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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
B	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
C	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
D	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is of environmental importance or significant in American history, architecture, or culture
B	The location is of geographical or horticultural importance
C	The location is in an ITU Zone designated for coordination with one or more foreign governments
D	The location is near an area of political conflict

3. - E1C10

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

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

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
B	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
C	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands
D	All HF bands

5. - E1E13

Which of these choices is an acceptable method for monitoring the applicants if a VEC opts to conduct an exam session remotely?

Select	Answer
A	Record the exam session on video tape for later review by the VE team
B	Use a real-time video link and the Internet to connect the exam session to the observing VEs
C	The exam proctor observes the applicants and reports any violations
D	Have each applicant sign an affidavit stating that all session rules were followed

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When the total money involved does not exceed $25
C	When the control operator is employed by the FCC or another government agency
D	When transmitting international third-party communications

7. - E2A02

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

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

8. - E2B12

How are analog SSTV images typically transmitted on the HF bands?

Select	Answer
A	Video is converted to equivalent Baudot representation
B	Varying tone frequencies representing the video are transmitted using single sideband
C	Video is converted to equivalent ASCII representation
D	Varying tone frequencies representing the video are transmitted using PSK

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	A method of exchanging information during a contest QSO
B	A standard for submission of electronic contest logs
C	The most common set of contest rules
D	The rules of order for meetings between contest sponsors

10. - E2D09

Which of these digital modes has the fastest data throughput under clear communication conditions?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	PSK31
C	300 baud packet
D	AMTOR

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

12. - E3A14

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

Select	Answer
A	West
B	South
C	North
D	East

13. - E3B07

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

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

14. - E3C14

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

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

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Modulation monitor
B	Logic analyzer
C	Bit error rate tester
D	Network analyzer

16. - E4B17

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

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

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Fewer components in the receiver
B	Improved receiver noise figure
C	Reduced drift
D	Easier for front-end circuitry to eliminate image responses

18. - E4D07

Which describes the most significant effect of an off-frequency signal when it is causing cross-modulation interference to a desired signal?

Select	Answer
A	A reduction in apparent signal strength
B	The desired signal can no longer be heard
C	The off-frequency unwanted signal is heard in addition to the desired signal
D	A large increase in background noise

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	All of these choices are correct
B	A malfunctioning illuminated advertising display
C	A defective doorbell or doorbell transformer inside a nearby residence
D	Arcing contacts in a thermostatically controlled device

20. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

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

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage lagging the current
C	76 degrees with the voltage leading the current
D	14 degrees with the voltage leading the current

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Phasor diagram
B	Near field diagram
C	Far field diagram
D	Venn diagram

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	252 W
C	1.42 mW
D	355 W

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	Acceptor impurity
C	Donor impurity
D	N-type impurity

25. - E6B04

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	It is totally immune to electrostatic damage
C	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
D	All of these choices are correct

27. - E6D04

Which materials are commonly used as a slug core in a variable inductor?

Select	Answer
A	Polystyrene and polyethylene
B	Ferrite and brass
C	Teflon and Delrin
D	Cobalt and aluminum

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Low leakage doubly insulated package
B	Package mounts in a direct inverted position
C	Two chips in each package (Dual In Package)
D	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	An LED and a phototransistor
B	A frequency modulated helium-neon laser
C	A lens and a photomultiplier
D	An amplitude modulated helium-neon laser

30. - E7A03

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

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

31. - E7B06

Which of the following amplifier types reduces or eliminates even order harmonics?

Select	Answer
A	Class C
B	Push-pull
C	Push-push
D	Class AB

32. - E7C04

How does an impedance-matching circuit transform a complex impedance to a resistive impedance?

Select	Answer
A	Network resistances are substituted for load resistances and reactances are matched to the resistances
B	It introduces negative resistance to cancel the resistive part of impedance
C	It introduces transconductance to cancel the reactive part of impedance
D	It cancels the reactive part of the impedance and changes the resistive part to a desired value

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

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

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce PM signals
B	By varying the tuning of an amplifier tank circuit to produce PM signals
C	By varying the tuning of a microphone preamplifier to produce AM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F07

What function can a Fast Fourier Transform perform?

Select	Answer
A	Converting 8-bit data to 16 bit data
B	Converting analog signals to digital form
C	Converting digital signals to analog form
D	Converting digital signals from the time domain to the frequency domain

36. - E7G03

What is the typical input impedance of an integrated circuit op-amp?

Select	Answer
A	Very low
B	100 ohms
C	Very high
D	1000 ohms

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Frequency synthesis, FM demodulation
C	Wide-band AF and RF power amplification
D	Comparison of two digital input signals, digital pulse counter

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals always occupy a narrower bandwidth
B	All of these choices are correct
C	Less complex circuitry is required for digital signal generation and detection
D	Digital signals can be regenerated multiple times without error

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

40. - E8C06

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

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

41. - E8D11

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

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

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Half-wave dipole
B	Yagi
C	Isotropic antenna
D	Quarter-wave vertical

43. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a uniform value of current
B	A wire is modeled as a single sine-wave current generator
C	A wire is modeled as a series of points, each having a distinct location in space
D	A wire is modeled as a series of segments, each having a distinct value of voltage across it

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	72 ohms
B	450 ohms
C	300 ohms
D	50 ohms

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	At a voltage node
B	Near the center of the vertical radiator
C	As low as possible on the vertical radiator
D	As close to the transmitter as possible

46. - E9E01

What system matches a higher impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The delta matching system
B	The gamma matching system
C	The stub matching system
D	The omega matching system

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Surge impedance
B	Velocity factor
C	Characteristic impedance
D	Standing wave ratio

48. - E9G02

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be configured as a four-sided loop
B	It should be one or more wavelengths long
C	It must be mounted more than 1 wavelength above ground
D	Its overall length must not exceed 1/4 wavelength

50. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	All of these choices are correct
B	Ground reflections and scattering make the field impedance vary with location
C	E field and H field radiation intensity peaks can occur at different locations
D	The body reacts to electromagnetic radiation from both the E and H fields