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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	Microwaves often travel long distances by ionospheric reflection
B	The extremely high frequency energy can damage the joints of antenna structures
C	Microwaves are ionizing radiation
D	The high gain antennas commonly used can result in high exposure levels

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any FCC-issued amateur license
B	Only General Class or higher amateur licenses
C	An unrestricted Radiotelephone Operator Permit
D	Any amateur license with an FCC Marine or Aircraft endorsement

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?

Select	Answer
A	The amateur station must cease operation on all frequencies below 30 MHz
B	The amateur station must cease operation on all frequencies above 30 MHz
C	The amateur station must cease operation
D	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference

4. - E1C04

What is meant by IARP?

Select	Answer
A	The internal amateur radio practices policy of the FCC
B	An indication of increased antenna reflected power
C	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
D	A forecast of intermittent aurora radio propagation

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 that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth
D	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	A sentence of up to one year in prison
B	All these choices are correct
C	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
D	A fine of up to $1000 per occurrence

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When the control operator is employed by the FCC or another government agency
C	When transmitting international third-party communications
D	When neither the amateur nor his or her employer has a pecuniary interest in the communications

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. - E2B03

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

Select	Answer
A	By scanning odd numbered lines in one field and even numbered lines in the next
B	By scanning each field from bottom to top
C	By scanning two fields simultaneously
D	By 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?

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

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Polar coordinates
B	Time and frequency
C	Radio direction finding spectrum analysis
D	Latitude and longitude

12. - E2E05

Which of these digital modes does not support keyboard-to-keyboard operation?

Select	Answer
A	PSK31
B	PACTOR
C	RTTY
D	MFSK

13. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Locations of auroral reflecting zones
C	Likelihood of rain scatter along cold or warm fronts
D	Sporadic E propagation

14. - E3B07

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become depolarized
C	They become elliptically polarized
D	They become phase locked

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	10 percent greater
B	Twice as great
C	Four times as great
D	50 percent greater

16. - E4A06

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

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

17. - E4B11

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

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

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The multiplex distortion stability
B	The meter display sensitivity
C	The maximum detectable spectrum
D	The minimum discernible signal

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
D	Signals less than 40 dBm will not generate audible third-order intermodulation products

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

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	157.8 Hz
B	315.6 Hz
C	47.3 kHz
D	23.67 kHz

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage lagging the current

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 8
B	Point 1
C	Point 3
D	Point 7

24. - E5D09

What happens to reactive power in an AC circuit that has both ideal inductors and ideal capacitors?

Select	Answer
A	It is repeatedly exchanged between the associated magnetic and electric fields, but is not dissipated
B	It is dissipated in the formation of inductive and capacitive fields
C	It is dissipated as kinetic energy in the circuit
D	It is dissipated as heat in the circuit

25. - E6A12

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

Select	Answer
A	To reduce the chance of static damage to the gate
B	To provide a voltage reference for the correct amount of reverse-bias gate voltage
C	To protect the substrate from excessive voltages
D	To keep the gate voltage within specifications and prevent the device from overheating

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	7
B	1
C	6
D	5

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Lower power consumption
B	Immune to damage from static discharge
C	Lower distortion
D	Differential output capability

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids generally require fewer turns to produce a given inductance value
B	Ferrite toroids are easier to use with surface mount technology
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally have better temperature stability

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Excessive lead length
B	Epoxy coating is conductive above 300 MHz
C	Unsuitable for combining analog and digital signals
D	Too many pins

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An amplitude modulated helium-neon laser
B	A frequency modulated helium-neon laser
C	An LED and a phototransistor
D	A lens and a photomultiplier

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	J-K flip-flop
B	Monostable multivibrator
C	Astable multivibrator
D	T flip-flop

32. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A temperature compensating load resistor to improve linearity
C	A low-pass filter to remove switching signal components
D	A matched load resistor to prevent damage by switching transients

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Shape factor
B	Phase response
C	Passband ripple
D	Noise factor

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series current source
B	A series regulator
C	A shunt regulator
D	A shunt current source

35. - E7E05

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

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

36. - E7F03

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

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

37. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-3 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	38
C	76
D	0.03

38. - E7H08

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

Select	Answer
A	NP0 capacitors
B	Wirewound resistors
C	Toroidal inductors
D	Non-inductive resistors

39. - E8A04

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

Select	Answer
A	A small amount of noise added to the input signal to allow more precise representation of a signal over time
B	An error caused by irregular quantization step size
C	An abnormal condition where the converter cannot settle on a value to represent the signal
D	A method of decimation by randomly skipping samples

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	Two or more information streams are merged into a baseband, which then modulates the transmitter
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	The transmitted signal is divided into packets of information
D	The transmitted signal jumps from band to band at a predetermined rate

41. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting extra data that may be used to detect and correct transmission errors
B	By the receiving station repeating each block of three data characters
C	By transmitting a special algorithm to the receiving station along with the data characters
D	By varying the frequency shift of the transmitted signal according to a predefined algorithm

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Bit errors in the modem
B	Ground loops
C	Excessive numbers of retries
D	Excessive transmit audio levels

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?

Select	Answer
A	6.0 dB
B	2.79 dB
C	8.15 dB
D	3.85 dB

44. - E9B01

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

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

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation increases
B	Fewer vertical angle lobes will be present
C	Additional higher vertical angle lobes will appear
D	The low-angle radiation decreases

46. - E9D04

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

Select	Answer
A	To lower the radiation angle
B	To minimize losses
C	To minimize the Q
D	To swamp out harmonics

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Hairpin match
B	Gamma match
C	Double-bazooka match
D	All these choices are correct

48. - E9F09

What is the approximate physical length of a foam polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 7.2 MHz?

Select	Answer
A	8.3 meters
B	6.9 meters
C	10.4 meters
D	5.2 meters

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant resistance
B	Points with constant reactance
C	Frequency
D	SWR

50. - E9H02

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

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

Figure E5-1

Figure E6-2

Figure E7-3

Figure E9-1