US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	10 miles
D	3 miles

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, repeater or space stations
B	Only beacon, repeater or space stations
C	Only earth stations, repeater stations or model craft
D	Only auxiliary, beacon or space stations

4. - 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	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
C	Only those of Amateur Extra Class operators
D	Only those of General, Advanced or Amateur Extra Class operators

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
B	The prospective VE obtains accreditation from the FCC
C	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
D	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
B	Communications that have a political content, except as allowed by the Fairness Doctrine
C	Communications that have a religious content
D	Communications in a language other than English

7. - E2A08

Why should effective radiated power to a satellite which 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

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Spectral Intensity
C	Hue
D	Luminance

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts between a U.S. station and a non-U.S. station
B	Special event contacts between stations in the U.S.
C	Contacts using tactical call signs
D	Repeater contacts between U.S. club members

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	300 baud packet
B	170 Hz shift, 45 baud RTTY
C	AMTOR
D	PSK31

11. - E2E03

How is the timing of JT65 contacts organized?

Select	Answer
A	Alternating transmissions at 1 minute intervals
B	By exchanging ACK/NAK packets
C	Stations take turns on alternate days
D	It depends on the lunar phase

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with a rotating electric field
B	Waves produced by a loop antenna
C	Waves with an electric field bent into a circular shape
D	Waves that circle the Earth

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
D	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

14. - E3C09

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

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

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	All of these choices are correct
B	Storage of traces for future reference
C	Manipulation of time base after trace capture
D	Automatic amplitude and frequency numerical readout

16. - E4B10

Which of the following describes a method to measure intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter with two non-harmonically related audio frequencies and observe the RF output with a spectrum analyzer
B	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a peak reading wattmeter
C	Modulate the transmitter with two harmonically related audio frequencies and observe the RF output with a logic analyzer
D	Modulate the transmitter with two non-harmonically related radio frequencies and observe the RF output with a spectrum analyzer

17. - 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	-155 dBm
B	-148 dBm
C	-174 dBm
D	-164 dBm

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Cross-modulation interference
B	Desensitization
C	Squelch gain rollback
D	Quieting

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Geomagnetic storms
C	Meteor showers
D	Solar radio frequency emissions

20. - E5A02

What is resonance in an electrical circuit?

Select	Answer
A	The frequency at which the reactive impedance equals the resistive impedance
B	The frequency at which the capacitive reactance equals the inductive reactance
C	The highest frequency that will pass current
D	The lowest frequency that will pass current

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	B
B	G
C	X
D	Y

22. - E5C16

Which point on Figure E5-2 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 1
B	Point 7
C	Point 8
D	Point 3

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.0
C	0.707
D	0.5

24. - E6A13

What do the initials CMOS stand for?

Select	Answer
A	Common Mode Oscillating System
B	Common Mode Organic Silicon
C	Complementary Metal-Oxide Semiconductor
D	Complementary Mica-Oxide Silicon

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Varactor diode
C	Tunnel diode
D	Silicon-controlled rectifier

26. - 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

27. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	79 turns
B	141 turns
C	13 turns
D	35 turns

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Direct soldering
C	Virtual lead mounting
D	Surface mount

29. - E6F03

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

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

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "1" at its output if any single input is logic "1"
B	It produces logic "1" at its output only if all inputs are logic "1"
C	It produces logic "0" at its output if any single input is logic "1"
D	It produces logic "0" at its output only if all inputs are logic "0"

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Push-pull
B	Class AB
C	Push-push
D	Class C

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Higher efficiency
B	Lower losses
C	Greater harmonic suppression
D	Greater transformation range

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	It bypasses hum around D1
B	It is a brute force filter for the output
C	To provide fixed DC bias for Q1
D	To self-resonate at the hum frequency

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce PM signals
B	By varying the tuning of a microphone preamplifier to produce AM signals
C	By varying the tuning of an amplifier tank circuit to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce PM signals

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At the same rate as the highest frequency component of the signal
B	At four times the rate of the highest frequency component of the signal
C	At half the rate of the highest frequency component of the signal
D	At twice the rate of the highest frequency component of the signal

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Restrict both gain and Q
B	Increase both gain and Q
C	Restrict gain but increase Q
D	Restrict Q but increase gain

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Wide-band AF and RF power amplification
C	Comparison of two digital input signals, digital pulse counter
D	Frequency synthesis, FM demodulation

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	8 multiplied by the gain of the input amplifier
B	8
C	256 divided by the gain of the input amplifier
D	256

39. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	Extremely low-power contacts
B	EME
C	High speed digital modes
D	OFDM signals are not allowed on amateur bands

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It has more possible states than simple binary
B	It facilitates error detection
C	It increases security
D	It has more resolution than simple binary

41. - 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	Frequency hopping
C	Binary phase-shift keying
D	Phase compandored spread spectrum

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
B	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
C	The final amplifier gain minus the transmission line losses
D	The ratio of the signal in the forward direction to that in the opposite direction

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	SWR vs frequency charts
B	All of these choices are correct
C	Antenna gain
D	Polar plots of the far field elevation and azimuth patterns

44. - E9C06

What is the effect of a terminating resistor on a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from horizontal to vertical polarization
B	It changes the radiation pattern from bidirectional to unidirectional
C	It decreases the ground loss
D	It reflects the standing waves on the antenna elements back to the transmitter

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
B	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes

46. - 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 gamma matching system
D	The stub matching system

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
B	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum
C	The ratio of the characteristic impedance of the line to the terminating impedance
D	The index of shielding for coaxial cable

48. - E9G07

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be configured as a four-sided loop
B	It must be mounted more than 1 wavelength above ground
C	It should be one or more wavelengths long
D	Its overall length must not exceed 1/4 wavelength

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polymorphic silicon
B	Polychlorinated Biphenyls
C	Polytetrafluroethylene
D	Polyethylene

Figure E5-2

Figure E7-3

Figure E9-3