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

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1. - E1A02

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?

Select	Answer
A	The exact lower band edge
B	1 kHz above the lower band edge
C	3 kHz above the lower band edge
D	300 Hz above the lower band edge

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station except a Technician class

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	18.110 MHz - 18.168 MHz
B	29.500 MHz - 29.700 MHz
C	10.100 MHz - 10.150 MHz
D	24.940 MHz - 24.990 MHz

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	Any amateur station on the surface of the Earth
B	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space
C	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
D	An amateur station that is not able to communicate using amateur satellites

5. - E1E03

What is a Volunteer Examiner Coordinator?

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

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
B	A line roughly parallel to and south of the U.S.-Canadian border
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and west of the U.S. Atlantic coastline

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From south to north
B	From west to east
C	From north to south
D	From east to west

8. - E2B03

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

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

9. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign and grid square
C	Send your full call sign once or twice
D	Send the call sign of the DX station three times, the words "this is", then your call sign three times

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	APRS
B	FSK441
C	Hellschreiber
D	WSPR

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	Hellschreiber
B	AMTOR
C	RTTY
D	PACTOR

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	The waves are reflected by the ionosphere and return to their source
B	Electric and magnetic fields become aligned as they travel
C	Changing electric and magnetic fields propagate the energy
D	The energy propagates through a medium with a high refractive index

13. - E3B09

At what time of year is Sporadic E propagation most likely to occur?

Select	Answer
A	Around the equinoxes, especially the fall equinox
B	Around the solstices, especially the summer solstice
C	Around the solstices, especially the winter solstice
D	Around the equinoxes, especially the spring equinox

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 15 percent of the distance
B	By approximately four times the distance
C	By approximately twice the distance
D	By approximately 50 percent of the distance

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can run on battery power for remote measurements
B	It does not require an expensive high-precision time base
C	It can directly measure the modulation index of an FM transmitter
D	It provides improved resolution of low-frequency signals within a comparable time period

16. - E4B17

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

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

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	Analog-to-digital converter sample width in bits
B	CPU register width in bits
C	RAM speed used for data storage
D	Anti-aliasing input filter bandwidth

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To provide a range of AGC time constants
B	To store often-used frequencies
C	To increase rejection of unwanted signals
D	To allow selection of the optimum RF amplifier device

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

Select	Answer
A	A clicking noise at intervals of a few seconds
B	The appearance of unstable modulated or unmodulated signals at specific frequencies
C	A loud AC hum in the audio output of your station receiver
D	A whining type noise that continually pulses off and on

20. - E5A11

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

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

21. - E5B03

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

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

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Maidenhead grid
B	Faraday grid
C	Polar coordinates
D	Elliptical coordinates

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	70.7 Watts
B	200 Watts
C	100 Watts
D	141.4 Watts

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Gate 1, gate 2, drain
B	Gate, drain, source
C	Emitter, base 1, base 2
D	Emitter, base, collector

25. - E6B10

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

Select	Answer
A	5
B	6
C	1
D	7

26. - E6C12

What is BiCMOS logic?

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

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	35 turns
B	79 turns
C	13 turns
D	141 turns

28. - E6E10

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

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

29. - E6F12

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

Select	Answer
A	Photons
B	Holes
C	Protons
D	Electrons

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Emitter load
B	Collector load
C	Fixed bias
D	Voltage regulation

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A power supply filter made with interlaced quartz crystals
B	An audio filter made with four quartz crystals that resonate at 1kHz intervals
C	A filter with wide bandwidth and shallow skirts made using quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The controlled device's duty cycle is changed to produce a constant average output voltage
B	The resistance of a control element is varied in direct proportion to the line voltage or load current
C	It is generally less efficient than a linear regulator
D	It gives a ramp voltage at its output

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The frequency components present in the modulating signal
B	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
C	The lowest frequency band that the transmitter or receiver covers
D	The unmodulated bandwidth of the transmitted signal

35. - E7F01

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

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

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	0.21
C	24
D	47

37. - E7H08

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

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

38. - E8A04

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

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

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow band, slow speed transmissions
B	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
C	A bandwidth compression technique using Fourier transforms
D	A frequency modulation technique which uses non-harmonically related frequencies

40. - E8C06

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

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

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It contains fewer information bits per character than any other code
B	It includes built in error correction features
C	It is possible to transmit both upper and lower case text
D	It uses one character as a shift code to send numeric and special characters

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Install a good radial system
B	Shorten the radiating element
C	Isolate the coax shield from ground
D	Reduce the diameter of the radiating element

43. - E9B08

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

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

44. - E9C04

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

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

45. - E9D02

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

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

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be capacitive
B	The driven element resonance must be lower than the operating frequency
C	The driven element reactance must be inductive
D	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line

47. - E9F16

Which of the following is a significant difference between foam dielectric coaxial cable and solid dielectric cable, assuming all other parameters are the same?

Select	Answer
A	Foam dielectric has higher velocity factor
B	Foam dielectric has lower loss per unit of length
C	Foam dielectric has lower safe operating voltage limits
D	All of these choices are correct

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Reactance axis
B	Prime axis
C	Impedance axis
D	Polar axis

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	A very sharp single null
B	High-radiation angle
C	Broad band response
D	A very sharp peak

50. - E0A11

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

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

Figure E6-3

Figure E7-2

Figure E7-4

Figure E9-3