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US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A05

What is the maximum power output permitted on the 60 meter band?

SelectAnswer
A50 watts PEP effective radiated power relative to an isotropic radiator
B100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C50 watts PEP effective radiated power relative to a dipole
D100 watts PEP effective radiated power relative to an isotropic radiator

2. - E1B03

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

SelectAnswer
A3 miles
B30 miles
C10 miles
D1 mile

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

SelectAnswer
ARepeater and auxiliary stations may not be remotely controlled
BA control operator must be present at the control point
CA control operator need not be present at the control point
DOnly Extra Class operators may be the control operator of a remote station

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

SelectAnswer
A2 meters
B6 meters and 2 meters
C6 meters, 2 meters, and 1.25 meters
D2 meters and 1.25 meters

5. - E1E08

To which of the following examinees may a VE not administer an examination?

SelectAnswer
ARelatives of the VE as listed in the FCC rules
BAll of these choices are correct
CEmployees of the VE
DFriends of the VE

6. - E1F08

Which of the following types of amateur station communications are prohibited?

SelectAnswer
ACommunications that have a religious content
BCommunications in a language other than English
CCommunications transmitted for hire or material compensation, except as otherwise provided in the rules
DCommunications that have a political content, except as allowed by the Fairness Doctrine

7. - E2A13

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

SelectAnswer
AGeostationary
BHEO
CGeomagnetic
DLEO

8. - E2B03

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

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

9. - E2C01

Which of the following is true about contest operating?

SelectAnswer
AOperators are permitted to make contacts even if they do not submit a log
BIt is mandatory to transmit the call sign of the station being worked as part of every transmission to that station
CInterference to other amateurs is unavoidable and therefore acceptable
DEvery contest requires a signal report in the exchange

10. - E2D11

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

SelectAnswer
ARadio direction finding spectrum analysis
BPolar coordinates
CLatitude and longitude
DTime and frequency

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

SelectAnswer
ASelective fading has occurred
BThe receiver has drifted 5 kHz from the desired receive frequency
CThe mark and space signal have been inverted
DOne of the signal filters is saturated

12. - E3A07

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

SelectAnswer
AUrban areas
BMountain ranges
CForests
DBodies of water

13. - E3B12

What is the primary characteristic of chordal hop propagation?

SelectAnswer
ASignals reflected back toward the transmitting station
BPropagation away from the great circle bearing between stations
CSuccessive ionospheric reflections without an intermediate reflection from the ground
DPropagation across the geomagnetic equator

14. - E3C15

What might a sudden rise in radio background noise indicate?

SelectAnswer
AA solar flare has occurred
BIncreased transequatorial propagation likely
CLong-path propagation is occurring
DA meteor ping

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

SelectAnswer
AAll of these choices are correct
BAntenna analyzers display a time-varying representation of the modulation envelope
CAntenna analyzers do not need an external RF source
DAntenna analyzers automatically tune your antenna for resonance

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

SelectAnswer
ATemperature coefficient of the logic
BInput attenuator accuracy
CDecade divider accuracy
DTime base accuracy

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

SelectAnswer
A4.8 kHz
B1 kHz
C2.4 kHz
D4.2 kHz

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications 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 desensitization from strong adjacent signals
DCross-modulation of the desired signal and insufficient audio power to operate the speaker

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

SelectAnswer
AA loud AC hum in the audio output of your station receiver
BThe appearance of unstable modulated or unmodulated signals at specific frequencies
CA whining type noise that continually pulses off and on
DA clicking noise at intervals of a few seconds

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

SelectAnswer
AReactance of the inductance times the reactance of the capacitance
BReactance of either the inductance or capacitance times the resistance
CReactance of either the inductance or capacitance divided by the resistance
DResistance divided by the reactance of either the inductance or capacitance

21. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

SelectAnswer
A76 degrees with the voltage leading the current
B14 degrees with the voltage lagging the current
C14 degrees with the voltage leading the current
D76 degrees with the voltage lagging the current

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

SelectAnswer
AA negative phase angle
BA negative real part
CA positive real part
DA positive phase angle

23. - E5D14

What is reactive power?

