Anonymous User

Hamboozler

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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A300 kHz to 3 MHz
B30 to 300 MHz
C3 to 30 MHz
D300 to 3000 MHz

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

SelectAnswer
A100 watts PEP effective radiated power relative to the gain of a half-wave dipole
B100 watts PEP effective radiated power relative to an isotropic radiator
C50 watts PEP effective radiated power relative to an isotropic radiator
D50 watts PEP effective radiated power relative to a dipole

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. - E1C04

What is meant by IARP?

SelectAnswer
AAn international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
BAn indication of increased antenna reflected power
CA forecast of intermittent aurora radio propagation
DThe internal amateur radio practices policy of the FCC

5. - E1D02

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

SelectAnswer
AAuxiliary relay links carrying repeater audio
BTelecommand signals from a space telecommand station
CBinary control characters
DData containing personal information

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

SelectAnswer
AA sentence of up to one year in prison
BAll these choices are correct
CRevocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
DA fine of up to $1000 per occurrence

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AOnly Amateur Extra Class operators
BAny licensed amateur operator
COnly Technician, General, Advanced or Amateur Extra Class operators
DOnly General, Advanced or Amateur Extra Class operators

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

SelectAnswer
ATo upload operational software for the transponder
BTo relay messages between satellites
CTo delay download of telemetry between satellites
DTo store digital messages in the satellite for later download by other stations

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
ANarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
BSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
CA type of modulation in which one sideband is inverted
DAmplitude modulation in which one complete sideband and a portion of the other are transmitted

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

SelectAnswer
AIn the middle of each band, usually on the national calling frequency
BIn the middle of the band, usually 25 kHz above the national calling frequency
CAt the top of each band, usually in a segment reserved for contests
DIn the weak signal segment of the band, with most of the activity near the calling frequency

11. - E2D08

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

SelectAnswer
AAcknowledgement
BUnnumbered Information
CConnect
DDisconnect

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
AAMTOR
BPACTOR
CHellschreiber
DRTTY

13. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

SelectAnswer
AThe F2 layer
BThe E layer
CThe F1 layer
DThe D layer

14. - E3B07

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

SelectAnswer
AThey are bent toward the magnetic poles
BThey become elliptically polarized
CThey become phase locked
DThey become depolarized

15. - E3C11

What does VOACAP software model?

SelectAnswer
AVHF radio propagation
BHF propagation
CAC current and impedance
DAC voltage and impedance

16. - E4A03

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

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

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

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

18. - E4C04

What is the noise figure of a receiver?

SelectAnswer
AThe ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
BThe ratio in dB of the noise generated by the receiver to the theoretical minimum noise
CThe ratio of atmospheric noise to phase noise
DThe ratio of thermal noise to atmospheric noise

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

SelectAnswer
A173.35 MHz and 139.40 MHz
B146.34 MHz and 146.61 MHz
C146.10 MHz and 147.30 MHz
D146.88 MHz and 146.34 MHz

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

SelectAnswer
ARemoval of the CW signal as well as the interfering carrier
BAny nearby signal passing through the DSP system will overwhelm the desired signal
CRinging in the DSP filter will completely remove the spaces between the CW characters
DReceived CW signals will appear to be modulated at the DSP clock frequency

21. - E5A02

What is resonance in an LC or RLC circuit?

SelectAnswer
AThe frequency at which the capacitive reactance equals the inductive reactance
BThe lowest frequency that will pass current
CThe frequency at which the reactive impedance equals the resistive impedance
DThe highest frequency that will pass current

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

SelectAnswer
A14.0 degrees with the voltage leading the current
B14.0 degrees with the voltage lagging the current
C68.2 degrees with the voltage lagging the current
D68.2 degrees with the voltage leading the current

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

SelectAnswer
AFaraday grid
BMaidenhead grid
CPolar coordinates
DElliptical coordinates

24. - E5D14

What is reactive power?

SelectAnswer
APower lost because of capacitor leakage
BPower consumed in circuit Q
CWattless, nonproductive power
DPower consumed in wire resistance in an inductor

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

SelectAnswer
AIn high-power audio circuits
BIn high-current rectifier circuits
CIn very low-frequency RF circuits
DIn microwave circuits

26. - E6B06

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

SelectAnswer
AAs a rectifier in high current power supplies
BAs a variable capacitance in an automatic frequency control circuit
CAs a constant voltage reference in a power supply
DAs a VHF/UHF mixer or detector

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

SelectAnswer
A6
B5
C4
D2

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

SelectAnswer
AExcitation current
BDirect current
CMagnetizing current
DStabilizing current

29. - E6E01

Why is gallium arsenide (GaAs) useful for semiconductor devices operating at UHF and higher frequencies?

