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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

SelectAnswer
ALightning protection
BReduce received noise
CReduce RFI to telephones and home entertainment systems
DReduce RF current flow between pieces of equipment

2. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

SelectAnswer
A1 kHz above the lower band edge
BThe exact lower band edge
C300 Hz above the lower band edge
D3 kHz above the lower band edge

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

SelectAnswer
AA form FSD-15 must be submitted to the Department of the Interior
BAn Environmental Assessment must be submitted to the FCC
CA letter of intent must be filed with the Environmental Protection Agency
DA proposal must be submitted to the National Park Service

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

SelectAnswer
A2.0
B0.5
C1.0
D3.0

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E06

Who is responsible for the proper conduct and necessary supervision during an amateur operator license examination session?

SelectAnswer
AThe FCC
BThe VE session manager
CThe VEC coordinating the session
DEach administering VE

7. - E1F04

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

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

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

SelectAnswer
ATo prevent creating errors in the satellite telemetry
BTo prevent the satellite from emitting out-of-band signals
CTo avoid interfering with terrestrial QSOs
DTo avoid reducing the downlink power to all other users

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

SelectAnswer
ATo identify the call sign of the station transmitting
BTo provide vertical synchronization
CTo identify the SSTV mode being used
DTo lock the color burst oscillator in color SSTV images

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

SelectAnswer
AA 2 meter VHF transceiver with a 1200 baud modem
BA wireless router running custom firmware
CA 440 MHz transceiver with a 9600 baud modem
DAn optical cable connection between the USB ports of 2 separate computers

11. - E2D08

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

SelectAnswer
AAcknowledgement
BConnect
CDisconnect
DUnnumbered Information

12. - E2E07

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

SelectAnswer
AYour transmit frequency is incorrect
BAll these choices are correct
CThe protocol version you are using is not supported by the digital station
DAnother station you are unable to hear is using the frequency

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

SelectAnswer
ASprites and jets
BWarm and cold fronts
CLightning discharges
DGrayline

14. - E3B03

What is the best time of day for transequatorial propagation?

SelectAnswer
AAfternoon or early evening
BNoon
CMorning
DLate at night

15. - E3C01

What does the radio communication term "ray tracing" describe?

SelectAnswer
ADetermining the radiation pattern from an array of antennas
BThe process in which an electronic display presents a pattern
CEvaluating high voltage sources for x-rays
DModeling a radio wave's path through the ionosphere

16. - E4A02

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

SelectAnswer
ASWR and time
BRF amplitude and frequency
CRF amplitude and time
DSWR and frequency

17. - E4B07

What do the subscripts of S parameters represent?

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

18. - E4C07

What does the MDS of a receiver represent?

SelectAnswer
AThe minimum discernible signal
BThe multiplex distortion stability
CThe meter display sensitivity
DThe maximum detectable spectrum

19. - E4D08

What causes intermodulation in an electronic circuit?

SelectAnswer
AToo little gain
BNonlinear circuits or devices
CPositive feedback
DLack of neutralization

20. - E4E02

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

SelectAnswer
AAll these choices are correct
BBroadband white noise
CPower line noise
DIgnition noise

21. - E5A13

What is an effect of increasing Q in a series resonant circuit?

SelectAnswer
APhase shift can become uncontrolled
BParasitic effects are minimized
CFewer components are needed for the same performance
DInternal voltages increase

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 leads current by 90 degrees
CVoltage and current are 180 degrees out of phase
DVoltage and current are in phase

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

SelectAnswer
APoint 8
BPoint 3
CPoint 7
DPoint 1

24. - E5D13

How many watts are consumed in a circuit consisting of a 100-ohm resistor in series with a 100-ohm inductive reactance drawing 1 ampere?

SelectAnswer
A141.4 watts
B100 watts
C200 watts
D70.7 watts

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

SelectAnswer
AAlpha cutoff frequency
BBeta cutoff frequency
CCorner frequency
DAlpha rejection frequency

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

SelectAnswer
AExcessive inverse voltage
BExcessive junction temperature
CInsufficient forward voltage
DCharge carrier depletion

27. - E6C03

What is tri-state logic?

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

28. - E6D06

What core material property determines the inductance of an inductor?

SelectAnswer
AResistance
BPermeability
CReactivity
DThermal impedance

29. - E6E07

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

SelectAnswer
AMiniature coax
BMicrostrip
CParallel wire
DCircular waveguide

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

SelectAnswer
AIt increases
BIt decreases
CIt stays the same
DIt becomes unstable

31. - E7A06

What is a characteristic of a monostable multivibrator?

SelectAnswer
AIt stores one bit of data in either a 0 or 1 state
BIt produces a continuous square wave oscillating between 1 and 0
CIt maintains a constant output voltage, regardless of variations in the input voltage
DIt switches momentarily to the opposite binary state and then returns to its original state after a set time

32. - E7B13

Which of the following describes an emitter follower (or common collector) amplifier?

SelectAnswer
AA two-transistor amplifier with the emitters sharing a common bias resistor
BA differential amplifier with both inputs fed to the emitter of the input transistor
CAn OR circuit with only one emitter used for output
DAn amplifier with a low impedance output that follows the base input voltage

33. - E7C04

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

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

34. - E7D08

What type of circuit is shown in Figure E7-2?

SelectAnswer
AMonostable multivibrator
BSwitching voltage regulator
CGrounded emitter amplifier
DLinear voltage regulator

35. - E7E07

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

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

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

SelectAnswer
AHigher data rate
BDouble-precision math routines
CMore taps
DComplex phasor representations

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

SelectAnswer
AIt increases linearly with increasing frequency
BIt decreases logarithmically with increasing frequency
CIt decreases linearly with increasing frequency
DIt does not vary with frequency

38. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

SelectAnswer
ANP0 capacitors
BToroidal inductors
CNon-inductive resistors
DWirewound resistors

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

SelectAnswer
APeak envelope power
BTotal harmonic distortion
CPower factor
DReciprocal mixing

40. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

SelectAnswer
A1000
B3000
C3
D0.3

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

SelectAnswer
A104 Hz
B52 Hz
C26 Hz
D13 Hz

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

SelectAnswer
ABaudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
BBaudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
CBaudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
DBaudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

SelectAnswer
ASoil conductivity
BThe standing wave ratio
CDistance from the transmitter
DTake-off angle

44. - E9B09

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

SelectAnswer
AGraphical analysis
BMutual impedance analysis
CMethod of Moments
DCalculus differentiation with respect to physical properties

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

SelectAnswer
AIt changes the radiation pattern from bidirectional to unidirectional
BIt changes the radiation pattern from horizontal to vertical polarization
CIt decreases the ground loss
DIt reflects the standing waves on the antenna elements back to the transmitter

46. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

SelectAnswer
ATo swamp out harmonics
BTo minimize losses
CTo minimize the Q
DTo lower the radiation angle

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

SelectAnswer
A75 ohms
B62 ohms
C50 ohms
D450 ohms

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

SelectAnswer
AThe line length
BThe termination impedance
CDielectric materials used in the line
DThe center conductor resistivity

49. - E9G05

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

SelectAnswer
ADetermine the length and position of an impedance matching stub
BDetermine the impedance of a transmission line, given the physical dimensions
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. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

SelectAnswer
AIt should be configured as a four-sided loop
BIt should be one or more wavelengths long
CIt must be mounted more than 1 wavelength above ground
DIts overall length must not exceed 1/4 wavelength

Figure E5-1

Figure E7-2