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

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

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area in Florida surrounding Cape Canaveral
C	An area in Puerto Rico surrounding the Arecibo Radio Telescope
D	An area surrounding the National Radio Astronomy Observatory

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	The use of a control link between a control point and a locally controlled station
B	The use of devices and procedures for control so that the control operator does not have to be present at a control point
C	A station operating with its output power controlled automatically
D	Remotely controlling a station's antenna pattern through a directional control link

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm only
B	70 cm and 13 cm
C	33 cm and 13 cm
D	70 cm and 33 cm

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare 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 administer amateur operator license examinations
D	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide additional spectrum for personal use
B	To provide for experimental amateur communications
C	To allow regular operation on Land Mobile channels
D	To provide temporary operation while awaiting normal licensing

7. - E2A13

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

Select	Answer
A	LEO
B	Geostationary
C	HEO
D	Geomagnetic

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	128 or 256
B	30 or 60
C	180 or 360
D	60 or 100

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

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	Olivia
B	FSK441
C	JT65
D	PACTOR III

11. - E2E05

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

Select	Answer
A	MFSK
B	Winlink
C	RTTY
D	PSK31

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the MUF is above 30 MHz
B	When the Moon is full
C	When the Moon is at perigee
D	When the Moon is at apogee

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 mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
C	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
D	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves

14. - E3C14

Why does the radio-path horizon distance exceed the geometric horizon?

Select	Answer
A	Downward bending due to aurora refraction
B	Downward bending due to density variations in the atmosphere
C	D-region skip
D	E-region skip

15. - E4A15

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

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

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. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Output-offset overshoot
B	Filter ringing
C	Undesired signals may be heard
D	Thermal-noise distortion

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. - E4E15

Which of the following can cause shielded cables to radiate or receive interference?

Select	Answer
A	Common mode currents on the shield and conductors
B	Low inductance ground connections at both ends of the shield
C	Use of braided shielding material
D	Tying all ground connections to a common point resulting in differential mode currents in the shield

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Fewer components are needed for the same performance
B	Phase shift can become uncontrolled
C	Internal voltages and circulating currents increase
D	Parasitic effects are minimized

21. - E5B09

What is the relationship between the current through a capacitor and the voltage across a capacitor?

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

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical 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. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	0.5
C	1.0
D	0.707

24. - E6A17

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

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

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Zero bias
C	Forward bias
D	Inductive bias

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 feedback loop becomes unstable
C	The comparator enters latch-up
D	The comparator changes its output state

27. - E6D05

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

Select	Answer
A	Ferrite toroids generally have lower initial permeability
B	Ferrite toroids generally require fewer turns to produce a given inductance value
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally have better temperature stability

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	50 ohms
B	300 ohms
C	10 ohms
D	450 ohms

29. - E6F07

What is a solid state relay?

Select	Answer
A	A passive delay line
B	A device that uses semiconductors to implement the functions of an electromechanical relay
C	A relay using transistors to drive the relay coil
D	A mechanical relay that latches in the on or off state each time it is pulsed

30. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the high logic states of an op-amp
B	A list of inputs and corresponding outputs for a digital device
C	A diagram showing logic states when the digital device output is true
D	A table of logic symbols that indicate the logic states of an op-amp

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

32. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
B	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground

33. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A shunt current source
B	A series current source
C	A shunt regulator
D	A series regulator

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	The sum, difference and square root of the input frequencies
C	1.414 and 0.707 times the input frequency
D	Two and four times the original frequency

35. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample clock phase noise
B	Sample width in bits
C	Processor latency
D	Sample rate

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	As a high-pass filter used to block RFI at the input to receivers
C	For smoothing power supply output
D	As an audio filter in a receiver

37. - E7H08

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

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

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	8
B	256 divided by the gain of the input amplifier
C	256
D	8 multiplied by the gain of the input amplifier

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more signals are quadrature modulated to increase bandwidth efficiency
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 arranged to share discrete time slots of a data transmission

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D12

What is the advantage of including a parity bit with an ASCII character stream?

Select	Answer
A	The signal can overpower interfering signals
B	Foreign language characters can be sent
C	Faster transmission rate
D	Some types of errors can be detected SUBELEMENT E9 - ANTENNAS AND TRANSMISSION LINES [8 Exam Questions - 8 Groups] E9A Basic Antenna parameters: radiation resistance, gain, beamwidth, efficiency, beamwidth; effective radiated power, polarization E9A01 (C) What describes an isotropic antenna? A. A grounded antenna used to measure earth conductivity B. A horizontally polarized antenna used to compare Yagi antennas C. A theoretical antenna used as a reference for antenna gain D. A spacecraft antenna used to direct signals toward the earth

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Distance from the transmitter
B	Soil conductivity
C	The standing wave ratio
D	Take-off angle

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
B	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna
C	They are the same
D	The total amount of radiation from the directional antenna is increased by the gain of the antenna

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An end fed dipole antenna
C	An omni-directional antenna commonly used for satellite communications
D	A dipole constructed from zip cord

45. - E9D04

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

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

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 stub match
C	The gamma match
D	The delta 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	The same as the input impedance of the final generator stage
B	A capacitive reactance
C	The same as the characteristic impedance of the line
D	An inductive reactance

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance lines and reactance chords
B	Voltage circles and current arcs
C	Voltage lines and current chords
D	Resistance circles and reactance arcs

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
B	It narrows the bandwidth of the received signal to improve signal to noise ratio
C	It prevents receiver overload which could make it difficult to determine peaks or nulls
D	It compensates for the effects of an isotropic antenna, thereby improving directivity

50. - E0A02

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

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