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?

Select	Answer
A	Ingestion of ozone gas from the cooling system
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Blood clotting from the intense magnetic field
D	Hearing loss caused by high voltage corona discharge

2. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	At the highest frequency of the channel
B	At the center frequency of the channel
C	On any frequency where the signal's sidebands are within the channel
D	At the lowest frequency of the channel

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 obtain a construction permit from the airport zoning authority
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 submit engineering drawings to the FAA

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	ITU reciprocal license
B	All these choices are correct
C	IARP agreement
D	CEPT agreement

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of Amateur Extra Class operators
B	Only those of General, Advanced or Amateur Extra Class operators
C	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
D	Any amateur station, subject to the privileges of the class of operator license held by the control operator

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The VEs
B	The FCC
C	The VECs
D	The ARRL

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must be capable of external RF switching between its input and output networks
C	It must exhibit a gain of 0 dB or less over its full output range
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

8. - E2A12

What is the purpose of digital store-and-forward functions on an amateur radio satellite?

Select	Answer
A	To relay messages between satellites
B	To store digital messages in the satellite for later download by other stations
C	To delay download of telemetry between satellites
D	To upload operational software for the transponder

9. - E2B05

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

Select	Answer
A	The vestigial sideband carries the audio information
B	Vestigial sideband provides high frequency emphasis to sharpen the picture
C	The vestigial sideband contains chroma information
D	Vestigial sideband reduces bandwidth while allowing for simple video detector circuitry

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	Forward error correction and Viterbi codes
D	Discovery and link establishment protocols

11. - E2D01

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

Select	Answer
A	WSPR
B	MSK144
C	APRS
D	Hellschreiber

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	Your transmit frequency is incorrect
D	The protocol version you are using is not supported by the digital station

13. - E3A09

Which of the following frequency ranges is most suited for meteor scatter communications?

Select	Answer
A	220 MHz - 450 MHz
B	1.8 MHz - 1.9 MHz
C	10 MHz - 14 MHz
D	28 MHz - 148 MHz

14. - E3B11

At what time of day can sporadic E propagation occur?

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class B
C	Class A
D	Class M

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the analyzer via a high-impedance transformer to the antenna
B	Loosely couple the analyzer near the antenna base
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the antenna feed line directly to the analyzer's connector

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test
B	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
C	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
D	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of thermal noise to atmospheric noise
B	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network
C	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
D	The ratio of atmospheric noise to phase noise

19. - E4D07

Which of the following reduces the likelihood of receiver desensitization?

Select	Answer
A	Switch from fast AGC to slow AGC
B	Decrease the RF bandwidth of the receiver
C	Raise the receiver IF frequency
D	Increase the receiver front end gain

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Ringing in the DSP filter will completely remove the spaces between the CW characters
B	Any nearby signal passing through the DSP system will overwhelm the desired signal
C	Removal of the CW signal as well as the interfering carrier
D	Received CW signals will appear to be modulated at the DSP clock frequency

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Higher self-resonant frequency
B	Lower losses
C	Lower reactance
D	Lower self-resonant frequency

22. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	68.2 degrees with the voltage leading the current
B	14.0 degrees with the voltage lagging the current
C	68.2 degrees with the voltage lagging the current
D	14.0 degrees with the voltage leading 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 3
B	Point 8
C	Point 7
D	Point 1

24. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Lightweight transmission line made of common zip cord
C	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits
D	Miniature coax used for low power applications

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In high-power audio circuits
B	In microwave circuits
C	In high-current rectifier circuits
D	In very low-frequency RF circuits

26. - E6B07

What is the failure mechanism when a junction diode fails due to excessive current?

Select	Answer
A	Excessive junction temperature
B	Charge carrier depletion
C	Excessive inverse voltage
D	Insufficient forward voltage

27. - E6C03

What is tri-state logic?

Select	Answer
A	Low-power logic devices designed to operate at 3 volts
B	Logic devices with 0, 1, and high-impedance output states
C	Proprietary logic devices manufactured by Tri-State Devices
D	Logic devices that utilize ternary math

28. - E6D08

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

Select	Answer
A	Powdered-iron cores generally require fewer turns to produce a given inductance
B	Powdered-iron cores generally maintain their characteristics at higher currents
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores use smaller diameter wire for the same inductance

29. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Surface mount
B	Radial lead
C	TO-220
D	Axial lead

30. - E6F01

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

Select	Answer
A	Holes
B	Photons
C	Protons
D	Electrons

31. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic 1 at its output if all inputs are logic 0
B	It only produces logic 0 at its output when all inputs are logic 1
C	It produces logic 0 at its output if all inputs are logic 1
D	It produces logic 1 at its output if any or all inputs are logic 1

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common emitter
B	Common collector
C	Common base
D	Emitter follower

33. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a high-pass filter
C	It is a notch filter
D	It is a low-pass filter

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

35. - E7E10

How does a diode envelope detector function?

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

36. - E7F02

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

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

37. - E7G01

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

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

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Digital conversion noise
C	Spurious signals at discrete frequencies
D	Broadband noise

39. - E8A04

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

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

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	0.214
B	47
C	0.47
D	2.14

41. - E8C06

What is the bandwidth of a 170-hertz shift, 300-baud ASCII transmission?

Select	Answer
A	1.0 kHz
B	0.5 kHz
C	0.3 kHz
D	0.1 Hz

42. - E8D04

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

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

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Power factor
B	Half-power bandwidth
C	Effective radiated power
D	Apparent power

44. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from a theoretical isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	They are the same
B	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
C	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
D	The total amount of radiation from the directional antenna is increased by the gain of the antenna

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?

Select	Answer
A	A figure-8 oriented along the axis of the array
B	Cardioid
C	Omni-directional
D	A figure-8 broadside to the axis of the array

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	SWR bandwidth decreases
C	Gain is reduced
D	SWR bandwidth increases

47. - E9E07

What parameter describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Reflection coefficient
B	Characteristic impedance
C	Dielectric constant
D	Velocity factor

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower velocity factor
B	Lower loss
C	Higher SWR
D	Smaller reflection coefficient

49. - E9G10

What do the arcs on a Smith chart represent?

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

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

Figure E5-1

Figure E7-1