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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
AThe rate of RF energy reflected from stationary terrain
BThe rate at which RF energy is absorbed by the body
CSynthetic Aperture Ratio of the human body
DSignal Amplification Rating

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. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

SelectAnswer
AAll amateur service frequencies authorized to the control operator
BSpecific segments in the amateur service MF, HF, VHF and UHF bands
CMilitary Auxiliary Radio System (MARS) channels
DSpecific local government channels

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

SelectAnswer
AA special endorsement must be requested from the FCC
BOperators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
COperators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
DAn environmental impact statement must be filed with the Department of the Interior

5. - E1D09

Which UHF amateur bands have frequencies authorized for space stations?

SelectAnswer
A70 cm and 33 cm
B70 cm and 13 cm
C33 cm and 13 cm
D70 cm only

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
BThree VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements
CIssue the examinee the new or upgrade license
DAll these choices are correct

7. - E1F10

Who may be the control operator of an auxiliary station?

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

8. - E2A04

What is meant by the term mode? as applied to an amateur radio satellite?

SelectAnswer
AWhether the satellite is in a low earth or geostationary orbit
BWhether the satellite is in a polar or equatorial orbit
CThe satellite's orientation with respect to the Earth
DThe satellite's uplink and downlink frequency bands

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
BVestigial sideband provides high frequency emphasis to sharpen the picture
CVestigial sideband reduces bandwidth while allowing for simple video detector circuitry
DThe vestigial sideband contains chroma information

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

SelectAnswer
ASend the call sign of the DX station three times, the words this is,then your call sign three times
BSend your full call sign and grid square
CSend your full call sign once or twice
DSend only the last two letters of your call sign until you make contact

11. - E2D11

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

SelectAnswer
APolar coordinates
BTime and frequency
CLatitude and longitude
DRadio direction finding spectrum analysis

12. - E2E10

Which of these digital modes has the narrowest bandwidth?

SelectAnswer
A300-baud packet
BPSK31
CMFSK16
D170 Hz shift, 45-baud RTTY

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

SelectAnswer
AThe jet stream
BDust devil
CWind shear
DTemperature inversion

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

SelectAnswer
A20 meters
B80 meters
C10 meters
D6 meters

15. - E3C04

What does the value of Bz (B sub Z) represent?

SelectAnswer
ACritical frequency for vertical transmissions
BGeomagnetic field stability
CDirection and strength of the interplanetary magnetic field
DDuration of long-delayed echoes

16. - E4A05

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

SelectAnswer
AS22
BS21
CS12
DS11

18. - E4C15

What is reciprocal mixing?

SelectAnswer
ATwo out-of-band signals mixing to generate an in-band spurious signal
BTwo digital signals combining from alternate time slots
CIn-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
DLocal oscillator phase noise mixing with adjacent strong signals to create interference to desired signals

19. - E4D02

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

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

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

SelectAnswer
ACommon-mode currents on the shield and conductors
BTying all ground connections to a common point resulting in differential-mode currents in the shield
CLow inductance ground connections at both ends of the shield
DUse of braided shielding material

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

SelectAnswer
AFewer components are needed for the same performance
BPhase shift can become uncontrolled
CParasitic effects are minimized
DInternal voltages increase

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

SelectAnswer
AOne time constant
BAn exponential rate of one
CA time factor of one
DOne exponential period

23. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

SelectAnswer
AFar field diagram
BNear field diagram
CVenn diagram
DPhasor diagram

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
A600 watts
B1000 watts
C200 watts
D1600 watts

25. - E6A06

What is the beta of a bipolar junction transistor?

SelectAnswer
AThe change in collector current with respect to base current
BThe breakdown voltage of the base to collector junction
CThe frequency at which the current gain is reduced to 0.707
DThe switching speed

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

SelectAnswer
AExtremely high reverse breakdown voltage
BLow junction capacitance
CReverse bias controls its forward voltage drop
DAbility to dissipate large amounts of power

27. - E6C10

In Figure E6-3, what is the schematic symbol for a NOR gate?

SelectAnswer
A3
B1
C2
D4

28. - E6D07

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

SelectAnswer
AExcitation current
BStabilizing current
CDirect current
DMagnetizing current

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. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

SelectAnswer
AAn LED and a phototransistor
BA frequency modulated helium-neon laser
CA lens and a photomultiplier
DAn amplitude modulated helium-neon laser

31. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

SelectAnswer
AA flip-flop
BAn XOR gate
CA multiplexer
DAn OR gate

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
AIncreased overall intelligibility
BSignal distortion and excessive bandwidth
CReduced intermodulation products
DSignal inversion

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
BAn L-C filter
CA DSP filter
DA cavity 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 a constant load for the voltage source
CIt provides D1 with current
DIt provides negative feedback to improve regulation

35. - E7E08

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

SelectAnswer
ATwo and four times the original frequency
BThe two input frequencies along with their sum and difference frequencies
CThe square root of the product of input frequencies
D1.414 and 0.707 times the input frequency

36. - E7F13

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

SelectAnswer
ASelect the point at which baseband signals are generated
BProvide incremental signal delays for filter algorithms
CTo reduce excess signal pressure levels
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
CUndesired oscillations added to the desired signal
DA reduction in high frequency response

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

SelectAnswer
AA phase-locked loop synthesizer
BA diode-switching matrix synthesizer
CA direct digital synthesizer
DA hybrid synthesizer

39. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

SelectAnswer
A100 to 1
B25 to 1
C2.5 to 1
D1 to 1

40. - E8B11

What is digital time division multiplexing?

SelectAnswer
ATwo or more signals are quadrature modulated to increase bandwidth efficiency
BTwo or more data streams share the same channel by transmitting time of transmission as the sub-carrier
CTwo or more signals are arranged to share discrete time slots of a data transmission
DTwo or more data streams are assigned to discrete sub-carriers on an FM transmitter

41. - E8C02

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

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

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

SelectAnswer
ABaud rate
BIntermodulation Distortion (IMD)
CRepeat Request Rate (RRR)
DSignal-to-noise ratio

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

SelectAnswer
A63.2 watts
B159 watts
C252 watts
D632 watts

44. - E9B04

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

SelectAnswer
A3 dB
B28 dB
C15 dB
D38 dB

45. - E9C05

Which of the following is a type of OCFD antenna?

SelectAnswer
AA remotely tunable dipole antenna using orthogonally controlled frequency diversity
BA multiband dipole antenna using one-way circular polarization for frequency diversity
CA dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
DA folded dipole center-fed with 300-ohm transmission line

46. - E9D04

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

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

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 cancel the inductive reactance of the matching network
CTo provide a rejection notch that prevents the radiation of harmonics
DTo provide DC isolation between the feed line and the antenna

48. - E9F11

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

SelectAnswer
AThe same as the characteristic impedance of the line
BInfinite
CA capacitive reactance
DAn inductive reactance

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

SelectAnswer
AIn fractions of antenna electrical frequency
BIn fractions of transmission line electrical wavelength
CIn fractions of antenna electrical wavelength
DIn fractions of transmission line electrical frequency

50. - E9H07

Why is RF attenuation used when direction-finding?

SelectAnswer
ATo prevent receiver overload which reduces pattern nulls
BTo compensate for isotropic directivity and the antenna effect of feed lines
CTo narrow the receiver bandwidth
DTo increase receiver sensitivity

Figure E6-3

Figure E7-2