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	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	Its operation must be approved by the master of the ship or the pilot in command of the aircraft

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	A form FSD-15 must be submitted to the Department of the Interior
B	A proposal must be submitted to the National Park Service
C	An Environmental Assessment must be submitted to the FCC
D	A letter of intent must be filed with the National Audubon Society

3. - E1C04

What is meant by IARP?

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

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
B	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
C	An amateur station located more than 50 km above the Earth's surface
D	An amateur station that transmits telemetry consisting of measurements of upper atmosphere

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 74%
B	Minimum passing score of 80%
C	Minimum passing score of 77%
D	Minimum passing score of 70%

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	420 MHz - 430 MHz
C	440 MHz - 450 MHz
D	53 MHz - 54 MHz

7. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The uplink and downlink frequency ranges
B	The polarization of uplink and downlink signals
C	Power limits for uplink and downlink transmissions
D	The location of the ground control station

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	600 Hz
B	2 MHz
C	3 kHz
D	6 MHz

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a lower frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Wait 90 minutes or so for the signal degradation to pass
D	Switch to a higher frequency HF band

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Judging optimum transmission times by monitoring beacons reflected from the Moon
B	High speed CW identification to avoid fading
C	Time synchronous transmissions alternately from each station
D	Storing and forwarding digital messages

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO
B	Audio FSK can be performed anywhere in the transmit chain
C	Audio FSK has a superior frequency response
D	Direct FSK uses a DC-coupled data connection

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves with a rotating electric field
C	Waves produced by a loop antenna
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. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Moderate solar wind
B	An extreme geomagnetic storm
C	Waning sunspot numbers
D	Very low solar activity

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A spectrum analyzer
B	A time-domain reflectometer
C	A wattmeter
D	A logic analyzer

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
B	Short circuit, open circuit, and resonant circuit
C	Short circuit, open circuit, and 50 ohms
D	50 ohms, 75 ohms, and 90 ohms

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Distortion
B	Overload
C	Excess output level
D	Loss of sensitivity

18. - 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	146.34 MHz and 146.61 MHz
B	173.35 MHz and 139.40 MHz
C	146.10 MHz and 147.30 MHz
D	146.88 MHz and 146.34 MHz

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	Ignition noise
B	Heterodyne interference
C	All of these choices are correct
D	Broadband white noise

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

Select	Answer
A	Approximately equal to inductive reactance
B	High, as compared to the circuit resistance
C	Approximately equal to capacitive reactance
D	Approximately equal to circuit resistance

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	It is unchanged
C	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance
D	The sign is reversed

22. - E5C11

What do the two numbers that are used to define a point on a graph using rectangular coordinates represent?

Select	Answer
A	The coordinate values along the horizontal and vertical axes
B	The sine and cosine values
C	The magnitude and phase of the point
D	The tangent and cotangent values

23. - E5D03

What is microstrip?

Select	Answer
A	Lightweight transmission line made of common zip cord
B	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
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

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Acceptor impurity
B	Donor impurity
C	Insulator impurity
D	N-type impurity

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	6
B	5
C	1
D	7

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	An integrated circuit logic family using both bipolar and CMOS transistors
B	A logic device with two CMOS circuits per package
C	A FET logic family based on bimetallic semiconductors
D	A logic family based on bismuth CMOS devices

27. - E6D13

What is the primary cause of inductor self-resonance?

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

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Wave-soldering construction
B	Point-to-point construction
C	Microstrip construction
D	Ground-plane construction

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
B	A frequency-determining unit for a transmitter or receiver
C	A display that uses a glowing liquid to remain brightly lit in dim light
D	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "OR" gate
B	A clock
C	An "AND" gate
D	A flip-flop

31. - E7B10

In Figure E7-1, what is the purpose of R1 and R2?

Select	Answer
A	Self bias
B	Fixed bias
C	Feedback
D	Load resistors

32. - E7C14

Which mode is most affected by non-linear phase response in a receiver IF filter?

Select	Answer
A	Digital
B	Single-Sideband voice
C	Video
D	Meteor scatter

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To allow for remote control of the power supply
B	To provide a dual-voltage output for reduced power applications
C	To compensate for variations of the incoming line voltage
D	To allow the filter capacitors to charge gradually

34. - E7E04

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

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

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	More taps
B	Higher data rate
C	Complex phasor representations
D	Double-precision math routines

36. - E7G01

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

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

37. - E7H12

Which of the following must be done to insure 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 inductance
C	Bias the crystal at a specified current
D	Provide the crystal with a specified parallel capacitance

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	256 divided by the gain of the input amplifier
C	256
D	8

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	3
B	3000
C	1000
D	0.3

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is only used for RTTY
C	Baud is twice the symbol rate
D	Symbol rate is only used for packet-based modes

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus transmission resistance
C	Radiation resistance plus space impedance
D	Radiation resistance plus ohmic resistance

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The lobes align more in the direction of the wire
C	The lobes become more perpendicular to the wire
D	The front-to-back ratio decreases

45. - E9D08

What happens as the Q of an antenna increases?

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

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 gamma matching system
B	The stub matching system
C	The omega matching system
D	The delta matching system

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	An inductive reactance
B	The same as the input impedance of the final generator stage
C	The same as the characteristic impedance of the line
D	A capacitive reactance

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By increasing the number of wire turns in the loop and reducing the area of the loop structure
B	By reducing the permeability of the loop shield
C	By winding adjacent turns in opposing directions
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

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

Figure E6-3

Figure E7-1