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?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Lightning protection
C	Reduce RF current flow between pieces of equipment
D	Reduce received noise

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.107 MHz
C	18.110 MHz
D	18.100 MHz

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must file an Environmental Impact Statement with the EPA before construction begins
B	You must submit engineering drawings to the FAA
C	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
D	You must obtain a construction permit from the airport zoning authority

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	The entire band
B	None
C	Only the top 3 kHz
D	Only the bottom 3 kHz

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
B	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Immediately terminate the candidate's examination
B	Immediately terminate everyone's examination and close the session
C	Warn the candidate that continued failure to comply will result in termination of the examination
D	Allow the candidate to complete the examination, but invalidate the results

7. - E1F04

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

Select	Answer
A	A line roughly parallel to and north of the border between the U.S. and Mexico
B	A line roughly parallel to and south of the border between the U.S. and Canada
C	A line roughly parallel to and west of the U.S. Atlantic coastline
D	A line roughly parallel to and east of the U.S. Pacific coastline

8. - E2A06

What are Keplerian elements?

Select	Answer
A	Encrypting codes used for spread spectrum modulation
B	Phase reversing elements in a Yagi antenna
C	Parameters that define the orbit of a satellite
D	High-emission heater filaments used in magnetron tubes

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Tone amplitude
C	Sync frequency
D	Sync amplitude

10. - E2C02

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

Select	Answer
A	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
B	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
C	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station
D	The acceptable practice of manually posting the call signs of stations on a spotting network

11. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	802.11
B	AMTOR
C	AX.25
D	PACTOR

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?

Select	Answer
A	All these choices are correct
B	Another station you are unable to hear is using the frequency
C	The protocol version you are using is not supported by the digital station
D	Your transmit frequency is incorrect

13. - E3A01

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

Select	Answer
A	12,000 miles, if the moon is visible by both stations
B	2000 miles, if the moon is at apogee
C	5000 miles, if the moon is at perigee
D	500 miles, if the moon is at perigee

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Refracted rays and reflected waves
B	Independent waves created in the ionosphere that are elliptically polarized
C	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
D	Long-path and short-path waves

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of x-ray flux to radio flux, correlated to sunspot number
B	UV emissions at 304 angstroms, correlated to the solar flux index
C	The solar emission at 304 GHz, correlated to x-ray flare levels
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

16. - E4A04

How is the compensation of an oscilloscope probe typically adjusted?

Select	Answer
A	A frequency standard is displayed and the probe is adjusted until the deflection time is accurate
B	A high frequency sine wave is displayed and the probe is adjusted for maximum amplitude
C	A DC voltage standard is displayed and the probe is adjusted until the displayed voltage is accurate
D	A square wave is displayed and the probe is adjusted until the horizontal portions of the displayed wave are as nearly flat as possible

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Output impedance
B	Input impedance
C	All these choices are correct
D	Reflection coefficient

18. - E4C02

Which of the following receiver circuits can be effective in eliminating interference from strong out-of-band signals?

Select	Answer
A	A properly adjusted product detector
B	A narrow IF filter
C	A notch filter
D	A front-end filter or pre-selector

19. - E4D11

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

Select	Answer
A	Odd-order products overload the IF filters
B	Odd-order products are an indication of poor image rejection
C	Odd-order intermodulation produces three products for every input signal within the band of interest
D	Odd-order products of two signals in the band of interest are also likely to be within the band

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	You are receiving skywave signals from a distant station
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	One or more of the broadcast stations is transmitting an over-modulated signal
D	Your station receiver IF amplifier stage is defective

21. - E5A09

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

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance divided by the resistance
D	Resistance divided by the reactance of either the inductance or capacitance

22. - E5B06

What is susceptance?

Select	Answer
A	The ratio of magnetic field to electric field
B	The magnetic impedance of a circuit
C	A measure of the efficiency of a transformer
D	The imaginary part of admittance

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	50 ohms resistance in series with 25 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms inductive reactance

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	1600 watts
B	600 watts
C	1000 watts
D	200 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?

Select	Answer
A	Corner frequency
B	Alpha rejection frequency
C	Alpha cutoff frequency
D	Beta cutoff frequency

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?

Select	Answer
A	Longer carrier retention time
B	Less forward voltage drop
C	Much higher reverse voltage breakdown
D	More constant reverse avalanche voltage

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor that ensures that an oscillator frequency does not drift
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Excitation current
B	Magnetizing current
C	Direct current
D	Stabilizing current

29. - E6E03

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

Select	Answer
A	Gallium nitride
B	Silicon nitride
C	Silicon
D	Silicon dioxide

30. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The open-circuit voltage divided by the short-circuit current under full illumination
B	The relative fraction of light that is converted to current
C	The output RF power divided by the input DC power
D	Cost per kilowatt-hour generated

31. - E7A10

What is a truth table?

Select	Answer
A	A diagram showing logic states when the digital device output is true
B	A table of logic symbols that indicate the high logic states of an op-amp
C	A table of logic symbols that indicate the logic states of an op-amp
D	A list of inputs and corresponding outputs for a digital device

32. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Select transistors with high beta
B	All these choices are correct
C	Use a resistor in series with the emitter
D	Neutralization

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A cavity filter
B	An L-C filter
C	A crystal filter
D	A DSP filter

34. - E7D08

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

Select	Answer
A	Monostable multivibrator
B	Linear voltage regulator
C	Switching voltage regulator
D	Grounded emitter amplifier

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	A heterodyne enhancer
C	A de-emphasis network
D	A pre-emphasis network

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	An elliptical filter
B	A notch filter
C	A Hilbert-transform filter
D	An adaptive filter

37. - E7G01

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

Select	Answer
A	Very high
B	100 ohms
C	1000 ohms
D	Very low

38. - E7H12

Which of the following must be done to ensure that a crystal oscillator provides the frequency specified by the crystal manufacturer?

Select	Answer
A	Bias the crystal at a specified current
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified voltage
D	Provide the crystal with a specified parallel inductance

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A grid dip meter
B	A D'Arsonval meter
C	An absorption wave meter
D	A true-RMS calculating meter

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?

Select	Answer
A	3
B	3000
C	1000
D	0.3

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Increasing analog-to-digital conversion resolution
B	Using a more efficient digital code
C	It is impossible
D	Using forward error correction

42. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of RF harmonics
C	More difficult to copy
D	The generation of key clicks

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	632 watts
B	159 watts
C	63.2 watts
D	252 watts

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region of the ionosphere where radiated power is not refracted
B	The region where the shape of the antenna pattern is independent of distance
C	The region where radiated power dissipates over a specified time period
D	The region where radiated field strengths are constant

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	A folded dipole center-fed with 300-ohm transmission line

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio decreases
C	The front-to-back ratio increases
D	The frequency response is widened over the whole frequency band

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?

Select	Answer
A	The delta matching system
B	The omega matching system
C	The stub matching system
D	The gamma matching system

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	Very low impedance
B	The same as the characteristic impedance of the line
C	The same as the output impedance of the generator
D	Very high impedance

49. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The voltage axis
C	The reactance axis
D	The current axis

50. - E9H02

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

Select	Answer
A	All these choices are correct
B	Atmospheric noise is so high that gain over a dipole is not important
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	Low loss coax transmission line is essential for good performance

Figure E7-2

Figure E9-3