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

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1. - E0A08

What does SAR measure?

SelectAnswer
ASynthetic Aperture Ratio of the human body
BThe rate at which RF energy is absorbed by the body
CSignal Amplification Rating
DThe rate of RF energy reflected from stationary terrain

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

SelectAnswer
A3 kHz above the lower band edge
BThe exact lower band edge
C300 Hz above the lower band edge
D1 kHz above the lower band edge

3. - 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 Historic Places?

SelectAnswer
AA letter of intent must be filed with the Environmental Protection Agency
BA proposal must be submitted to the National Park Service
CA form FSD-15 must be submitted to the Department of the Interior
DAn Environmental Assessment must be submitted to the FCC

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

SelectAnswer
A30 seconds
B3 minutes
C5 minutes
D10 minutes

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

SelectAnswer
AAny amateur station, subject to the privileges of the class of operator license held by the control operator
BAny amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
COnly those of General, Advanced or Amateur Extra Class operators
DOnly those of Amateur Extra Class operators

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

SelectAnswer
AThe FCC
BThe VEC coordinating the session
CThe VE session manager
DEach administering VE

7. - E1F10

Who may be the control operator of an auxiliary station?

SelectAnswer
AOnly Amateur Extra Class operators
BOnly Technician, General, Advanced or Amateur Extra Class operators
COnly General, Advanced or Amateur Extra Class operators
DAny licensed amateur operator

8. - E2A03

How is the signal inverted by an inverting linear transponder?

SelectAnswer
AThe signal is passed through a mixer and the difference rather than the sum is transmitted
BThe signal is passed through a non-linear filter
CThe signal is reduced to I and Q components and the Q component is filtered out
DThe signal is detected and remodulated on the reverse sideband

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

SelectAnswer
AThe vestigial sideband carries the audio information
BThe vestigial sideband contains chroma information
CVestigial sideband reduces bandwidth while allowing for simple video detector circuitry
DVestigial sideband provides high frequency emphasis to sharpen the picture

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

SelectAnswer
AThe often-prohibited practice of posting one's own call sign and frequency on a spotting network
BA manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
CThe acceptable practice of manually posting the call signs of stations on a spotting network
DAn automatic method for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D06

Which of the following describes a method of establishing EME contacts?

SelectAnswer
AHigh-speed CW identification to avoid fading
BTime synchronous transmissions alternately from each station
CJudging optimum transmission times by monitoring beacons reflected from the moon
DStoring and forwarding digital messages

12. - E2E06

What is the most common data rate used for HF packet?

SelectAnswer
A1200 baud
B300 baud
C110 baud
D48 baud

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

SelectAnswer
A100 miles to 300 miles
B1200 miles
C2500 miles
D10 miles to 50 miles

14. - E3B05

Which amateur bands typically support long-path propagation?

SelectAnswer
A160 meters to 10 meters
BOnly 160 meters to 40 meters
COnly 30 meters to 10 meters
D6 meters to 2 meters

15. - E3C11

What does VOACAP software model?

SelectAnswer
AVHF radio propagation
BAC voltage and impedance
CHF propagation
DAC current and impedance

16. - E4A05

What is the purpose of the prescaler function on a frequency counter?

SelectAnswer
AIt amplifies low-level signals for more accurate counting
BIt divides a higher frequency signal so a low-frequency counter can display the input frequency
CIt multiplies a higher frequency signal so a low-frequency counter can display the operating frequency
DIt prevents oscillation in a low-frequency counter circuit

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

SelectAnswer
A50 ohms, 75 ohms, and 90 ohms
BShort circuit, open circuit, and 50 ohms
C50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
DShort circuit, open circuit, and resonant circuit

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

SelectAnswer
AIt can affect the receiver's frequency calibration
BIt can combine with strong signals on nearby frequencies to generate interference
CIt limits the receiver's ability to receive strong signals
DIt decreases receiver third-order intercept point

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

SelectAnswer
AOscillator instability and severe audio distortion of all but the strongest received signals
BCross-modulation of the desired signal and insufficient audio power to operate the speaker
COscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
DSpurious signals caused by cross-modulation and desensitization from strong adjacent signals

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

SelectAnswer
AIgnition noise
BAll these choices are correct
CBroadband white noise
DPower line noise

21. - E5A15

Which of the following increases Q for inductors and capacitors?

