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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
AGround reflections and scattering make the field strength vary with location
BE field and H field radiation intensity peaks can occur at different locations
CAll these choices are correct
DThe body reacts to electromagnetic radiation from both the E and H fields

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

3. - E1B07

To what type of regulations does PRB-1 apply?

SelectAnswer
AState and local zoning
BHomeowners associations
CFAA tower height limits
DUse of wireless devices in vehicles

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

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

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

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

SelectAnswer
AIt must be capable of external RF switching between its input and output networks
BIt must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
CIt must exhibit a gain of 0 dB or less over its full output range
DIt must produce full legal output when driven by not more than 5 watts of mean RF input power

8. - E2A10

What type of satellite appears to stay in one position in the sky?

SelectAnswer
AGeostationary
BGeomagnetic
CHEO
DLEO

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

SelectAnswer
ABy scanning lines from left to right in one field and right to left in the next
BBy scanning each field from bottom to top
CBy scanning odd numbered lines in one field and even numbered lines in the next
DBy scanning two fields simultaneously

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

SelectAnswer
ARepeater contacts between U.S. club members
BSpecial event contacts between stations in the U.S.
CContacts using tactical call signs
DContacts between a U.S. station and a non-U.S. station

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

SelectAnswer
AMSK144
BJT65
COlivia
DPACTOR III

12. - E2E02

What do the letters FEC mean as they relate to digital operation?

SelectAnswer
AFatal Error Correction
BForward Error Correction
CFirst Error Correction
DFinal Error Correction

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
AFM
BRTTY
CSSB
DCW

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
CSignals travel faster along ionospheric chords
DThe MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C10

What does the 304A solar parameter measure?

SelectAnswer
AThe solar emission at 304 GHz, correlated to x-ray flare levels
BThe ratio of x-ray flux to radio flux, correlated to sunspot number
CUV emissions at 304 angstroms, correlated to the solar flux index
DThe solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

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 spectrum analyzer
DA logic analyzer

17. - E4B11

Which of the following can be measured with a vector network analyzer?

SelectAnswer
AInput impedance
BAll these choices are correct
CReflection coefficient
DOutput impedance

18. - E4C15

What is reciprocal mixing?

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

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
A146.10 MHz and 147.30 MHz
B146.88 MHz and 146.34 MHz
C173.35 MHz and 139.40 MHz
D146.34 MHz and 146.61 MHz

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

SelectAnswer
AReactive current only
BReturn current
CCommon-mode current
DDifferential-mode current

21. - E5A14

What is the resonant frequency of an RLC circuit if R is 22 ohms, L is 50 microhenries and C is 40 picofarads?

SelectAnswer
A3.56 MHz
B1.78 MHz
C44.72 MHz
D22.36 MHz

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

SelectAnswer
ACurrent leads voltage by 90 degrees
BVoltage and current are 180 degrees out of phase
CVoltage leads current by 90 degrees
DVoltage and current are in phase

23. - E5C02

How are impedances described in polar coordinates?

SelectAnswer
ABy Y and G values
BBy real and imaginary parts
CBy X and R values
DBy phase angle and magnitude

24. - E5D15

What is the power factor of an RL circuit having a 45-degree phase angle between the voltage and the current?

SelectAnswer
A0.5
B1.0
C0.866
D0.707

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

SelectAnswer
AThey are both high impedance
BAn FET has lower input impedance
CAn FET has higher input impedance
DThey are both low impedance

26. - E6B09

What is a common use for point-contact diodes?

SelectAnswer
AAs a constant voltage source
BAs an RF detector
CAs a constant current source
DAs a high-voltage rectifier

27. - E6C05

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

SelectAnswer
ADifferential output capability
BLower distortion
CLower power consumption
DImmune to damage from static discharge

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

SelectAnswer
AToroidal cores have lower Q characteristics
BToroidal cores make it easier to couple the magnetic energy into other components
CToroidal cores exhibit greater hysteresis
DToroidal cores confine most of the magnetic field within the core material

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

SelectAnswer
ALow leakage doubly insulated package
BTwo chips in each package (Dual In Package)
CPackage mounts in a direct inverted position
DA total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

SelectAnswer
ACopper oxide
BSilicon
CSelenium
DCadmium Sulfide

31. - E7A02

What is the function of a decade counter?

SelectAnswer
AIt decodes a decimal number for display on a seven-segment LED display
BIt produces 10 output pulses for every input pulse
CIt produces one output pulse for every 10 input pulses
DIt decodes a binary number for display on a seven-segment LED display

32. - E7B18

What is a characteristic of a grounded-grid amplifier?

SelectAnswer
AHigh filament voltage
BLow bandwidth
CLow input impedance
DHigh power gain

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

SelectAnswer
ANoise factor
BPhase response
CShape factor
DPassband ripple

34. - E7D14

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

SelectAnswer
ADischarge the capacitors when voltage is removed
BProvide a minimum load on the supply
CEqualize the voltage across each capacitor
DAll these choices are correct

35. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

SelectAnswer
AA beat frequency is generated
BMixer blanking occurs
CSpurious mixer products are generated
DAutomatic limiting occurs

36. - E7F08

What is the function of decimation?

SelectAnswer
AConverting data to binary code decimal form
BAttenuating the signal
CRemoving unnecessary significant digits
DReducing the effective sample rate by removing samples

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

SelectAnswer
A0.21
B94
C47
D24

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

SelectAnswer
ATaft, Pierce and negative feedback
BTaft, Hartley and Pierce
CColpitts, Hartley and Pierce
DPierce, Fenner and Beane

39. - E8A05

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

SelectAnswer
AA grid dip meter
BA D'Arsonval meter
CA true-RMS calculating meter
DAn absorption wave meter

40. - E8B10

What is frequency division multiplexing?

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

41. - E8C10

How may data rate be increased without increasing bandwidth?

SelectAnswer
AUsing a more efficient digital code
BIt is impossible
CIncreasing analog-to-digital conversion resolution
DUsing forward error correction

42. - E8D01

Why are received spread spectrum signals resistant to interference?

SelectAnswer
AThe receiver is always equipped with a digital blanker
BIf interference is detected by the receiver it will signal the transmitter to change frequencies
CThe high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
DSignals not using the spread spectrum algorithm are suppressed in the receiver

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
A159 watts
B632 watts
C63.2 watts
D252 watts

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

SelectAnswer
ACalculus differentiation with respect to physical properties
BGraphical analysis
CMethod of Moments
DMutual impedance analysis

45. - E9C05

Which of the following is a type of OCFD antenna?

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

46. - E9D12

Which of the following would provide the best RF ground for your station?

SelectAnswer
AA 50-ohm resistor connected to ground
BAn electrically short connection to 3 or 4 interconnected ground rods driven into the Earth
CAn electrically short connection to a metal water pipe
DAn electrically short connection to 3 or 4 interconnected ground rods via a series RF choke

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

SelectAnswer
AThe gamma match
BThe epsilon match
CThe delta match
DThe stub match

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
CThe same as the characteristic impedance of the transmission line
DVery high impedance

49. - E9G05

Which of the following is a common use for a Smith chart?

SelectAnswer
ADetermine the impedance of a transmission line, given the physical dimensions
BDetermine the length and position of an impedance matching stub
CDetermine the gain of an antenna given the physical and electrical parameters
DDetermine the loss/100 feet of a transmission line, given the velocity factor and conductor materials

50. - E9H04

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

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