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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

SelectAnswer
AE field and H field radiation intensity peaks can occur at different locations
BAll these choices are correct
CThe body reacts to electromagnetic radiation from both the E and H fields
DGround reflections and scattering make the field strength vary with location

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

SelectAnswer
A100 watts PEP
B50 watts PEP
C1 watt EIRP
D5 watts EIRP

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

SelectAnswer
AYou may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
BYou must submit engineering drawings to the FAA
CYou must file an Environmental Impact Statement with the EPA before construction begins
DYou must obtain a construction permit from the airport zoning authority

4. - E1C01

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

SelectAnswer
A60 Hz
B2.8 kHz
C1.5 kHz
D170 Hz

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

SelectAnswer
AAny amateur station so designated by the ITU
BAny amateur station so designated by the space station licensee
CAny amateur station designated by NASA
DAll these choices are correct

6. - E1E09

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

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

7. - E1F06

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

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

8. - E2A03

How is the signal inverted by an inverting linear transponder?

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

9. - E2B05

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

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

10. - E2C07

What is the Cabrillo format?

SelectAnswer
AA standard for submission of electronic contest logs
BA method of exchanging information during a contest QSO
CThe most common set of contest rules
DThe rules of order for meetings between contest sponsors

11. - E2D08

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

SelectAnswer
ADisconnect
BAcknowledgement
CConnect
DUnnumbered Information

12. - E2E03

How is the timing of FT4 contacts organized?

SelectAnswer
AIt depends on the lunar phase
BStations take turns on alternate days
CAlternating transmissions at 7.5 second intervals
DBy exchanging ACK/NAK packets

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

SelectAnswer
AForests
BMountain ranges
CUrban areas
DBodies of water

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

SelectAnswer
AExtraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
BLong-path and short-path waves
CIndependent waves created in the ionosphere that are elliptically polarized
DRefracted rays and reflected waves

15. - E3C11

What does VOACAP software model?

SelectAnswer
AAC voltage and impedance
BHF propagation
CVHF radio propagation
DAC current and impedance

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

SelectAnswer
ALoosely couple the analyzer near the antenna base
BConnect the antenna feed line directly to the analyzer's connector
CLoosely couple the antenna and a dummy load to the analyzer
DConnect the analyzer via a high-impedance transformer to the antenna

17. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

SelectAnswer
A100 watts
B25 watts
C75 watts
D125 watts

18. - E4C04

What is the noise figure of a receiver?

SelectAnswer
AThe ratio of thermal noise to atmospheric noise
BThe ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
CThe ratio of atmospheric noise to phase noise
DThe ratio in dB of the noise generated by the receiver to the theoretical minimum 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
B146.10 MHz and 147.30 MHz
C146.88 MHz and 146.34 MHz
D146.34 MHz and 146.61 MHz

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

SelectAnswer
ANearby corroded metal joints are mixing and re-radiating the broadcast signals
BYou are receiving skywave signals from a distant station
COne or more of the broadcast stations is transmitting an over-modulated signal
DYour station receiver IF amplifier stage is defective

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

SelectAnswer
ACapacitance
BResonance
CResistance
DConductance

22. - E5B12

What is admittance?

SelectAnswer
AThe term for the gain of a field effect transistor
BThe inverse of impedance
CThe inverse of Q factor
DThe turns ratio of a transformer

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

SelectAnswer
AOn a horizontal line, offset vertically above the horizontal axis
BOn the horizontal axis
COn a line through the origin, slanted at 45 degrees
DOn the vertical axis

24. - E5D01

What is the result of skin effect?

SelectAnswer
AAs frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
BAs frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
CThermal effects on the surface of the conductor decrease the impedance
DThermal effects on the surface of the conductor increase the impedance

25. - E6A06

What is the beta of a bipolar junction transistor?

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

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

SelectAnswer
AMuch higher reverse voltage breakdown
BLess forward voltage drop
CLonger carrier retention time
DMore constant reverse avalanche voltage

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

SelectAnswer
ADifferential output capability
BLower power consumption
CImmune to damage from static discharge
DLower distortion

28. - E6D11

Which type of core material decreases inductance when inserted into a coil?

SelectAnswer
AFerrite
BPowdered iron
CCeramic
DBrass

29. - E6E07

What type of transmission line is used for connections to MMICs?

