaly from the orbital inclination
BBy calculations using the Keplerian elements for the specified satellite
CBy adding the mean anomaly to the orbital inclination
DBy means of the Doppler data for the specified satellite

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

SelectAnswer
AChroma
BLuminance
CSpectral Intensity
DHue

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

SelectAnswer
AA standard wireless router running custom software
BA 440 MHz transceiver with a 9600 baud modem
CAn optical cable connection between the USB ports of 2 separate computers
DA 2 meter VHF transceiver with a 1200 baud modem

10. - E2D10

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

SelectAnswer
AAn APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
BAll of these choices are correct
CAn APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
DAPRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

SelectAnswer
AMFSK16
BPSK31
C170 Hz shift, 45 baud RTTY
D300-baud packet

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

SelectAnswer
AThe waves are reflected by the ionosphere and return to their source
BElectric and magnetic fields become aligned as they travel
CChanging electric and magnetic fields propagate the energy
DThe energy propagates through a medium with a high refractive index

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

SelectAnswer
AThey become phase-locked
BTheir polarization is randomly modified
CThey become elliptically polarized
DThey are bent toward the magnetic poles

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

SelectAnswer
ADetermining the radiation pattern from an array of antennas
BModeling a radio wave's path through the ionosphere
CThe process in which an electronic display presents a pattern
DEvaluating high voltage sources for X-Rays

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

SelectAnswer
AA spectrum analyzer
BA logic analyzer
CA time-domain reflectometer
DA wattmeter

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

SelectAnswer
AThe resonant frequency of the circuit
BThe bandwidth of the circuit's frequency response
CThe inductance to capacitance ratio
DThe frequency shift

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

SelectAnswer
ALoss of sensitivity
BOverload
CExcess output level
DDistortion

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

SelectAnswer
AAmplifier desensitization
BAdjacent channel interference
CNeutralization
DIntermodulation interference

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

SelectAnswer
AThe broadcast station is transmitting an over-modulated signal
BNearby corroded metal joints are mixing and re-radiating the broadcast signals
CYour station receiver IF amplifier stage is defective
DYou are receiving sky wave signals from a distant station

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

SelectAnswer
AIt has no effect on impedance matching
BMatching range is increased
CMatching bandwidth is increased
DMatching bandwidth is decreased

21. - E5B04

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

SelectAnswer
A220 seconds
B440 seconds
C110 seconds
D55 seconds

22. - E5C12

If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

SelectAnswer
AIt is equivalent to a pure resistance
BIt contains resistance and capacitive reactance
CIt contains resistance and inductive reactance
DIt has to be a direct current circuit

23. - E5D11

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

SelectAnswer
A1.414
B0.866
C1.73
D0.5

24. - 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?

SelectAnswer
AAlpha rejection frequency
BCorner frequency
CAlpha cutoff frequency
DBeta cutoff frequency

25. - E6B09

What is a common use for point contact diodes?

SelectAnswer
AAs a constant current source
BAs a constant voltage source
CAs an RF detector
DAs a high voltage rectifier

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

SelectAnswer
A4
B1
C2
D3

27. - E6D08

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

SelectAnswer
APowdered-iron cores generally have greater initial permeability
BPowdered-iron cores generally require fewer turns to produce a given inductance
CPowdered-iron cores generally maintain their characteristics at higher currents
DPowdered-iron cores use smaller diameter wire for the same inductance

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

SelectAnswer
ASurface mount
BRadial lead
CAxial lead
DTO-220

29. - E6F11

What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

SelectAnswer
A1.5 V
B0.1 V
C12 V
D0.5 V

30. - E7A07

What logical operation does a NAND gate perform?

SelectAnswer
AIt produces logic "0" at its output only when all inputs are logic "0"
BIt produces logic "1" at its output only when all inputs are logic "1"
CIt produces logic "0" at its output only when all inputs are logic "1"
DIt produces logic "0" at its output if some but not all inputs are logic "1"

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

SelectAnswer
ALess than 180 degrees
BMore than 180 degrees but less than 360 degrees
CExactly 180 degrees
DThe entire cycle

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

SelectAnswer
ASingle-Sideband voice
BVideo
CDigital
DMeteor scatter

33. - E7D07

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

SelectAnswer
AIt bypasses hum around D1
BTo provide fixed DC bias for Q1
CIt is a brute force filter for the output
DTo self-resonate at the hum frequency

34. - E7E04

What is one way a single-sideband phone signal can be generated?

SelectAnswer
ABy using a balanced modulator followed by a filter
BBy using a reactance modulator followed by a mixer
CBy using a loop modulator followed by a mixer
DBy driving a product detector with a DSB signal

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

SelectAnswer
AA phase-inverting filter
BA Hilbert-transform filter
CA crystal-lattice filter
DAn adaptive filter

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

SelectAnswer
A76
B1
C38
D0.03

37. - E7H02

Which describes a microphonic?

SelectAnswer
ADistortion caused by RF pickup on the microphone cable
BAn IC used for amplifying microphone signals
CChanges in oscillator frequency due to mechanical vibration
DExcess loading of the microphone by an oscillator

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

SelectAnswer
A8 multiplied by the gain of the input amplifier
B8
C256 divided by the gain of the input amplifier
D256

39. - 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?

SelectAnswer
A1/3
B2000
C6000
D3

40. - E8C02

What is the definition of symbol rate in a digital transmission?

SelectAnswer
AThe number of control characters in a message packet
BThe duration of each bit in a message sent over the air
CThe rate at which the waveform of a transmitted signal changes to convey information
DThe number of characters carried per second by the station-to-station link

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

SelectAnswer
A-30 dB
B+15 dB
C+10 dB
D-20 dB

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

SelectAnswer
AIt increases geometrically
BIt decreases
CIt is essentially unaffected
DIt increases arithmetically

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

SelectAnswer
AThe radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
BThey are the same
CThe total amount of radiation from the directional antenna is stronger by its front-to-back ratio
DThe total amount of radiation from the directional antenna is increased by the gain of the antenna

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

SelectAnswer
AIt reduces low-angle radiation
BIt causes increased SWR
CIt reduces losses in the radiating portion of the antenna
DIt changes the impedance angle of the matching network

45. - E9D11

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
AA single 12 gauge or 10 gauge stainless steel wire
BA cable with six or seven 18 gauge conductors in parallel
CA resistive wire, such as spark plug wire
DA wide flat copper strap

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

SelectAnswer
AThe gamma matching system
BThe stub matching system
CThe omega matching system
DThe delta matching system

47. - E9F01

What is the velocity factor of a transmission line?

SelectAnswer
AThe ratio of the characteristic impedance of the line to the terminating impedance
BThe velocity of the wave in the transmission line divided by the velocity of light in a vacuum
CThe index of shielding for coaxial cable
DThe velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

48. - E9G03

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

SelectAnswer
AImpedance and SWR values in transmission lines
BTrigonometric functions
CSatellite azimuth and elevation bearings
DBeam headings and radiation patterns

49. - 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?

SelectAnswer
AIt must be mounted more than 1 wavelength above ground
BIts overall length must not exceed 1/4 wavelength
CIt should be one or more wavelengths long
DIt should be configured as a four-sided loop

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

SelectAnswer
AHearing loss caused by high voltage corona discharge
BLocalized heating of the body from RF exposure in excess of the MPE limits
CIngestion of ozone gas from the cooling system
DBlood clotting from the intense magnetic field

Figure E6-5

Figure E7-3

Figure E7-4