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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

SelectAnswer
ALocalized heating of the body from RF exposure in excess of the MPE limits
BIngestion of ozone gas from the cooling system
CHearing loss caused by high voltage corona discharge
DBlood clotting from the intense magnetic field

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

3. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

SelectAnswer
AThe amateur station must cease operation on all frequencies below 30 MHz
BThe amateur station must cease operation
CThe amateur station must avoid transmitting during certain hours on frequencies that cause the interference
DThe amateur station must cease operation on all frequencies above 30 MHz

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

SelectAnswer
AA special endorsement must be requested from the FCC
BOperators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
COperators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
DAn environmental impact statement must be filed with the Department of the Interior

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

SelectAnswer
AAll these choices are correct
BA label with the name, address, and telephone number of the control operator
CA photocopy of the station license
DA label with the name, address, and telephone number of the station licensee

6. - E1E06

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

SelectAnswer
AEach administering VE
BThe VE session manager
CThe FCC
DThe VEC coordinating the session

7. - E1F02

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

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

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

SelectAnswer
AFrom west to east
BFrom east to west
CFrom north to south
DFrom south to north

9. - E2B03

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

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

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

SelectAnswer
AAn automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
BA manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
CThe acceptable practice of manually posting the call signs of stations on a spotting network
DThe often-prohibited practice of posting one's own call sign and frequency on a spotting network

11. - E2D08

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

SelectAnswer
AUnnumbered Information
BDisconnect
CConnect
DAcknowledgement

12. - E2E12

How do ALE stations establish contact?

SelectAnswer
AALE radios send a constant tone code to establish a frequency for future use
BALE radios monitor an internet site for the frequency they are being paged on
CALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
DALE radios activate when they hear their signal echoed by back scatter

13. - E3A13

Which of these emission modes is best for auroral propagation?

SelectAnswer
ACW
BRTTY
CSSB
DFM

14. - E3B03

What is the best time of day for transequatorial propagation?

SelectAnswer
ANoon
BLate at night
CMorning
DAfternoon or early evening

15. - E3C13

What type of polarization is best for ground-wave propagation?

SelectAnswer
AElliptical
BHorizontal
CVertical
DCircular

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

SelectAnswer
ANever use a DC-coupled probe to measure an AC circuit
BAll these choices are correct
CNever use a high-impedance probe to measure a low-impedance circuit
DKeep the signal ground connection of the probe as short as possible

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

SelectAnswer
AModulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
BModulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
CModulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer
DModulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

SelectAnswer
AFrequency discrimination
BDesensitization
CCapture effect
DCross-modulation interference

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

SelectAnswer
AOscillator instability and severe audio distortion of all but the strongest received signals
BSpurious signals caused by cross-modulation and desensitization from strong adjacent signals
CCross-modulation of the desired signal and insufficient audio power to operate the speaker
DOscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband

20. - E4E07

Which of the following can cause shielded cables to radiate or receive interference?

SelectAnswer
ALow inductance ground connections at both ends of the shield
BCommon-mode currents on the shield and conductors
CUse of braided shielding material
DTying all ground connections to a common point resulting in differential-mode currents in the shield

21. - E5A15

Which of the following increases Q for inductors and capacitors?

SelectAnswer
ALower self-resonant frequency
BLower losses
CLower reactance
DHigher self-resonant frequency

22. - E5B10

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

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

SelectAnswer
ARectangular coordinates
BFaraday grid
CElliptical coordinates
DMaidenhead grid

24. - E5D01

What is the result of skin effect?

SelectAnswer
AThermal effects on the surface of the conductor decrease the impedance
BThermal effects on the surface of the conductor increase the impedance
CAs frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
DAs frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

SelectAnswer
ATo keep the gate voltage within specifications and prevent the device from overheating
BTo reduce the chance of static damage to the gate
CTo protect the substrate from excessive voltages
DTo provide a voltage reference for the correct amount of reverse-bias gate voltage

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

SelectAnswer
AMore constant reverse avalanche voltage
BMuch higher reverse voltage breakdown
CLess forward voltage drop
DLonger carrier retention time

27. - E6C01

What is the function of hysteresis in a comparator?