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

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

SelectAnswer
A14 degrees with the voltage lagging the current
B76 degrees with the voltage leading the current
C76 degrees with the voltage lagging the current
D14 degrees with the voltage leading the current

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

SelectAnswer
ADelta
B+jX
COmega
D-jX

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

SelectAnswer
A1600 watts
B200 watts
C1000 watts
D600 watts

25. - E6A10

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

SelectAnswer
A6
B2
C4
D5

26. - E6B01

What is the most useful characteristic of a Zener diode?

SelectAnswer
AA constant voltage drop under conditions of varying current
BAn internal capacitance that varies with the applied voltage
CA negative resistance region
DA constant current drop under conditions of varying voltage

27. - E6C04

Which of the following is an advantage of BiCMOS logic?

SelectAnswer
AIts simplicity results in much less expensive devices than standard CMOS
BAll these choices are correct
CIt is immune to electrostatic damage
DIt has the high input impedance of CMOS and the low output impedance of bipolar transistors

28. - E6D12

What is inductor saturation?

SelectAnswer
AAdjacent inductors become over-coupled
BThe inductor windings are over-coupled
CThe inductor's voltage rating is exceeded causing a flashover
DThe ability of the inductor's core to store magnetic energy has been exceeded

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

SelectAnswer
ASilicon nitride
BSilicon
CGallium nitride
DSilicon dioxide

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

31. - E7A11

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

SelectAnswer
ANegative logic
BReverse Logic
CPositive Logic
DAssertive Logic

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

SelectAnswer
AReduced intermodulation products
BSignal inversion
CIncreased overall intelligibility
DSignal distortion and excessive bandwidth

33. - E7C06

What are the distinguishing features of an elliptical filter?

SelectAnswer
AGradual passband rolloff with extreme stop band ripple
BExtremely sharp cutoff with one or more notches in the stop band
CGradual passband rolloff with minimal stop band ripple
DExtremely flat response over its pass band with gradually rounded stop band corners

34. - E7D04

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

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

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

SelectAnswer
AAn automatic band-switching circuit
BAn FM generator circuit
CA circuit for filtering two closely adjacent signals
DA circuit for detecting FM signals

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

SelectAnswer
AMore taps
BHigher data rate
CDouble-precision math routines
DComplex phasor representations

37. - E7G06

What is the gain-bandwidth of an operational amplifier?

SelectAnswer
AThe frequency at which the open-loop gain of the amplifier equals one
BThe gain of the amplifier at a filter's cutoff frequency
CThe maximum frequency for a filter circuit using that type of amplifier
DThe frequency at which the amplifier's offset voltage is zero

38. - E7H13

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

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

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

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

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

SelectAnswer
AExtremely low-power contacts
BHigh-speed digital modes
CEME
DOFDM signals are not allowed on amateur bands

41. - E8C02

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

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

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

SelectAnswer
ASome types of errors can be detected
BFaster transmission rate
CThe signal can overpower interfering signals
DForeign language characters can be sent

43. - E9A13

What term describes station output, taking into account all gains and losses?

SelectAnswer
AHalf-power bandwidth
BApparent power
CEffective radiated power
DPower factor

44. - E9B08

What is the far field of an antenna?

SelectAnswer
AThe region where radiated power dissipates over a specified time period
BThe region where the shape of the antenna pattern is independent of distance
CThe region of the ionosphere where radiated power is not refracted
DThe region where radiated field strengths are constant

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

SelectAnswer
AA figure-8 broadside to the axis of the array
BCardioid
COmni-directional
DA figure-8 oriented along the axis of the array

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

SelectAnswer
AThe front-to-back ratio decreases
BThe front-to-back ratio increases
CThe SWR is reduced
DThe frequency response is widened over the whole frequency band

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

SelectAnswer
ATo transform the antenna impedance to a higher value
BTo provide a rejection notch that prevents the radiation of harmonics
CTo cancel the inductive reactance of the matching network
DTo provide DC isolation between the feed line and the antenna

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
AThe same as the generator output impedance
BVery low impedance
CVery high impedance
DThe same as the characteristic impedance of the transmission line

49. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

SelectAnswer
AImpedance axis
BPolar axis
CReactance axis
DPrime axis

50. - E9H02

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

SelectAnswer
AThey must be erected at least 1/2 wavelength above the ground to attain good directivity
BLow loss coax transmission line is essential for good performance
CAtmospheric noise is so high that gain over a dipole is not important
DAll these choices are correct

Figure E6-1

Figure E9-3