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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
B	No, one of the sidebands of the CW signal will be out of the band
C	Yes, the displayed frequency is within the 80 meter CW band segment
D	Yes, the DX station initiated the contact

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	30 miles
B	1 mile
C	3 miles
D	10 miles

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	All of these choices are correct
C	Messages intended for connection to users of the maritime satellite service
D	Communications incidental to the purpose of the amateur service and remarks of a personal nature

4. - E1D09

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

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

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	All of these choices are correct
B	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
C	A sentence of up to one year in prison
D	A fine of up to $1000 per occurrence

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 that have a religious content
C	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
D	Communications in a language other than English

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	APRS
B	Bandwidth compressed LORAN
C	Radar
D	Doppler shift of beacon signals

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	All of these choices are correct
B	Frequency modulation of the video carrier
C	Frequency-modulated sub-carrier
D	A separate VHF or UHF audio link

9. - E2C07

What is the Cabrillo format?

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

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	PSK
B	RTTY
C	IEEE 802.11
D	Multi-tone AFSK

11. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	1200 baud
B	300 baud
C	110 baud
D	48 baud

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Dust devil
B	The jet stream
C	Temperature inversion
D	Wind shear

13. - E3B11

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

Select	Answer
A	Around sunset
B	Any time
C	Early evening
D	Around sunrise

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	Sporadic-E
B	NVIS
C	Polar paths
D	Transequatorial propagation

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

16. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Temperature coefficient of the logic
B	Input attenuator accuracy
C	Decade divider accuracy
D	Time base accuracy

17. - E4C02

Which of the following portions of a receiver can be effective in eliminating image signal interference?

Select	Answer
A	A properly adjusted product detector
B	A notch filter
C	A front-end filter or pre-selector
D	A narrow IF filter

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

19. - E4E10

What is a common characteristic of interference caused by a touch controlled electrical device?

Select	Answer
A	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band
B	The interfering signal sounds like AC hum on an AM receiver or a carrier modulated by 60 Hz hum on a SSB or CW receiver
C	The interfering signal may drift slowly across the HF spectrum
D	All of these choices are correct

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance
B	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C
C	It is at a minimum
D	It is at a maximum

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

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Elliptical coordinates
B	Maidenhead grid
C	Rectangular coordinates
D	Faraday grid

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	0.5
C	0.866
D	1.73

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that has no current flow between source and drain when no gate voltage is applied
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	Any FET without a channel
D	Any FET for which holes are the majority carriers

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Ability to dissipate large amounts of power
B	Reverse bias controls its forward voltage drop
C	Extremely high reverse breakdown voltage
D	A large region of intrinsic material

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. - E6D01

How many turns will be required to produce a 5-microhenry inductor using a powdered-iron toroidal core that has an inductance index (A L) value of 40 microhenrys/100 turns?

Select	Answer
A	13 turns
B	141 turns
C	79 turns
D	35 turns

28. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	Plate current that is controlled by a control grid
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	The ability to retrieve information from a single signal even in the presence of other strong signals
D	Nearly infinite gain, very high input impedance, and very low output impedance

29. - E6F01

What is photoconductivity?

Select	Answer
A	The conversion of electromotive energy to photon energy
B	The decreased conductivity of an illuminated semiconductor
C	The conversion of photon energy to electromotive energy
D	The increased conductivity of an illuminated semiconductor

30. - E7A10

What is a truth table?

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Emitter load
B	Collector load
C	Voltage regulation
D	Fixed bias

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A notch filter
B	A band-pass filter
C	An all-pass filter
D	A Pi-network filter

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 shunt regulator
C	A series regulator
D	A series current source

34. - E7E08

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

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

35. - E7F17

What do the letters I and Q in I/Q Modulation represent?

Select	Answer
A	In-phase and Quadrature
B	Instantaneous and Quenched
C	Inactive and Quiescent
D	Instantaneous and Quasi-stable

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	As an audio filter in a receiver
D	For smoothing power supply output

37. - E7H08

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

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

38. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	All of these choices are correct
B	Very low power consumption decreases frequency drift
C	Immunity to out of sequence coding reduces spurious responses
D	Very high speed allows digitizing high frequencies

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow band, slow speed transmissions
B	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
C	A frequency modulation technique which uses non-harmonically related frequencies
D	A bandwidth compression technique using Fourier transforms

40. - E8C06

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

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

41. - E8D05

What is the most common method of reducing key clicks?

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

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Install a good radial system
B	Isolate the coax shield from ground
C	Shorten the radiating element
D	Reduce the diameter of the radiating element

43. - E9B13

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

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

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

45. - E9D03

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

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

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 stub match
B	The delta match
C	The gamma match
D	The epsilon match

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the output impedance of the generator
B	Very low impedance
C	Very high impedance
D	The same as the characteristic impedance of the line

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The voltage axis
B	The reactance axis
C	The resistance axis
D	The current axis

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Low loss coax transmission line is essential for good performance
B	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	All of these choices are correct
D	Atmospheric noise is so high that gain over a dipole is not important

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Blood clotting from the intense magnetic field
C	Localized heating of the body from RF exposure in excess of the MPE limits
D	Ingestion of ozone gas from the cooling system

Figure E7-2

Figure E9-3