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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	17 meter band
B	12 meter band
C	60 meter band
D	30 meter band

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	0.5
B	1.0
C	2.0
D	3.0

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Repeater and auxiliary stations may not be remotely controlled
B	A control operator need not be present at the control point
C	Only Extra Class operators may be the control operator of a remote station
D	A control operator must be present at the control point

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	All except Technician Class
B	Only Amateur Extra Class
C	Only General, Advanced or Amateur Extra Class
D	Any class with appropriate operator privileges

5. - E1E03

What is a Volunteer Examiner Coordinator?

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

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
B	It must exhibit a gain of 0 dB or less over its full output range
C	It must be capable of external RF switching between its input and output networks
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

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

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	90
B	120
C	60
D	30

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Store and forward on the 440 MHz band
B	Multiple Frequency Shift Keying in the 10 GHz band
C	Frequency division multiplex in the 24 GHz band
D	Spread spectrum in the 2.4 GHz band

10. - E2D01

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

Select	Answer
A	WSPR
B	APRS
C	FSK441
D	Hellschreiber

11. - E2E05

Which type of digital mode does not support keyboard-to-keyboard operation?

Select	Answer
A	Winlink
B	MFSK
C	RTTY
D	PSK31

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
B	The interaction in the F2 layer between the solar wind and the Van Allen belt
C	Meteor showers concentrated in the extreme northern and southern latitudes
D	A low sunspot level combined with tropospheric ducting

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. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	An increase in the critical frequency
B	Decreasing disruption of the geomagnetic field
C	Increasing disruption of the geomagnetic field
D	Higher levels of solar UV radiation

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	False signals are displayed
B	All signals will have a DC offset
C	False triggering occurs
D	Calibration of the vertical scale is no longer valid

16. - E4B16

Which S parameter represents return loss or SWR?

Select	Answer
A	S12
B	S11
C	S22
D	S21

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Capture effect
B	Desensitization
C	Cross-modulation interference
D	Frequency discrimination

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
B	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By using a ground-fault current interrupter in the circuit used to power the motor
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 installing a brute-force AC-line filter in series with the motor leads

20. - E5A05

What is the magnitude of the current at the input of a series RLC circuit as the frequency goes through resonance?

Select	Answer
A	Maximum
B	Minimum
C	L/R
D	R/L

21. - E5B03

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

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

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	Reactive component
D	The sum of the reactive and resistive components

23. - E5D05

Which parasitic characteristic increases with conductor length?

Select	Answer
A	Inductance
B	Malleability
C	Permeability
D	Permittivity

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	Alpha cutoff frequency
B	Alpha rejection frequency
C	Corner frequency
D	Beta cutoff frequency

25. - E6B06

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

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

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	3
B	1
C	4
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 maintain their characteristics at higher currents
C	Powdered-iron cores generally have greater initial permeability
D	Powdered-iron cores generally require fewer turns to produce a given inductance

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	Surface mount
D	Virtual lead mounting

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device which detects rotation of a control by interrupting a light source with a patterned wheel
B	A digital encryption device often used to encrypt spacecraft control signals
C	A device which measures the strength of a beam of light using analog to digital conversion
D	A device for generating RTTY signals by means of a rotating light source

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	High power gain
B	High filament voltage
C	Low input impedance
D	Low bandwidth

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter
B	An automatic notch filter
C	A special filter that emphasizes image responses
D	A variable bandwidth crystal lattice filter

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	Pass transistor
C	Reference voltage
D	Switching inductance

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable resistance
D	To produce PM signals by using an electrically variable resistance

35. - E7F11

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

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

36. - E7G06

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

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

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a tapped coil
C	Through link coupling
D	Through a quartz crystal

38. - E8A06

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

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

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are arranged to share discrete time slots of a data transmission
B	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
C	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
D	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code

42. - E9A04

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

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

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	7
B	4
C	1
D	3

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

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To increase the SWR bandwidth
C	To lower the losses
D	To cancel capacitive reactance

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Characteristic impedance
B	Dielectric constant
C	Reflection coefficient
D	Velocity factor

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

Select	Answer
A	The center conductor resistivity
B	The termination impedance
C	The line length
D	Dielectric materials used in the line

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It modifies the pattern of a DF antenna array to provide a null in one direction
C	It provides diversity reception that cancels multipath signals
D	It allows DF antennas to receive signals at different vertical angles

50. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	Signal Amplification Rating
C	The rate of RF energy reflected from stationary terrain
D	The rate at which RF energy is absorbed by the body

Figure E6-5

Figure E9-2