SelectAnswer
APower consumed in circuit Q
BPower lost because of capacitor leakage
CWattless, nonproductive power
DPower consumed in wire resistance in an inductor

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

SelectAnswer
AN-type impurity
BInsulator impurity
CDonor impurity
DAcceptor impurity

25. - E6B01

What is the most useful characteristic of a Zener diode?

SelectAnswer
AAn internal capacitance that varies with the applied voltage
BA constant voltage drop under conditions of varying current
CA constant current drop under conditions of varying voltage
DA negative resistance region

26. - E6C04

What is the primary advantage of tri-state logic?

SelectAnswer
ALow power consumption
BHigh speed operation
CAbility to connect many device outputs to a common bus
DMore efficient arithmetic operations

27. - E6D17

Why should core saturation of a conventional impedance matching transformer be avoided?

SelectAnswer
ATemporary changes of the core permeability could result
BHarmonics and distortion could result
CMagnetic flux would increase with frequency
DRF susceptance would increase

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

SelectAnswer
AGallium nitride
BSilicon nitride
CSilicon
DSilicon dioxide

29. - E6F09

What is the efficiency of a photovoltaic cell?

SelectAnswer
AThe effective payback period
BThe output RF power divided by the input DC power
CThe open-circuit voltage divided by the short-circuit current under full illumination
DThe relative fraction of light that is converted to current

30. - E7A03

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

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

31. - E7B08

How can an RF power amplifier be neutralized?

SelectAnswer
ABy increasing the driving power
BBy reducing the driving power
CBy feeding a 180-degree out-of-phase portion of the output back to the input
DBy feeding an in-phase component of the output back to the input

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

SelectAnswer
AA notch filter
BA band-pass filter
CA Pi-network filter
DAn all-pass filter

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

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

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

SelectAnswer
AAn automatic band-switching circuit
BA circuit for detecting FM signals
CA circuit for filtering two closely adjacent signals
DAn FM generator circuit

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

SelectAnswer
AA phase-inverting filter
BA crystal-lattice filter
CA Hilbert-transform filter
DAn adaptive filter

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

SelectAnswer
A38
B1
C76
D0.03

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

SelectAnswer
AThrough a capacitive divider
BThrough link coupling
CThrough a neutralizing capacitor
DThrough a tapped coil

38. - E8A06

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

SelectAnswer
A2.5 to 1
B1 to 1
C100 to 1
D25 to 1

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

SelectAnswer
AA digital mode for narrow band, slow speed transmissions
BA bandwidth compression technique using Fourier transforms
CA frequency modulation technique which uses non-harmonically related frequencies
DA digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

SelectAnswer
AApproximately 13 Hz
BApproximately 52 Hz
CApproximately 104 Hz
DApproximately 26 Hz

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

SelectAnswer
ABinary phase-shift keying
BPhase compandored spread spectrum
CFrequency hopping
DDirect sequence

42. - E9A16

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

SelectAnswer
A300 watts
B2000 watts
C317 watts
D126 watts

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

SelectAnswer
AThe resulting design will favor radiation of harmonic energy
BGround conductivity will not be accurately modeled
CThe computed feed point impedance may be incorrect
DThe antenna will become mechanically unstable

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

SelectAnswer
AThe lobes become more perpendicular to the wire
BThe lobes align more in the direction of the wire
CThe vertical angle increases
DThe front-to-back ratio decreases

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

SelectAnswer
ATo cancel capacitive reactance
BTo lower the Q
CTo increase the SWR bandwidth
DTo lower the losses

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

SelectAnswer
AA dielectric constant greater than 1
BAn SWR greater than 1:1
CA reflection coefficient greater than 1
DAn SWR less than 1:1

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

SelectAnswer
A15 meters
B10 meters
C20 meters
D71 meters

48. - E9G01

Which of the following can be calculated using a Smith chart?

SelectAnswer
AAntenna radiation pattern
BImpedance along transmission lines
CRadiation resistance
DRadio propagation

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

SelectAnswer
AAtmospheric noise is so high that gain over a dipole is not important
BAll of these choices are correct
CLow loss coax transmission line is essential for good performance
DThey must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - E0A06

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

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

Figure E7-3

Figure E7-4