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. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any FCC-issued amateur license
B	Only General class or higher amateur licenses
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	An unrestricted Radiotelephone Operator Permit

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 53 dB below
B	At least 43 dB below
C	At least 63 dB below
D	At least 73 dB below

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 auxiliary, beacon or space stations
C	Only beacon, repeater or space stations
D	Only earth stations, repeater stations or model craft

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio communications service using amateur radio stations on satellites
B	A radio communications service using stations on Earth satellites for public service broadcast
C	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
D	A spacecraft launching service for amateur-built satellites

5. - E1E05

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

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

6. - E1F08

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

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

7. - E2A13

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	LEO
B	HEO
C	Geostationary
D	Geomagnetic

8. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the SSTV mode being used
B	To lock the color burst oscillator in color SSTV images
C	To identify the call sign of the station transmitting
D	To provide vertical synchronization

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

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Unnumbered Information
B	Connect
C	Acknowledgement
D	Disconnect

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	Another station you are unable to hear is using the frequency
C	All of these choices are correct
D	The protocol version you are using is not the supported by the digital station

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	FM
B	SSB
C	RTTY
D	CW

13. - E3B09

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

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

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	A meteor ping
B	A solar flare has occurred
C	Long-path propagation is occurring
D	Increased transequatorial propagation likely

15. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	Antenna analyzers do not need an external RF source
C	All of these choices are correct
D	Antenna analyzers display a time-varying representation of the modulation envelope

16. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Relative quality of the data
C	The port or ports at which measurements are made
D	Frequency order of the measurements

17. - E4C16

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

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

18. - E4D09

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

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

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By installing a high pass filter in series with the motor's power leads
C	By installing a bypass capacitor in series with the motor leads
D	By using a ground-fault current interrupter in the circuit used to power the motor

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage and current are in phase
B	The voltage leads the current by 90 degrees
C	The current leads the voltage by 90 degrees
D	The voltage and current are 180 degrees out of phase

21. - E5B10

What is the relationship between the current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage and current are 180 degrees out of phase
B	Voltage leads current by 90 degrees
C	Current leads voltage by 90 degrees
D	Voltage and current are in phase

22. - E5C09

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

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

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	Because of ground reflections
C	To reduce phase shift along the connection
D	To increase neutralizing resistance

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	They are both high impedance
B	An FET has low input impedance; a bipolar transistor has high input impedance
C	An FET has high input impedance; a bipolar transistor has low input impedance
D	They are both low impedance

25. - E6B06

Which of the following is a common use of a hot-carrier diode?

Select	Answer
A	As a VHF/UHF mixer or detector
B	As balanced mixers in FM generation
C	As a constant voltage reference in a power supply
D	As a variable capacitance in an automatic frequency control circuit

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The IC input can be damaged
B	The comparator changes its output state
C	The feedback loop becomes unstable
D	The comparator enters latch-up

27. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Mechanical deformation of material by the application of a voltage
C	Increased conductivity in the presence of light
D	Generation of electrical energy in the presence of light

28. - E6E03

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

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

29. - E6F06

Which of these materials is affected the most by photoconductivity?

Select	Answer
A	A crystalline semiconductor
B	A liquid semiconductor
C	An ordinary metal
D	A heavy metal

30. - E7A03

Which of the following can divide the frequency of a pulse train by 2?

Select	Answer
A	A flip-flop
B	An XOR gate
C	An OR gate
D	A multiplexer

31. - E7B03

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

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

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a notch filter
B	It is a high-pass filter
C	It is a band-pass filter
D	It is a low-pass filter

33. - E7D08

What type of circuit is shown in Figure E7-3?

Select	Answer
A	Linear voltage regulator
B	Emitter follower
C	Switching voltage regulator
D	Grounded emitter amplifier

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An FM generator circuit
B	A circuit for filtering two closely adjacent signals
C	A circuit for detecting FM signals
D	An automatic band-switching circuit

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Missing codes and jitter
B	Sample clock phase noise
C	Reference voltage level and sample width in bits
D	Data storage transfer rate

36. - E7G08

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

Select	Answer
A	It does not vary with frequency
B	It decreases logarithmically with increasing frequency
C	It increases linearly with increasing frequency
D	It decreases linearly with increasing frequency

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a capacitive divider
C	Through link coupling
D	Through a tapped coil

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	2.5 to 1
B	25 to 1
C	1 to 1
D	100 to 1

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	2000
B	3
C	6000
D	1/3

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, redundant data is substituted
B	Special binary codes provide automatic correction
C	If errors are detected, a retransmission is requested
D	Special polynomial codes provide automatic correction

41. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	Low-pass filters at the transmitter output
B	Increase keying waveform rise and fall times
C	High-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

42. - E9A16

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	126 watts
B	300 watts
C	2000 watts
D	317 watts

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Mutual impedance analysis
B	Graphical analysis
C	Method of Moments
D	Calculus differentiation with respect to physical properties

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	Cardioid
B	Omni-directional
C	A Figure-8 end-fire along the axis of the array
D	A Figure-8 broadside to the axis of the array

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Greater structural strength
C	Higher losses
D	Lower Q

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

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

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	A capacitive reactance
D	The same as the characteristic impedance of the line

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	Impedance axis
B	Polar axis
C	Prime axis
D	Reactance axis

49. - E9H09

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

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

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
B	Only commercial transmitters
C	Only the most powerful transmitter
D	Each transmitter operating with a duty-cycle greater than 50 percent

Figure E7-3

Figure E9-3