SelectAnswer
ATo allow the comparator to be used with AC input signals
BTo prevent input noise from causing unstable output signals
CTo increase the sensitivity
DTo cause the output to change states continually

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
AButterworth filters
BFerrite beads
CElectrolytic capacitors
DSteel-core toroids

29. - E6E08

How is power supplied to the most common type of MMIC?

SelectAnswer
ADirectly to the bias voltage (VCC IN) lead
BThrough a capacitor and RF choke connected to the amplifier input lead
CThrough a resistor and/or RF choke connected to the amplifier output lead
DMMICs require no operating bias

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

SelectAnswer
AAn ordinary metal
BA heavy metal
CA crystalline semiconductor
DA liquid semiconductor

31. - E7A11

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

SelectAnswer
AReverse Logic
BNegative logic
CAssertive Logic
DPositive Logic

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

SelectAnswer
ASwitching amplifiers operate at higher voltages
BLinear amplifiers have high gain resulting in higher harmonic content
CSwitching amplifiers use push-pull circuits
DThe power transistor is at saturation or cutoff most of the time

33. - E7C06

What are the distinguishing features of an elliptical filter?

SelectAnswer
AGradual passband rolloff with minimal stop band ripple
BExtremely flat response over its pass band with gradually rounded stop band corners
CGradual passband rolloff with extreme stop band ripple
DExtremely sharp cutoff with one or more notches in the stop band

34. - E7D01

How does a linear electronic voltage regulator work?

SelectAnswer
AThe conduction of a control element is varied to maintain a constant output voltage
BThe control element duty cycle is proportional to the line or load conditions
CIt has a ramp voltage as its output
DIt eliminates the need for a pass transistor

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

36. - E7F07

What function is performed by a Fast Fourier Transform?

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

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
A94
B47
C24
D0.21

38. - E7H05

How is positive feedback supplied in a Pierce oscillator?

SelectAnswer
AThrough a tapped coil
BThrough a quartz crystal
CThrough link coupling
DThrough a neutralizing capacitor

39. - E8A04

What is "dither" with respect to analog-to-digital converters?

SelectAnswer
AA method of decimation by randomly skipping samples
BA small amount of noise added to the input signal to allow more precise representation of a signal over time
CAn abnormal condition where the converter cannot settle on a value to represent the signal
DAn error caused by irregular quantization step size

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. - E8C03

Why should phase-shifting of a PSK signal be done at the zero crossing of the RF signal?

SelectAnswer
ATo minimize bandwidth
BTo improve carrier suppression
CTo simplify modulation
DAll these choices are correct

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

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

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

SelectAnswer
A2.79 dB
B6.0 dB
C3.85 dB
D8.15 dB

44. - E9B04

What is the front-to-back ratio of the radiation pattern shown in Figure E92?

SelectAnswer
A15 dB
B38 dB
C28 dB
D3 dB

45. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

SelectAnswer
AOmni-directional
BCardioid
CA figure-8 broadside to the axis of the array
DA figure-8 oriented along the axis of the array

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

SelectAnswer
AThe radiation resistance increases and the capacitive reactance decreases
BThe radiation resistance decreases and the capacitive reactance increases
CThe radiation resistance decreases and the capacitive reactance decreases
DThe radiation resistance increases and the capacitive reactance increases

47. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

SelectAnswer
ATo transform the antenna impedance to a higher value
BTo provide DC isolation between the feed line and the antenna
CTo cancel the inductive reactance of the matching network
DTo provide a rejection notch that prevents the radiation of harmonics

48. - E9F01

What is the velocity factor of a transmission line?

SelectAnswer
AThe index of shielding for coaxial cable
BThe ratio of the characteristic impedance of the line to the terminating impedance
CThe velocity of the wave in the transmission line divided by the velocity of light in a vacuum
DThe velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum

49. - E9G10

What do the arcs on a Smith chart represent?

SelectAnswer
ASWR
BPoints with constant reactance
CFrequency
DPoints with constant resistance

50. - E9H06

What is the triangulation method of direction finding?

SelectAnswer
AThe geometric angles of sky waves from the source are used to determine its position
BAntenna headings from several different receiving locations are used to locate the signal source
CA fixed receiving station plots three headings to the signal source
DA fixed receiving station uses three different antennas to plot the location of the signal source