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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

SelectAnswer
ABeryllium Oxide
BZinc oxide
CMica
DUranium Hexafluoride

2. - 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?

SelectAnswer
AThe control operators of all the stations in the system not authenticating the source from which they accept communications
BThe control operator of the packet bulletin board station
CThe control operators of all the stations in the system
DThe control operator of the originating station

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

SelectAnswer
AFile an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
BCease operation or make changes to the repeater to mitigate the interference
CReduce the repeater antenna HAAT (Height Above Average Terrain)
DAll these choices are correct

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

SelectAnswer
A2.8 kHz
B60 Hz
C1.5 kHz
D170 Hz

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

SelectAnswer
A2 watts
B1 watt
C100 watts
D5 watts

6. - E1E08

To which of the following examinees may a VE not administer an examination?

SelectAnswer
AFriends of the VE
BAll these choices are correct
CEmployees of the VE
DRelatives of the VE as listed in the FCC rules

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AAny licensed amateur operator
BOnly General, Advanced or Amateur Extra Class operators
COnly Amateur Extra Class operators
DOnly Technician, General, Advanced or Amateur Extra Class operators

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

SelectAnswer
AUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa
BDoppler shift is reduced because the uplink and downlink shifts are in opposite directions
CAll these choices are correct
DSignal position in the band is reversed

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

SelectAnswer
AA special IF converter
BNo other hardware is needed
CA special front end limiter
DA special notch filter to remove synchronization pulses

10. - E2C07

What is the Cabrillo format?

SelectAnswer
AA method of exchanging information during a contest QSO
BThe most common set of contest rules
CThe rules of order for meetings between contest sponsors
DA standard for submission of electronic contest logs

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

SelectAnswer
ALatitude and longitude
BTime and frequency
CPolar coordinates
DRadio direction finding spectrum analysis

12. - E2E12

How do ALE stations establish contact?

SelectAnswer
AALE radios send a constant tone code to establish a frequency for future use
BALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
CALE radios monitor an internet site for the frequency they are being paged on
DALE radios activate when they hear their signal echoed by back scatter

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
AFM
BCW
CSSB
DRTTY

14. - E3B10

Why is chordal hop propagation desirable?

SelectAnswer
AAtmospheric noise is lower in the direction of chordal hop propagation
BSignals travel faster along ionospheric chords
CThe signal experiences less loss compared to multi-hop using Earth as a reflector
DThe MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C09

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

SelectAnswer
A10 percent greater
B50 percent greater
CFour times as great
DTwice as great

16. - E4A01

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

SelectAnswer
AAll these choices are correct
BQ of the circuit
CAmount of memory
DSampling rate of the analog-to-digital converter

17. - 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?

SelectAnswer
AThere is possibly a short to ground in the feed line
BThe transmitter is not properly neutralized
CThere is an impedance mismatch between the antenna and feed line
DThere is more power going into the antenna

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

SelectAnswer
AA narrow IF filter
BA properly adjusted product detector
CA notch filter
DA front-end filter or pre-selector

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

SelectAnswer
AA properly terminated circulator at the output of the repeater's transmitter
BA band-pass filter in the feed line between the transmitter and receiver
CUtilizing a Class D final amplifier
DUtilizing a Class C final amplifier

20. - E4E06

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

SelectAnswer
AA whining type noise that continually pulses off and on
BThe appearance of unstable modulated or unmodulated signals at specific frequencies
CA clicking noise at intervals of a few seconds
DA loud AC hum in the audio output of your station receiver

21. - E5A15

Which of the following increases Q for inductors and capacitors?

SelectAnswer
ALower self-resonant frequency
BHigher self-resonant frequency
CLower reactance
DLower losses

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

SelectAnswer
AVoltage and current are in phase
BVoltage and current are 180 degrees out of phase
CVoltage leads current by 90 degrees
DCurrent leads voltage by 90 degrees

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

SelectAnswer
AThe X axis represents the resistive component and the Y axis represents the reactive component
BThe X axis represents the magnitude and the Y axis represents the phase angle
CThe X axis represents the phase angle and the Y axis represents the magnitude
DThe X axis represents the reactive component and the Y axis represents the resistive component

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

SelectAnswer
AIt is dissipated as kinetic energy in the circuit
BIt is dissipated as heat in the circuit
CIt is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
DIt is dissipated in the formation of inductive and capacitive fields

25. - E6A10

In Figure E6-1, what is the schematic symbol for an N-channel dual-gate MOSFET?

