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	Mica
B	Uranium Hexafluoride
C	Zinc oxide
D	Beryllium Oxide

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	18.107 MHz
B	18.068 MHz
C	18.110 MHz
D	18.100 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	State and local zoning
B	FAA tower height limits
C	Use of wireless devices in vehicles
D	Homeowners associations

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators must not operate until approval is received
C	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D11

Which amateur stations are eligible to operate as Earth stations?

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

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
B	A person who has volunteered to prepare amateur operator license examinations
C	The person who has entered into an agreement with the FCC to be the VE session manager
D	A person who has volunteered to administer amateur operator license examinations

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 222 MHz
B	Only on amateur frequencies above 144 MHz
C	Only on amateur frequencies above 420 MHz
D	Only on amateur frequencies above 50 MHz

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To avoid reducing the downlink power to all other users
C	To avoid interfering with terrestrial QSOs
D	To prevent the satellite from emitting out-of-band signals

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

10. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	30 meters
B	2 meters
C	33 centimeters
D	6 meters

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
B	All these choices are correct
C	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
D	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	FSK
C	Pulse modulation
D	Spread spectrum

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	An extreme low-pressure area in the polar regions
B	Meteor showers concentrated in the extreme northern and southern latitudes
C	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

14. - E3B04

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

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

15. - E3C13

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

Select	Answer
A	Horizontal
B	Circular
C	Elliptical
D	Vertical

16. - E4A08

Which of the following measures SWR?

Select	Answer
A	An ohmmeter
B	An antenna analyzer
C	A spectrum analyzer
D	A Q meter

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	There is an impedance mismatch between the antenna and feed line
B	The transmitter is not properly neutralized
C	There is more power going into the antenna
D	There is possibly a short to ground in the feed line

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-148 dBm
B	-155 dBm
C	-174 dBm
D	-164 dBm

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.88 MHz and 146.34 MHz
B	146.10 MHz and 147.30 MHz
C	173.35 MHz and 139.40 MHz
D	146.34 MHz and 146.61 MHz

20. - E4E10

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	All these choices are correct
B	Arcing contacts in a thermostatically controlled device
C	A malfunctioning illuminated advertising display
D	A defective doorbell or doorbell transformer inside a nearby residence

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	436.6 kHz
B	15.7 kHz
C	31.4 kHz
D	218.3 kHz

22. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

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

23. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative magnitude
B	A positive magnitude
C	A positive phase angle
D	A negative phase angle

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in circuit Q
B	Power lost because of capacitor leakage
C	Wattless, nonproductive power
D	Power consumed in wire resistance in an inductor

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	Any FET for which holes are the majority carriers
D	An FET that has no current flow between source and drain when no gate voltage is applied

26. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As a high-voltage rectifier
B	As an RF detector
C	As a constant voltage source
D	As a constant current source

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	4
B	5
C	6
D	2

28. - E6D07

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

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

29. - E6E09

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

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

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators eliminate the effects of reflected light in the control circuit
B	Optoisolators provide a low impedance link between a control circuit and a power circuit
C	Optoisolators provide impedance matching between the control circuit and power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 0 at its output only when all inputs are logic 1
B	It produces logic 0 at its output if some but not all inputs are logic 1
C	It produces logic 0 at its output only when all inputs are logic 0
D	It produces logic 1 at its output only when all inputs are logic 1

32. - E7B15

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

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

33. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	It cancels the reactive part of the impedance and changes the resistive part to a desired value
B	Reactive currents are dissipated in matched resistances
C	It introduces transconductance to cancel the reactive part of impedance
D	It introduces negative resistance to cancel the resistive part of impedance

34. - E7D01

How does a linear electronic voltage regulator work?

Select	Answer
A	It has a ramp voltage as its output
B	The conduction of a control element is varied to maintain a constant output voltage
C	It eliminates the need for a pass transistor
D	The control element duty cycle is proportional to the line or load conditions

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a loop modulator followed by a mixer
B	By using a reactance modulator followed by a mixer
C	By driving a product detector with a DSB signal
D	By using a balanced modulator followed by a filter

36. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	A switching mixer is used to generate I and Q signals directly from the RF input
B	Software is converted from source code to object code during operation of the receiver
C	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
D	Incoming RF is converted to a control voltage for a voltage controlled oscillator

37. - E7G08

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

Select	Answer
A	It increases linearly with increasing frequency
B	It decreases logarithmically with increasing frequency
C	It does not vary with frequency
D	It decreases 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	Bias the crystal at a specified voltage
B	Provide the crystal with a specified parallel capacitance
C	Bias the crystal at a specified current
D	Provide the crystal with a specified parallel inductance

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The degree of carrier suppression
B	Speech characteristics
C	Amplifier gain
D	The frequency of the modulating signal

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

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	104 Hz
B	52 Hz
C	13 Hz
D	26 Hz

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Foreign language characters can be sent
B	Some types of errors can be detected
C	Faster transmission rate
D	The signal can overpower interfering signals

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

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 total amount of radiation from the directional antenna is increased by the gain of the antenna
C	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
D	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A portable antenna erected using two push support poles
B	An end-fed folded dipole antenna
C	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
D	A wideband vertical antenna constructed from precisely tapered aluminum tubing

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at the feed point
C	It is decreased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The stub match
B	The epsilon match
C	The delta match
D	The gamma match

48. - E9F07

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

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

49. - E9G10

What do the arcs on a Smith chart represent?

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

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It adds capacitive loading, increasing the bandwidth of the antenna
B	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
C	It increases signal strength by providing a better match to the feed line
D	It eliminates tracking errors caused by strong out-of-band signals

Figure E6-3