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

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1. - E1A13

Who must be in physical control of the station apparatus of an amateur station aboard any vessel or craft that is documented or registered in the United States?

Select	Answer
A	Only a person named in an amateur station license grant
B	Only a person with an FCC Marine Radio
C	Any person holding an FCC issued amateur license or who is authorized for alien reciprocal operation
D	Any person named in an amateur station license grant or a person holding an unrestricted Radiotelephone Operator Permit

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
B	The amateur station must cease operation
C	The amateur station must cease operation on all frequencies above 30 MHz
D	The amateur station must cease operation on all frequencies below 30 MHz

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled indirectly through a control link
B	A station operating under automatic control
C	A station operated away from its regular home location
D	A station controlled by someone other than the licensee

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters
C	2 meters and 1.25 meters
D	6 meters, 2 meters, and 1.25 meters

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	All of these choices are correct
C	Relatives of the VE as listed in the FCC rules
D	Employees of the VE

6. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and north of the U.S.-Mexican border and Gulf coastline
B	A line roughly parallel to and west of the U.S. Atlantic coastline
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and south of the U.S.-Canadian border

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	PSK and Packet
B	All of these choices are correct
C	FM and CW
D	SSB and SSTV

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	Sync frequency
D	Tone frequency

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

10. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	PACTOR
B	AX.25
C	802.11
D	AMTOR

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	31 Hz
B	2.16 kHz
C	550 Hz
D	316 Hz

12. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

Select	Answer
A	500 miles, if the Moon is at perigee
B	5000 miles, if the Moon is at perigee
C	2000 miles, if the Moon is at apogee
D	12,000 miles, if the Moon is visible by both stations

13. - E3B09

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

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

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	Modeling a radio wave's path through the ionosphere
C	Determining the radiation pattern from an array of antennas
D	The process in which an electronic display presents a pattern

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A time-domain reflectometer
B	A spectrum analyzer
C	A logic analyzer
D	A wattmeter

16. - E4B02

What is an advantage of using a bridge circuit to measure impedance?

Select	Answer
A	It is very precise in obtaining a signal null
B	It is relatively immune to drift in the signal generator source
C	It provides an excellent match under all conditions
D	It can display results directly in Smith chart format

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-155 dBm
B	-174 dBm
C	-148 dBm
D	-164 dBm

18. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	The third-order intercept is much higher than other orders
B	Third-order products are an indication of poor image rejection
C	The third-order product of two signals which are in the band of interest is also likely to be within the band
D	Third-order intermodulation produces three products for every input signal within the band of interest

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	Your station receiver IF amplifier stage is defective
B	The broadcast station is transmitting an over-modulated signal
C	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
D	You are receiving sky wave signals from a distant station

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance times the reactance of the capacitance
C	Reactance of either the inductance or capacitance times the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

21. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage?

Select	Answer
A	An exponential rate of one
B	One time constant
C	A time factor of one
D	One exponential period

22. - E5C07

What is a vector?

Select	Answer
A	A quantity with both magnitude and an angular component
B	The inverse of the tangent function
C	The value of a quantity that changes over time
D	The inverse of the sine function

23. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By dividing the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By multiplying the apparent power times the power factor
D	By multiplying the reactive power times the power factor

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter resistance of approximately 6 to 7 ohms
D	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms

25. - E6B12

What is one common use for PIN diodes?

Select	Answer
A	As a constant current source
B	As a high voltage rectifier
C	As a constant voltage source
D	As an RF switch

26. - E6C02

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

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

27. - E6D08

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

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

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	Its phase shift changes rapidly with frequency
B	It is a CMOS analog-to-digital converter
C	It is used in a battery charger circuit
D	It samples an analog signal and passes it in stages from the input to the output

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide impedance matching between the control circuit and power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

30. - E7A12

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

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

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Emitter follower
B	Common base
C	Common collector
D	Common emitter

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are designed for balanced input and output
B	L-networks cannot perform impedance transformation
C	The Q of Pi-networks can be varied depending on the component values chosen
D	Pi-networks have fewer components

33. - E7D11

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

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

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	For compatibility with transmitters using phase modulation
C	For higher efficiency
D	To remove third-order distortion products

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An adaptive filter
C	A phase-inverting filter
D	A crystal-lattice filter

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	76
B	0.03
C	1
D	38

37. - E7H08

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

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

38. - E8A11

What type of information can be conveyed using digital waveforms?

Select	Answer
A	Human speech
B	Data
C	All of these choices are correct
D	Video signals

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	47
B	2.14
C	0.214
D	0.47

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	5.76 kHz
B	9.6 kHz
C	4.8 kHz
D	15.36 kHz

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Frequency hopping
B	Phase compandored spread spectrum
C	Direct sequence
D	Binary phase-shift keying

42. - E9A15

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	78.7 watts
B	420 watts
C	1977 watts
D	286 watts

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Next Element Comparison
B	Numerical Electromagnetic Code
C	National Electrical Code
D	Numeric Electrical Computation

44. - E9C10

Which of the following describes a Zepp antenna?

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

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. - E9E04

What is the purpose of the series capacitor in a gamma-type antenna matching network?

Select	Answer
A	To transform the antenna impedance to a higher value
B	To provide a rejection notch that prevents the radiation of harmonics
C	To cancel the inductive reactance of the matching network
D	To provide DC isolation between the feed line and the antenna

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	71 meters
B	15 meters
C	10 meters
D	20 meters

48. - E9G10

What do the arcs on a Smith chart represent?

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

49. - E9H07

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

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

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	Use an antenna modeling program to calculate field strength at accessible locations
B	All of the choices are correct
C	Use a hand calculator plus Smith-chart equations to calculate the fields
D	Use a calibrated antenna analyzer

Figure E7-1

Figure E7-4