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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

SelectAnswer
AOnly commercial transmitters
BEach transmitter operating with a duty cycle greater than 50 percent
CEach transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
DOnly the most powerful transmitter

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

SelectAnswer
AThe amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
BThe amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
CThe amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
DIts operation must be approved by the master of the ship or the pilot in command of the aircraft

3. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

SelectAnswer
A3 miles
B10 miles
C1 mile
D30 miles

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

5. - E1D02

Which of the following may transmit special codes intended to obscure the meaning of messages?

SelectAnswer
AAuxiliary relay links carrying repeater audio
BBinary control characters
CData containing personal information
DTelecommand signals from a space telecommand station

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

SelectAnswer
AThe VEs
BThe FCC
CThe VECs
DThe ARRL

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

SelectAnswer
AThe operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
BFull privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
CNone, they must obtain a U.S. license
DAll privileges of the Amateur Extra Class license

8. - E2A05

What do the letters in a satellite's mode designator specify?

SelectAnswer
AThe polarization of uplink and downlink signals
BThe location of the ground control station
CPower limits for uplink and downlink transmissions
DThe uplink and downlink frequency ranges

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

SelectAnswer
AA special IF converter
BNo other hardware is needed
CA special notch filter to remove synchronization pulses
DA special front end limiter

10. - E2C04

Which of the following frequencies are sometimes used for amateur radio mesh networks?

SelectAnswer
AHF frequencies where digital communications are permitted
BCable TV channels 41 through 43
CFrequencies shared with various unlicensed wireless data services
DThe 60 meter band channel centered on 5373 kHz

11. - E2D05

What is one advantage of the JT65 mode?

SelectAnswer
AThe ability to decode signals which have a very low signal-to-noise ratio
BUses only a 65 Hz bandwidth
CPermits fast-scan TV transmissions over narrow bandwidth
DEasily copied by ear if necessary

12. - E2E10

Which of these digital modes has the narrowest bandwidth?

SelectAnswer
AMFSK16
BPSK31
C300-baud packet
D170 Hz shift, 45-baud RTTY

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

SelectAnswer
A5000 miles, if the moon is at perigee
B12,000 miles, if the moon is visible by both stations
C500 miles, if the moon is at perigee
D2000 miles, if the moon is at apogee

14. - E3B01

What is transequatorial propagation?

SelectAnswer
APropagation between points located on the magnetic equator
BPropagation between points at the same latitude
CPropagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
DPropagation between a point on the equator and its antipodal point

15. - E3C10

What does the 304A solar parameter measure?

SelectAnswer
AThe ratio of x-ray flux to radio flux, correlated to sunspot number
BThe solar emission at 304 GHz, correlated to x-ray flare levels
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. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

SelectAnswer
ARF amplitude and time
BSWR and time
CSWR and frequency
DRF amplitude and frequency

17. - E4B05

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

SelectAnswer
A50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
BShort circuit, open circuit, and 50 ohms
CShort circuit, open circuit, and resonant circuit
D50 ohms, 75 ohms, and 90 ohms

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

SelectAnswer
AFewer components in the receiver
BEasier for front-end circuitry to eliminate image responses
CReduced drift
DImproved receiver noise figure

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

SelectAnswer
AOdd-order products of two signals in the band of interest are also likely to be within the band
BOdd-order products are an indication of poor image rejection
COdd-order products overload the IF filters
DOdd-order intermodulation produces three products for every input signal within the band of interest

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

SelectAnswer
ABy installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
BBy installing a noise suppression resistor and a blocking capacitor in both leads
CBy installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
DBy connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

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
BConductance
CResonance
DResistance

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

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 1
BPoint 7
CPoint 3
DPoint 8

24. - E5D03

What is microstrip?

SelectAnswer
ALightweight transmission line made of common zip cord
BMiniature coax used for low power applications
CPrecision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
DShort lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

SelectAnswer
AIn microwave circuits
BIn very low-frequency RF circuits
CIn high-power audio circuits
DIn high-current rectifier circuits

26. - E6B06

Which of the following is a common use of a Schottky diode?