SelectAnswer
A5
B6
C4
D2

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

SelectAnswer
ACapacitance of an RF coupling capacitor
BReverse voltage larger than the RF signal
CA sub-harmonic pump signal
DForward DC bias current

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

SelectAnswer
A2
B1
C3
D4

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

SelectAnswer
AToroidal cores have lower Q characteristics
BToroidal cores confine most of the magnetic field within the core material
CToroidal cores make it easier to couple the magnetic energy into other components
DToroidal cores exhibit greater hysteresis

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

SelectAnswer
APackage mounts in a direct inverted position
BA total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
CLow leakage doubly insulated package
DTwo chips in each package (Dual In Package)

30. - E6F07

What is a solid-state relay?

SelectAnswer
AA mechanical relay that latches in the on or off state each time it is pulsed
BA device that uses semiconductors to implement the functions of an electromechanical relay
CA relay using transistors to drive the relay coil
DA semiconductor passive delay line

31. - E7A11

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

SelectAnswer
APositive Logic
BAssertive Logic
CNegative logic
DReverse Logic

32. - 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?

SelectAnswer
AThe tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current
BThe tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
CThe loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
DThe loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

SelectAnswer
ANoise factor
BPassband ripple
CPhase response
DShape factor

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

SelectAnswer
AA series regulator
BA series current source
CA shunt regulator
DA shunt current source

35. - E7E04

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

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

36. - E7F13

What is the function of taps in a digital signal processing filter?

SelectAnswer
ATo reduce excess signal pressure levels
BProvide incremental signal delays for filter algorithms
CSelect the point at which baseband signals are generated
DProvide access for debugging software

37. - E7G02

What is ringing in a filter?

SelectAnswer
APartial cancellation of the signal over a range of frequencies
BAn echo caused by a long time delay
CA reduction in high frequency response
DUndesired oscillations added to the desired signal

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

SelectAnswer
AAll these choices are correct
BUse a temperature-controlled high Q dielectric resonator
CUse a rubidium stabilized reference oscillator
DUse a GPS signal reference

39. - E8A07

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

SelectAnswer
AThe degree of carrier suppression
BThe frequency of the modulating signal
CAmplifier gain
DSpeech characteristics

40. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

SelectAnswer
A0.6
B60
C1.67
D0.167

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
AThey are the same
BSymbol rate is only used for packet-based modes
CBaud is twice the symbol rate
DBaud is only used for RTTY

42. - E8D09

What is considered an acceptable maximum IMD level for an idling PSK signal?

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

43. - E9A05

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

SelectAnswer
ARadiation resistance plus transmission resistance
BRadiation resistance plus loss resistance
CRadiation resistance plus space impedance
DTransmission-line resistance plus radiation resistance

44. - E9B07

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

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

45. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

SelectAnswer
A50 ohms
B72 ohms
C450 ohms
D300 ohms

46. - E9D04

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

SelectAnswer
ATo lower the radiation angle
BTo minimize the Q
CTo swamp out harmonics
DTo minimize losses

47. - E9E09

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

SelectAnswer
AHairpin match
BDouble-bazooka match
CAll these choices are correct
DGamma match

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

SelectAnswer
A5.2 meters
B6.9 meters
C10.4 meters
D8.3 meters

49. - E9G10

What do the arcs on a Smith chart represent?

SelectAnswer
AFrequency
BSWR
CPoints with constant reactance
DPoints with constant resistance

50. - E9H03

What is Receiving Directivity Factor (RDF)?

SelectAnswer
ARelative directivity compared to a dipole
BRelative directivity compared to isotropic
CForward gain compared to the gain in the reverse direction
DForward gain compared to average gain over the entire hemisphere

Figure E6-1

Figure E6-3