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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

SelectAnswer
A300 kHz to 3 MHz
B30 to 300 MHz
C3 to 30 MHz
D300 to 3000 MHz

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

3. - E1B01

Which of the following constitutes a spurious emission?

SelectAnswer
AAn emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
BA signal transmitted to prevent its detection by any station other than the intended recipient
CAn amateur station transmission made without the proper call sign identification
DAny transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C01

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

SelectAnswer
A1.5 kHz
B2.8 kHz
C170 Hz
D60 Hz

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

SelectAnswer
A2 watts
B100 watts
C5 watts
D1 watt

6. - E1E08

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

SelectAnswer
AEmployees of the VE
BRelatives of the VE as listed in the FCC rules
CFriends of the VE
DAll these choices are correct

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

SelectAnswer
A420 MHz - 430 MHz
B222 MHz - 223 MHz
C53 MHz - 54 MHz
D440 MHz - 450 MHz

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

SelectAnswer
AUpper sideband on the uplink becomes lower sideband on the downlink, and vice versa
BDoppler shift is reduced because the uplink and downlink shifts are in opposite directions
CSignal position in the band is reversed
DAll these choices are correct

9. - E2B06

What is vestigial sideband modulation?

SelectAnswer
AAmplitude modulation in which one complete sideband and a portion of the other are transmitted
BA type of modulation in which one sideband is inverted
CSpread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
DNarrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

10. - E2C09

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

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

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

SelectAnswer
AShort transmissions with rapidly repeated call signs and signal reports
BUse of special digital modes
C15-second timed transmission sequences with stations alternating based on location
DAll these choices are correct

12. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

SelectAnswer
AAMTOR
BPACTOR
CRTTY
DHellschreiber

13. - E3A12

What is the cause of auroral activity?

SelectAnswer
AThe interaction in the F2 layer between the solar wind and the Van Allen belt
BAn extreme low-pressure area in the polar regions
CMeteor showers concentrated in the extreme northern and southern latitudes
DThe interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B12

What is the primary characteristic of chordal hop propagation?

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

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

SelectAnswer
AIt stays the same
BIt increases
CIt decreases
DIt peaks at roughly 14 MHz

16. - E4A02

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

SelectAnswer
ARF amplitude and time
BRF amplitude and frequency
CSWR and time
DSWR and frequency

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

SelectAnswer
AThere is more power going into the antenna
BThere is possibly a short to ground in the feed line
CThere is an impedance mismatch between the antenna and feed line
DThe transmitter is not properly neutralized

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
BReduced drift
CImproved receiver noise figure
DEasier for front-end circuitry to eliminate image responses

19. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

SelectAnswer
AUtilizing a Class D final amplifier
BA properly terminated circulator at the output of the repeater's transmitter
CUtilizing a Class C final amplifier
DA band-pass filter in the feed line between the transmitter and receiver

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

SelectAnswer
ASignals that appear at one IF but not another
BSignals that have a sharply peaked frequency distribution
CSignals that are constant at all IF levels
DSignals that appear across a wide bandwidth

21. - E5A15

Which of the following increases Q for inductors and capacitors?

SelectAnswer
ALower losses
BLower self-resonant frequency
CHigher self-resonant frequency
DLower reactance

22. - E5B02

What letter is commonly used to represent susceptance?

SelectAnswer
AX
BB
CG
DY

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

SelectAnswer
ADelta
B-jX
C+jX
DOmega

24. - E5D03

What is microstrip?

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

25. - E6A02

Which of the following semiconductor materials contains excess free electrons?

SelectAnswer
ABipolar
BN-type
CP-type
DInsulated gate

26. - E6B08

Which of the following is a Schottky barrier diode?

SelectAnswer
AThermionic emission diode
BElectrolytic rectifier
CPIN junction
DMetal-semiconductor junction

27. - E6C03

What is tri-state logic?

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

28. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

SelectAnswer
AElectrolytic capacitors
BButterworth filters
CSteel-core toroids
DFerrite beads

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

SelectAnswer
AShorter circuit-board traces
BComponents have less parasitic inductance and capacitance
CSmaller circuit area
DAll these choices are correct

30. - E6F01

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

SelectAnswer
AHoles
BPhotons
CProtons
DElectrons

31. - E7A11

What type of logic defines "1" as a high voltage?

SelectAnswer
AAssertive Logic
BReverse Logic
CNegative logic
DPositive Logic

32. - E7B16

What is the effect of intermodulation products in a linear power amplifier?

SelectAnswer
ALow efficiency
BCreation of parasitic oscillations
CAll these choices are correct
DTransmission of spurious signals

33. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

SelectAnswer
AA capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
BTwo inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
CAn inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
DTwo capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

34. - E7D13

What is the equation for calculating power dissipated by a series linear voltage regulator?

SelectAnswer
AInput voltage multiplied by input current
BOutput voltage multiplied by output current
CInput voltage divided by output current
DVoltage difference from input to output multiplied by output current

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

SelectAnswer
APhase comparator
BDiscriminator
CPhase detector
DProduct detector

36. - E7F07

What function is performed by a Fast Fourier Transform?

SelectAnswer
AConverting analog signals to digital form
BConverting digital signals from the time domain to the frequency domain
CConverting 8-bit data to 16-bit data
DConverting digital signals to analog form

37. - E7G03

What is the typical input impedance of an op-amp?

SelectAnswer
A100 ohms
BVery high
C1000 ohms
DVery low

38. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

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

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

SelectAnswer
AImmunity to out-of-sequence coding reduces spurious responses
BVery high speed allows digitizing high frequencies
CVery low power consumption decreases frequency drift
DAll these choices are correct

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

SelectAnswer
A2.14
B0.214
C0.47
D47

41. - E8C09

Which digital code allows only one bit to change between sequential code values?

SelectAnswer
AGray code
BBinary Coded Decimal Code
CExcess 3 code
DExtended Binary Coded Decimal Interchange Code

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

SelectAnswer
AIf interference is detected by the receiver it will signal the transmitter to change frequencies
BIf interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
CA binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
DThe frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station

43. - E9A03

What is the radiation resistance of an antenna?

SelectAnswer
AThe specific impedance of the antenna
BThe combined losses of the antenna elements and feed line
CThe resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
DThe value of a resistance that would dissipate the same amount of power as that radiated from an antenna

44. - E9B01

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

SelectAnswer
A30 degrees
B75 degrees
C25 degrees
D50 degrees

45. - E9C08

What is a folded dipole antenna?

SelectAnswer
AA type of ground-plane antenna
BA dipole configured to provide forward gain
CA half-wave dipole with an additional parallel wire connecting its two ends
DA dipole one-quarter wavelength long

46. - E9D12

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

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

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

SelectAnswer
AThe driven element resonance must be lower than the operating frequency
BThe driven element radiation resistance must be higher than the characteristic impedance of the transmission line
CThe driven element reactance must be capacitive
DThe driven element reactance must be inductive

48. - E9F11

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

SelectAnswer
AThe same as the characteristic impedance of the line
BAn inductive reactance
CA capacitive reactance
DInfinite

49. - E9G05

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

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

50. - 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
BThey must be erected at least 1/2 wavelength above the ground to attain good directivity
CAll these choices are correct
DLow loss coax transmission line is essential for good performance

Figure E9-1