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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A01

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

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

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served
B	Only those club stations licensed to Amateur Extra class operators
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. - E1C10

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

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

4. - E1D03

What is a telecommand station in the amateur satellite service?

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

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Warn the candidate that continued failure to comply will result in termination of the examination
B	Allow the candidate to complete the examination, but invalidate the results
C	Immediately terminate everyone's examination and close the session
D	Immediately terminate the candidate's examination

6. - E1F01

On what frequencies are spread spectrum transmissions permitted?

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

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	An isotropic antenna
B	A log-periodic dipole array
C	A circularly polarized antenna
D	A linearly polarized antenna

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone amplitude
B	Sync amplitude
C	Tone frequency
D	Sync frequency

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A 440 MHz transceiver with a 9600 baud modem
C	An optical cable connection between the USB ports of 2 separate computers
D	A standard wireless router running custom software

10. - E2D01

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

Select	Answer
A	WSPR
B	FSK441
C	APRS
D	Hellschreiber

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	RTTY
B	PACTOR
C	PSK31
D	MT63

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Sprites and jets
B	Gray-line
C	Warm and cold fronts
D	Lightning discharges

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Receipt of a signal by more than one path
B	High D layer absorption
C	Transmit frequency is higher than the MUF
D	Meteor scatter

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Evaluating high voltage sources for X-Rays
B	The process in which an electronic display presents a pattern
C	Modeling a radio wave's path through the ionosphere
D	Determining the radiation pattern from an array of antennas

15. - E4A05

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

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

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S22
B	S11
C	S21
D	S12

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

Select	Answer
A	The galactic noise contribution to minimum detectable signal
B	The theoretical noise at the input of a perfect receiver at room temperature
C	The minimum detectable signal as a function of receive frequency
D	The noise figure of a 1 Hz bandwidth receiver

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

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

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

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

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	7.12 MHz
B	7.12 kHz
C	23.5 MHz
D	23.5 kHz

21. - E5B05

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

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

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	Reactive component
B	The sum of the reactive and resistive components
C	Resistive component
D	The difference between the resistive and reactive components

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	1.414
C	0.5
D	1.73

24. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Beta cutoff frequency
B	Corner frequency
C	Alpha rejection frequency
D	Alpha cutoff frequency

25. - E6B04

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

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

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	4
B	1
C	3
D	2

27. - E6D08

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

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

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Silicon dioxide
D	Gallium nitride

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It becomes unstable
B	It increases
C	It stays the same
D	It decreases

30. - E7A12

What type of logic defines "0" as a high voltage?

Select	Answer
A	Negative logic
B	Reverse Logic
C	Positive Logic
D	Assertive Logic

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A low-pass filter to remove switching signal components
B	A matched load resistor to prevent damage by switching transients
C	A temperature compensating load resistor to improve linearity
D	A high-pass filter to compensate for low gain at low frequencies

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 transformation range
D	Greater harmonic suppression

33. - E7D11

What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Select	Answer
A	Error amplifier
B	Reference voltage
C	Switching inductance
D	Pass transistor

34. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A de-emphasis network
B	A pre-emphasis network
C	An audio prescaler
D	A heterodyne suppressor

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Combine signals with a quadrature phase relationship
B	A frequency synthesizer removes the unwanted sidebands
C	Mixing products are converted to voltages and subtracted by adder circuits
D	Emulation of quartz crystal filter characteristics

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	For smoothing power supply output
B	As an audio filter in a receiver
C	As a high-pass filter used to block RFI at the input to receivers
D	As a low-pass filter used between a transmitter and a transmission line

37. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A phase locked loop synthesizer
B	A diode-switching matrix synthesizer
C	A hybrid synthesizer
D	A direct digital synthesizer

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A sawtooth wave
B	A square wave
C	A sine wave
D	A cosine wave

39. - E8B10

What describes frequency division multiplexing?

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

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

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

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Harmonics on higher bands
B	Rapid signal fading
C	High reflected power
D	Strong ALC action

42. - E9A04

Which of the following factors may affect the feed point impedance of an antenna?

Select	Answer
A	Sunspot activity and time of day
B	Transmission-line length
C	The settings of an antenna tuner at the transmitter
D	Antenna height, conductor length/diameter ratio and location of nearby conductive objects

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	75 degrees
B	45 degrees
C	7.5 degrees
D	25 degrees

44. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus rocky ground?

Select	Answer
A	The low-angle radiation decreases
B	The low-angle radiation increases
C	The high-angle radiation increases
D	Both the high-angle and low-angle radiation decrease

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To maximize losses
C	To minimize losses
D	To swamp out harmonics

46. - 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 epsilon match
B	The delta match
C	The gamma match
D	The stub match

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

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Impedance along transmission lines
C	Radio propagation
D	Antenna radiation pattern

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	A vertical antenna coupled to a feed line through an inductive loop of wire
B	A large circularly polarized antenna
C	One or more turns of wire wound in the shape of a large open coil
D	A small coil of wire tightly wound around a toroidal ferrite core

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Advise your neighbors of the results of your tests
B	You need only evaluate exposure levels on your own property
C	Make sure signals from your station are less than the controlled MPE limits
D	Make sure signals from your station are less than the uncontrolled MPE limits

Figure E6-5

Figure E9-2