SelectAnswer
AHigher noise figures
BHigher electron mobility
CLower transconductance
DLower junction voltage drop

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 semiconductor passive delay line
CA relay using transistors to drive the relay coil
DA device that uses semiconductors to implement the functions of an electromechanical relay

31. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt switches momentarily to the opposite binary state and then returns to its original state after a set time
BIt produces a continuous square wave oscillating between 1 and 0
CIt stores one bit of data in either a 0 or 1 state
DIt maintains a constant output voltage, regardless of variations in the input voltage

32. - E7B02

What is a Class D amplifier?

SelectAnswer
AA type of amplifier that uses switching technology to achieve high efficiency
BA frequency doubling amplifier
CAn amplifier that uses drift-mode FETs for high efficiency
DA low power amplifier that uses a differential amplifier for improved linearity

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

SelectAnswer
AThe Q of Pi-networks can be controlled
BPi-networks are more stable
CPi-networks provide balanced input and output
DL-networks cannot perform impedance transformation

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

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

35. - E7E08

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

SelectAnswer
A1.414 and 0.707 times the input frequency
BTwo and four times the original frequency
CThe square root of the product of input frequencies
DThe two input frequencies along with their sum and difference frequencies

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

SelectAnswer
AA frequency synthesizer removes the unwanted sidebands
BVarying quartz crystal characteristics emulated in digital form
CMixing products are converted to voltages and subtracted by adder circuits
DSignals are combined in quadrature phase relationship

37. - E7G01

What is the typical output impedance of an op-amp?

SelectAnswer
AVery low
B1000 ohms
CVery high
D100 ohms

38. - E7H11

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

SelectAnswer
ADigital conversion noise
BBroadband noise
CSpurious signals at discrete frequencies
DNyquist limit noise

39. - E8A02

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

SelectAnswer
ALevel shifting
BPhase reversal
CHarmonic regeneration
DSuccessive approximation

40. - E8B01

What is the modulation index of an FM signal?

SelectAnswer
AThe bandwidth of the transmitted signal divided by the modulating signal frequency
BThe ratio of frequency deviation to modulating signal frequency
CThe ratio of modulating signal amplitude to frequency deviation
DThe type of modulation used by the transmitter

41. - E8C08

How does ARQ accomplish error correction?

SelectAnswer
ASpecial binary codes provide automatic correction
BIf errors are detected, a retransmission is requested
CSpecial polynomial codes provide automatic correction
DIf errors are detected, redundant data is substituted

42. - E8D05

What is the most common method of reducing key clicks?

SelectAnswer
ALow-pass filters at the transmitter output
BReduce keying waveform rise and fall times
CHigh-pass filters at the transmitter output
DIncrease keying waveform rise and fall times

43. - E9A09

What is antenna efficiency?

SelectAnswer
AEffective radiated power divided by transmitter output
BTotal resistance divided by radiation resistance
CRadiation resistance divided by transmission resistance
DRadiation resistance divided by total resistance

44. - E9B10

What is the principle of a Method of Moments analysis?

SelectAnswer
AA wire is modeled as a single sine-wave current generator
BA wire is modeled as a series of segments, each having a uniform value of current
CA wire is modeled as a series of segments, each having a distinct value of voltage across it
DA wire is modeled as a single sine-wave voltage source

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

SelectAnswer
AAdditional higher vertical angle lobes will appear
BThe low-angle radiation increases
CThe low-angle radiation decreases
DFewer vertical angle lobes will be present

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

47. - 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 omega matching system
CThe delta matching system
DThe stub matching system

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

SelectAnswer
AZero
BThe same as the characteristic impedance of the line
CA capacitive reactance
DAn inductive reactance

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

SelectAnswer
ACoaxial-length circles
BStanding wave ratio circles
CAntenna-length circles
DRadiation-pattern circles

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

SelectAnswer
AIt eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
BIt increases signal strength by providing a better match to the feed line
CIt adds capacitive loading, increasing the bandwidth of the antenna
DIt eliminates tracking errors caused by strong out-of-band signals

Figure E6-3

Figure E7-2