SelectAnswer
AAs a variable capacitance in an automatic frequency control circuit
BAs a VHF/UHF mixer or detector
CAs a constant voltage reference in a power supply
DAs a rectifier in high current power supplies

27. - E6C05

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

SelectAnswer
ALower distortion
BLower power consumption
CDifferential output capability
DImmune to damage from static discharge

28. - E6D08

What is one reason for using powdered-iron cores rather than ferrite cores in an inductor?

SelectAnswer
APowdered-iron cores generally have greater initial permeability
BPowdered-iron cores generally maintain their characteristics at higher currents
CPowdered-iron cores generally require fewer turns to produce a given inductance
DPowdered-iron cores use smaller diameter wire for the same inductance

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

SelectAnswer
AAxial lead
BTO-220
CSurface mount
DRadial lead

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

SelectAnswer
APhotons
BElectrons
CHoles
DProtons

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

SelectAnswer
AIt produces logic 0 at its output only if all inputs are logic 0
BIt produces logic 0 at its output if only one input is logic 1
CIt produces logic 1 at its output if only one input is logic 1
DIt produces logic 1 at its output only if all inputs are logic 1

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

SelectAnswer
ABecause they are relatively close in frequency to the desired signal
BBecause they maintain the sidebands, thus causing multiple duplicate signals
CBecause they invert the sidebands causing distortion
DBecause they are relatively far in frequency from the desired signal

33. - E7C09

What is a crystal lattice filter?

SelectAnswer
AAn audio filter made with four quartz crystals that resonate at 1 kHz intervals
BA power supply filter made with interlaced quartz crystals
CA filter using lattice-shaped quartz crystals for high-Q performance
DA filter with narrow bandwidth and steep skirts made using quartz crystals

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

SelectAnswer
AMaximum that the output voltage may decrease at rated load
BMinimum input voltage for rated power dissipation
CMaximum output voltage drops when the input voltage is varied over its specified range
DMinimum input-to-output voltage required to maintain regulation

35. - E7E08

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

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

36. - E7F13

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

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

37. - E7G12

What is an operational amplifier?

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

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 rubidium stabilized reference oscillator
BUse a GPS signal reference
CUse a temperature-controlled high Q dielectric resonator
DAll these choices are correct

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

SelectAnswer
ASpeech characteristics
BAmplifier gain
CThe degree of carrier suppression
DThe frequency of the modulating signal

40. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

SelectAnswer
A2000
B6000
C3
D1/3

41. - E8C11

What is the relationship between symbol rate and baud?

SelectAnswer
AThey are the same
BBaud is twice the symbol rate
CSymbol rate is only used for packet-based modes
DBaud is only used for RTTY

42. - E8D06

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

SelectAnswer
AFaster transmission rate
BSome types of errors can be detected
CForeign language characters can be sent
DThe signal can overpower interfering signals

43. - E9A05

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

SelectAnswer
ARadiation resistance plus space impedance
BRadiation resistance plus loss resistance
CRadiation resistance plus transmission resistance
DTransmission-line resistance plus radiation resistance

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

SelectAnswer
A45 degrees
B75 degrees
C7.5 degrees
D25 degrees

45. - E9C07

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

SelectAnswer
A50 ohms
B72 ohms
C300 ohms
D450 ohms

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

SelectAnswer
AResistive wire, such as spark plug wire
BWide flat copper strap
CSolid wire
DStranded wire

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

SelectAnswer
AThe stub matching system
BThe delta matching system
CThe gamma matching system
DThe omega matching system

48. - E9F10

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

SelectAnswer
AZero
BAn inductive reactance
CA capacitive reactance
DThe same as the characteristic impedance of the line

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H07

Why is RF attenuation used when direction-finding?

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

Figure E5-1

Figure E9-2