SelectAnswer
AMiniature coax
BParallel wire
CCircular waveguide
DMicrostrip

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

SelectAnswer
AOptoisolators eliminate the effects of reflected light in the control circuit
BOptoisolators provide impedance matching between the control circuit and power circuit
COptoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
DOptoisolators provide a low impedance link between a control circuit and a power circuit

31. - E7A07

What logical operation does a NAND gate perform?

SelectAnswer
AIt produces logic 0 at its output only when all inputs are logic 1
BIt produces logic 1 at its output only when all inputs are logic 1
CIt produces logic 0 at its output only when all inputs are logic 0
DIt produces logic 0 at its output if some but not all inputs are logic 1

32. - E7B11

In Figure E7-1, what is the purpose of R3?

SelectAnswer
AFixed bias
BOutput load resistor
CSelf bias
DEmitter bypass

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

SelectAnswer
AIt cancels the reactive part of the impedance and changes the resistive part to a desired value
BIt introduces transconductance to cancel the reactive part of impedance
CReactive currents are dissipated in matched resistances
DIt introduces negative resistance to cancel the resistive part of impedance

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

SelectAnswer
AProvide a minimum load on the supply
BEqualize the voltage across each capacitor
CAll these choices are correct
DDischarge the capacitors when voltage is removed

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

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

SelectAnswer
AIncoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
BIncoming RF is converted to a control voltage for a voltage controlled oscillator
CSoftware is converted from source code to object code during operation of the receiver
DA switching mixer is used to generate I and Q signals directly from the RF input

37. - E7G12

What is an operational amplifier?

SelectAnswer
AA high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
BA digital audio amplifier whose characteristics are determined by components external to the amplifier
CAn amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
DA RF amplifier used in the UHF and microwave regions

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
ATaft, Pierce and negative feedback
BPierce, Fenner and Beane
CTaft, Hartley and Pierce
DColpitts, Hartley and Pierce

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

SelectAnswer
AAn absorption wave meter
BA D'Arsonval meter
CA grid dip meter
DA true-RMS calculating meter

40. - E8B10

What is frequency division multiplexing?

SelectAnswer
AThe transmitted signal jumps from band to band at a predetermined rate
BTwo or more information streams are merged into a baseband, which then modulates the transmitter
CTwo or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
DThe transmitted signal is divided into packets of information

41. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

SelectAnswer
ATo improve carrier suppression
BTo minimize bandwidth
CAll these choices are correct
DTo simplify modulation

42. - E8D11

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

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

43. - E9A05

What is included in the total resistance of an antenna system?

SelectAnswer
ARadiation resistance plus loss resistance
BTransmission-line resistance plus radiation resistance
CRadiation resistance plus transmission resistance
DRadiation resistance plus space impedance

44. - E9B01

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

SelectAnswer
A25 degrees
B30 degrees
C75 degrees
D50 degrees

45. - E9C09

Which of the following describes a G5RV antenna?

SelectAnswer
AA phased array antenna consisting of multiple loops
BA wide band dipole using shorted coaxial cable for the radiating elements and fed with aÿ4:1 balun
CA multi-band trap antenna
DA multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

SelectAnswer
AIt is increased
BIt is unchanged if the loading coil is located at the feed point
CIt is decreased
DIt is unchanged if the loading coil is located at a voltage maximum point

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
AInsert a 1/4-wavelength piece of 75-ohm coaxial cable transmission line in series between the antenna terminals and the 50-ohm feed cable
BInsert a 1/2 wavelength piece of 300-ohm twinlead in series between the antenna terminals and the 50-ohm feed cable
CConnect a 1/2 wavelength shorted stub of 75-ohm cable in parallel with the 50-ohm cable where it attaches to the antenna
DConnect a 1/4-wavelength open stub of 300-ohm twinlead in parallel with the coaxial feed line where it connects to 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
AVery high impedance
BVery low impedance
CThe same as the characteristic impedance of the transmission line
DThe same as the generator output impedance

49. - E9G08

What is the process of normalization with regard to a Smith chart?

SelectAnswer
AReassigning prime center with regard to the reactance axis
BReassigning impedance values with regard to the prime center
CReassigning reactance values with regard to the resistance axis
DReassigning resistance values with regard to the reactance axis

50. - E9H03

What is Receiving Directivity Factor (RDF)?

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

Figure E7-1

Figure E9-1