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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

SelectAnswer
AReduce RFI to telephones and home entertainment systems
BLightning protection
CReduce received noise
DReduce RF current flow between pieces of equipment

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

SelectAnswer
A18.100 MHz
B18.110 MHz
C18.107 MHz
D18.068 MHz

3. - E1B02

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

SelectAnswer
A15 kHz
B10 kHz
C20 kHz
D3 kHz

4. - E1C01

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

SelectAnswer
A170 Hz
B1.5 kHz
C60 Hz
D2.8 kHz

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

SelectAnswer
AData containing personal information
BBinary control characters
CAuxiliary relay links carrying repeater audio
DTelecommand signals from a space telecommand station

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?

SelectAnswer
APhotocopy all examination documents and forward them to the FCC for processing
BAll these choices are correct
CIssue the examinee the new or upgrade license
DThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

SelectAnswer
ATo provide temporary operation while awaiting normal licensing
BTo provide for experimental amateur communications
CTo allow regular operation on Land Mobile channels
DTo provide additional spectrum for personal use

8. - E2A10

What type of satellite appears to stay in one position in the sky?

SelectAnswer
AGeostationary
BGeomagnetic
CLEO
DHEO

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

SelectAnswer
ASync frequency
BSync amplitude
CTone frequency
DTone amplitude

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

SelectAnswer
A2 meters
B33 centimeters
C30 meters
D6 meters

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

SelectAnswer
AUnnumbered Information
BAcknowledgement
CConnect
DDisconnect

12. - E2E12

How do ALE stations establish contact?

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

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

SelectAnswer
AWait 24 hours before attempting another communication on the band
BSwitch to a lower frequency HF band
CSwitch to a higher frequency HF band
DWait 90 minutes or so for the signal degradation to pass

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C08

What does the space weather term G5 mean?

SelectAnswer
AAn extreme geomagnetic storm
BWaning sunspot numbers
CModerate solar wind
DVery low solar activity

16. - E4A02

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

SelectAnswer
ASWR and frequency
BRF amplitude and time
CSWR and time
DRF amplitude and frequency

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

SelectAnswer
AWhen used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
BWhen used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
CThe full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
DWhen used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

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?

SelectAnswer
AEasier for front-end circuitry to eliminate image responses
BImproved receiver noise figure
CFewer components in the receiver
DReduced drift

19. - E4D09

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

SelectAnswer
ATo increase rejection of signals outside the desired band
BTo store often-used frequencies
CTo provide a range of AGC time constants
DTo allow selection of the optimum RF amplifier device

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

SelectAnswer
AReactive current only
BReturn current
CCommon-mode current
DDifferential-mode current

21. - E5A15

Which of the following increases Q for inductors and capacitors?

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

22. - E5B02

What letter is commonly used to represent susceptance?

SelectAnswer
AG
BX
CY
DB

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

SelectAnswer
AA negative magnitude
BA negative phase angle
CA positive phase angle
DA positive magnitude

24. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100 VAC at 4 amperes?

SelectAnswer
A50 watts
B400 watts
C80 watts
D2000 watts

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

SelectAnswer
AThey are both high impedance
BAn FET has lower input impedance
CAn FET has higher input impedance
DThey are both low impedance

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

SelectAnswer
ACharge carrier depletion
BExcessive junction temperature
CInsufficient forward voltage
DExcessive inverse voltage

27. - E6C03

What is tri-state logic?

SelectAnswer
AProprietary logic devices manufactured by Tri-State Devices
BLow-power logic devices designed to operate at 3 volts
CLogic devices that utilize ternary math
DLogic devices with 0, 1, and high-impedance output states

28. - E6D08

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

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

29. - E6E08

How is power supplied to the most common type of MMIC?

SelectAnswer
AThrough a capacitor and RF choke connected to the amplifier input lead
BMMICs require no operating bias
CThrough a resistor and/or RF choke connected to the amplifier output lead
DDirectly to the bias voltage (VCC IN) lead

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

SelectAnswer
ACopper oxide
BCadmium Sulfide
CSelenium
DSilicon

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

SelectAnswer
A1
B2
C8
D4

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 set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
BThe tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate 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. - E7C10

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

SelectAnswer
AA crystal filter
BA DSP filter
CA cavity filter
DAn L-C filter

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

SelectAnswer
AIt controls the current supplied to the load
BIt provides D1 with current
CIt provides a constant load for the voltage source
DIt provides negative feedback to improve regulation

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

SelectAnswer
AA pre-emphasis network
BA heterodyne suppressor
CA de-emphasis network
DA heterodyne enhancer

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

SelectAnswer
AAll these choices are correct
BFIR filters can delay all frequency components of the signal by the same amount
CFIR filters are easier to implement for a given set of passband rolloff requirements
DFIR filters can respond faster to impulses

37. - E7G04

What is meant by the "op-amp input offset voltage"?

SelectAnswer
AThe output voltage of the op-amp minus its input voltage
BThe difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
CThe differential input voltage needed to bring the open loop output voltage to zero
DThe potential between the amplifier input terminals of the op-amp in an open loop condition

38. - E7H11

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

SelectAnswer
ADigital conversion noise
BNyquist limit noise
CBroadband noise
DSpurious signals at discrete frequencies

39. - E8A02

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

SelectAnswer
AHarmonic regeneration
BPhase reversal
CSuccessive approximation
DLevel shifting

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?

SelectAnswer
A6000
B3
C1/3
D2000

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

SelectAnswer
AKeying speed and shape factor (rise and fall time)
BIF bandwidth and Q
CModulation index and output power
DAll these choices are correct

42. - E8D11

What is one advantage of using ASCII code for data communications?

SelectAnswer
AIt uses one character as a shift code to send numeric and special characters
BIt contains fewer information bits per character than any other code
CIt includes built-in error correction features
DIt is possible to transmit both upper and lower case text

43. - E9A09

What is antenna efficiency?

SelectAnswer
AEffective radiated power divided by transmitter output
BRadiation resistance divided by total resistance
CRadiation resistance divided by transmission resistance
DTotal resistance divided by radiation resistance

44. - E9B04

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

SelectAnswer
A3 dB
B28 dB
C38 dB
D15 dB

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

SelectAnswer
AA portable antenna erected using two push support poles
BAn end-fed folded dipole antenna
CA wideband vertical antenna constructed from precisely tapered aluminum tubing
DA center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

SelectAnswer
AStack two Yagis fed in phase to form an array with the respective elements in parallel planes
BArrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
CStack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
DArrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

47. - E9E11

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

SelectAnswer
AIt creates a low-angle radiation pattern
BIt prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
CIt allows single-band antennas to operate on other bands
DIt ensures that each driven element operates in concert with the others to create the desired antenna pattern

48. - E9F13

What impedance does a 1/4-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AVery low impedance
BThe same as the characteristic impedance of the transmission line
CThe same as the generator output impedance
DVery high impedance

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

SelectAnswer
AThe voltage axis
BThe resistance axis
CThe current axis
DThe reactance axis

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

SelectAnswer
AAll these choices are correct
BIt has a bidirectional pattern
CIt has no clearly defined null
DIt is practical for use only on VHF and higher bands

Figure E7-2

Figure E9-3