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

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1. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

SelectAnswer
APolymorphic silicon
BPolytetrafluoroethylene
CPolychlorinated biphenyls
DPolyethylene

2. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

SelectAnswer
AAny person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
BAny person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
COnly a person with an FCC Marine Radio license grant
DOnly a person named in an amateur station license grant

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
A3 kHz
B20 kHz
C15 kHz
D10 kHz

4. - E1C10

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHz?

SelectAnswer
AAt least 63 dB below
BAt least 43 dB below
CAt least 53 dB below
DAt least 73 dB below

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

SelectAnswer
AA person who has volunteered to prepare amateur operator license examinations
BThe person who has entered into an agreement with the FCC to be the VE session manager
CAn organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
DA person who has volunteered to administer amateur operator license examinations

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

SelectAnswer
AA line roughly parallel to and south of the border between the U.S. and Canada
BA line roughly parallel to and west of the U.S. Atlantic coastline
CA line roughly parallel to and north of the border between the U.S. and Mexico
DA line roughly parallel to and east of the U.S. Pacific coastline

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 delay download of telemetry between satellites
CTo store digital messages in the satellite for later download by other stations
DTo relay messages between satellites

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

SelectAnswer
A525
B30
C60
D1080

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

11. - E2D06

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

SelectAnswer
AStoring and forwarding digital messages
BJudging optimum transmission times by monitoring beacons reflected from the moon
CTime synchronous transmissions alternately from each station
DHigh-speed CW identification to avoid fading

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

SelectAnswer
APSK31
BAMTOR
C170 Hz shift, 45 baud RTTY
D300 baud packet

13. - E3A04

What do Hepburn maps predict?

SelectAnswer
ALocations of auroral reflecting zones
BSporadic E propagation
CProbability of tropospheric propagation
DLikelihood of rain scatter along cold or warm fronts

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C15

What might be indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?

SelectAnswer
ALong-path propagation is likely
BA temperature inversion has occurred
CIncreased transequatorial propagation is likely
DA solar flare has occurred

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

SelectAnswer
AA frequency standard is displayed and the probe is adjusted until the deflection time is accurate
BA high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
CA DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
DA square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible

17. - E4B07

What do the subscripts of S parameters represent?

SelectAnswer
AThe port or ports at which measurements are made
BFrequency order of the measurements
CRelative quality of the data
DThe relative time between measurements

18. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and that uses a 455 kHz IF frequency?

SelectAnswer
A14.445 MHz
B14.755 MHz
C13.845 MHz
D15.210 MHz

19. - E4D06

What is the term for spurious signals generated by the combination of two or more signals in a non-linear device or circuit?

SelectAnswer
ANeutralization
BAmplifier desensitization
CIntermodulation
DAdjacent channel interference

20. - E4E02

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

SelectAnswer
APower line noise
BAll these choices are correct
CIgnition noise
DBroadband white noise

21. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

SelectAnswer
AHigh, as compared to the circuit resistance
BApproximately equal to circuit resistance
CApproximately equal to inductive reactance
DApproximately equal to capacitive reactance

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
A68.2 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
D14.0 degrees with the voltage leading the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

SelectAnswer
APoint 8
BPoint 7
CPoint 1
DPoint 3

24. - E5D04

Why are short connections used at microwave frequencies?

SelectAnswer
ATo reduce phase shift along the connection
BTo reduce noise figure
CTo increase compensating capacitance
DTo increase neutralizing resistance

25. - E6A03

Why does a PN-junction diode not conduct current when reverse biased?

SelectAnswer
AOnly P-type semiconductor material can conduct current
BHoles in P-type material and electrons in the N-type material are separated by the applied voltage, widening the depletion region
CExcess holes in P-type material combine with the electrons in N-type material, converting the entire diode into an insulator
DOnly N-type semiconductor material can conduct current

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

SelectAnswer
A1
B7
C6
D5

27. - E6C03

What is tri-state logic?

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

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
AReactivity
BPermeability
CResistance
DThermal impedance

29. - E6E02

Which of the following device packages is a through-hole type?

SelectAnswer
ABall grid array
BDIP
CSOT
DPLCC

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

SelectAnswer
A1.5 V
B0.1 V
C12 V
D0.5 V

31. - E7A10

What is a truth table?

SelectAnswer
AA table of logic symbols that indicate the high logic states of an op-amp
BA diagram showing logic states when the digital device output is true
CA list of inputs and corresponding outputs for a digital device
DA table of logic symbols that indicate the logic states of an op-amp

32. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

SelectAnswer
ALoad resistors
BVoltage divider bias
CSelf bias
DFeedback

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
ATwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
BA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
CAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
DTwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground

34. - E7D07

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

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

35. - E7E07

What is meant by the term "baseband" in radio communications?

SelectAnswer
AThe frequency range occupied by a message signal prior to modulation
BThe lowest frequency band that the transmitter or receiver covers
CThe basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
DThe unmodulated bandwidth of the transmitted signal

36. - E7F13

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

SelectAnswer
AProvide incremental signal delays for filter algorithms
BProvide access for debugging software
CTo reduce excess signal pressure levels
DSelect the point at which baseband signals are generated

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

SelectAnswer
AIncrease both gain and Q
BRestrict Q but increase gain
CRestrict gain but increase Q
DRestrict both gain and Q

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

SelectAnswer
ABias the crystal at a specified voltage
BProvide the crystal with a specified parallel capacitance
CProvide the crystal with a specified parallel inductance
DBias the crystal at a specified current

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

SelectAnswer
ALower the input bandwidth to increase the effective resolution
BRemove harmonics from the output caused by the discrete analog levels generated
CImprove accuracy by removing out-of-sequence codes from the input
DAll these choices are correct

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

SelectAnswer
A47
B0.47
C0.214
D2.14

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

SelectAnswer
AGray code
BBinary Coded Decimal Code
CExcess 3 code
DExtended Binary Coded Decimal Interchange Code

42. - E8D09

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

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

43. - E9A01

What is an isotropic antenna?

SelectAnswer
AA horizontally polarized antenna used to compare Yagi antennas
BA theoretical, omnidirectional antenna used as a reference for antenna gain
CA spacecraft antenna used to direct signals toward Earth
DA grounded antenna used to measure Earth conductivity

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

SelectAnswer
A30 degrees
B75 degrees
C25 degrees
D50 degrees

45. - E9C07

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

SelectAnswer
A300 ohms
B50 ohms
C450 ohms
D72 ohms

46. - E9D08

What happens as the Q of an antenna increases?

SelectAnswer
ASWR bandwidth decreases
BSWR bandwidth increases
CGain is reduced
DMore common-mode current is present on the feed line

47. - E9E10

Which of these choices is an effective way to match an antenna with a 100-ohm feed point impedance to a 50-ohm coaxial cable feed line?

SelectAnswer
AConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to the antenna
BConnect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
CInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
DInsert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable

48. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

SelectAnswer
AThe surge impedance is higher in a parallel feed line
BElectrical signals move more slowly in a coaxial cable than in air
CThe characteristic impedance is higher in a parallel feed line
DSkin effect is less pronounced in the coaxial cable

49. - E9G07

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

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

50. - E9H03

What is Receiving Directivity Factor (RDF)?

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

Figure E5-1

Figure E6-2

Figure E7-1

Figure E7-2

Figure E9-1

Figure E9-3