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

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1. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Uranium Hexafluoride
B	Mica
C	Beryllium Oxide
D	Zinc oxide

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?

Select	Answer
A	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit
B	Only a person named in an amateur station license grant
C	Only a person with an FCC Marine Radio license grant
D	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	Any transmitted signal that unintentionally interferes with another licensed radio station
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
D	An amateur station transmission made without the proper call sign identification

4. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	Only when transmitting RTTY or data emissions
B	Never
C	When agreed upon by the sending or receiving station
D	When approved by the National Telecommunication and Information Administration

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	Two-way transmissions in excess of 1000 feet
C	One-way transmission of measurements at a distance from the measuring instrument
D	Two-way transmissions of data

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
B	No expenses are authorized for reimbursement
C	Teaching an amateur operator license examination preparation course
D	Providing amateur operator license examination preparation training materials

7. - E1F04

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

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

8. - E2A01

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

Select	Answer
A	From east to west
B	From north to south
C	From south to north
D	From west to east

9. - E2B11

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

Select	Answer
A	To identify the SSTV mode being used
B	To identify the call sign of the station transmitting
C	To provide vertical synchronization
D	To lock the color burst oscillator in color SSTV images

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Custom code plugs for the local trunking systems
B	Acting as store-and-forward digipeaters
C	Discovery and link establishment protocols
D	Forward error correction and Viterbi codes

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	APRS
B	WSPR
C	MSK144
D	Hellschreiber

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	PSK31
B	RTTY
C	PACTOR
D	MT63

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Wind shear
B	Dust devil
C	Temperature inversion
D	The jet stream

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Only in hours of darkness
B	Only around sunset and sunrise
C	Only around sunset
D	Any time

15. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Due to the Doppler effect
B	Downward bending due to density variations in the atmosphere
C	D-region skip
D	E-region skip

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	All signals will have a DC offset
B	A false, jittery low-frequency version of the signal is displayed
C	Excessive blanking occurs, which prevents display of the signal
D	Calibration of the vertical scale is no longer valid

17. - E4B01

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

Select	Answer
A	Decade divider accuracy
B	Input attenuator accuracy
C	Temperature coefficient of the logic
D	Time base accuracy

18. - E4C11

Why can an attenuator be used to reduce receiver overload on the lower frequency HF bands with little or no impact on signal-to-noise ratio?

Select	Answer
A	The attenuator has a noise filter to suppress interference
B	Signals are attenuated separately from the noise
C	The attenuator has a low-pass filter to increase the strength of lower frequency signals
D	Atmospheric noise is generally greater than internally generated noise even after attenuation

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Lack of neutralization
B	Nonlinear circuits or devices
C	Positive feedback
D	Too little gain

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	FM signals can no longer be demodulated
B	The audio frequency bandwidth of the received signal might be compressed
C	Received audio in the speech range might have an echo effect
D	Nearby signals may appear to be excessively wide even if they meet emission standards

21. - E5A12

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	218.3 kHz
B	31.4 kHz
C	436.6 kHz
D	15.7 kHz

22. - E5B03

How is impedance in polar form converted to an equivalent admittance?

Select	Answer
A	Square the magnitude and subtract 90 degrees from the angle
B	Take the square root of the magnitude and add 180 degrees to the angle
C	Take the reciprocal of the magnitude and change the sign of the angle
D	Take the reciprocal of the angle and change the sign of the magnitude

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On a horizontal line, offset vertically above the horizontal axis
B	On the horizontal axis
C	On the vertical axis
D	On a line through the origin, slanted at 45 degrees

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	1.414
C	0.866
D	0.5

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	2
B	3
C	6
D	1

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	An internal capacitance that varies with the applied voltage
B	A constant voltage drop under conditions of varying current
C	A constant current drop under conditions of varying voltage
D	A negative resistance region

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A type of transistor whose gain can be changed by digital logic circuits
B	A logic circuit that can be modified during use
C	Programmable equipment used for testing digital logic integrated circuits
D	A programmable collection of logic gates and circuits in a single integrated circuit

28. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	The skin effect
B	Inductive kickback
C	Non-linear core hysteresis
D	Inter-turn capacitance

29. - E6E03

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

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

30. - E6F06

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

Select	Answer
A	An ordinary metal
B	A heavy metal
C	A liquid semiconductor
D	A crystalline semiconductor

31. - E7A10

What is a truth table?

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

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Signal distortion and excessive bandwidth
B	Signal inversion
C	Increased overall intelligibility
D	Reduced intermodulation products

33. - E7C08

Which of the following factors has the greatest effect on the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The relative frequencies of the individual crystals
B	The amplitude of the signals passing through the filter
C	The gain of the RF stage preceding the filter
D	The DC voltage applied to the quartz crystal

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

Select	Answer
A	It provides a constant load for the voltage source
B	It provides negative feedback to improve regulation
C	It provides D1 with current
D	It controls the current supplied to the load

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By rectification and filtering of RF signals
B	By sensing the change of reactance in the diode with respect to frequency
C	By mixing signals with noise in the transition region of the diode
D	By breakdown of the Zener voltage

36. - E7F02

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

Select	Answer
A	An adaptive filter
B	A Hilbert-transform filter
C	A phase-inverting filter
D	A crystal-lattice filter

37. - E7G08

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

Select	Answer
A	It does not vary with frequency
B	It decreases logarithmically with increasing frequency
C	It decreases linearly with increasing frequency
D	It increases linearly with increasing frequency

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

39. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all its harmonics?

Select	Answer
A	A square wave
B	A cosine wave
C	A sine wave
D	A sawtooth wave

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?

Select	Answer
A	47
B	0.214
C	0.47
D	2.14

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	5.76 kHz
C	4.8 kHz
D	9.6 kHz

42. - E8D02

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

Select	Answer
A	Direct sequence
B	Binary phase-shift keying
C	Phase compandored spread spectrum
D	Frequency hopping

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?

Select	Answer
A	Distance from the transmitter
B	Take-off angle
C	Soil conductivity
D	The standing wave ratio

44. - E9B01

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

Select	Answer
A	50 degrees
B	25 degrees
C	75 degrees
D	30 degrees

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A multiband dipole antenna using one-way circular polarization for 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 remotely tunable dipole antenna using orthogonally controlled frequency diversity
D	A folded dipole center-fed with 300-ohm transmission line

46. - E9D09

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

Select	Answer
A	To cancel capacitive reactance
B	To increase the SWR bandwidth
C	To lower the Q
D	To lower the losses

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?

Select	Answer
A	450 ohms
B	50 ohms
C	62 ohms
D	75 ohms

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

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Resistance lines and reactance chords
C	Resistance circles and reactance arcs
D	Voltage lines and current chords

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	A very sharp peak
C	A very sharp single null
D	Broadband response

Figure E6-1

Figure E7-2

Figure E9-1