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

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1. - E1A14

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	2.8 kHz
C	1.5 kHz
D	60 Hz

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

3. - E1C07

What is meant by local control?

Select	Answer
A	Controlling a repeater using a portable handheld transceiver
B	Controlling a station through a local auxiliary link
C	Direct manipulation of the transmitter by a control operator
D	Automatically manipulating local station controls

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
B	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
C	An amateur station located more than 50 km above the Earth's surface
D	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites

5. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Maintain the application form with the VEC's records
B	Return the application document to the examinee
C	Send the application form to the FCC and inform the FCC of the grade
D	Destroy the application form

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Technician, General, Advanced or Amateur Extra Class operators
B	Only General, Advanced or Amateur Extra Class operators
C	Only Amateur Extra Class operators
D	Any licensed amateur operator

7. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because of the satellite's low orbital altitude
B	Because of the Doppler Effect
C	Because of ionospheric absorption
D	Because the satellite is spinning

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	60 or 100
C	30 or 60
D	180 or 360

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To improve operating efficiency by reducing interference
B	All of these choices are correct
C	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
D	To separate the calling stations from the DX station

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	All of these choices are correct
B	15 second timed transmission sequences with stations alternating based on location
C	Use of high speed CW or digital modes
D	Short transmission with rapidly repeated call signs and signal reports

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

12. - E3A10

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

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

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
B	Independent waves created in the ionosphere that are elliptically polarized
C	Long path and short path waves
D	Refracted rays and reflected waves

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 50 percent of the distance
B	By approximately twice the distance
C	By approximately four times the distance
D	By approximately 15 percent of the distance

15. - E4A08

Which of the following instrument would be best for measuring the SWR of a beam antenna?

Select	Answer
A	A spectrum analyzer
B	An antenna analyzer
C	An ohmmeter
D	A Q meter

16. - E4B17

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

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

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 narrow IF filter
C	A notch filter
D	A front-end filter or pre-selector

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Squelch gain misadjusted
B	Strong adjacent channel signals
C	Audio gain adjusted too low
D	Audio bias adjusted too high

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

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	22.36 MHz
B	44.72 MHz
C	1.78 MHz
D	3.56 MHz

21. - E5B05

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

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

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	-jX
B	+jX
C	X
D	Omega

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	1.42 mW
B	252 W
C	704 W
D	355 W

24. - E6A14

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has high input impedance; a bipolar transistor has low input impedance
B	They are both high impedance
C	An FET has low input impedance; a bipolar transistor has high input impedance
D	They are both low impedance

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Less forward voltage drop
B	Enhanced carrier retention time
C	Much higher reverse voltage breakdown
D	Controlled reverse avalanche voltage

26. - E6C11

In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	2
B	5
C	6
D	4

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores have lower Q characteristics
B	Toroidal cores make it easier to couple the magnetic energy into other components
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	SOT
C	DIP
D	Ball grid array

29. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The tendency of a battery to discharge when used outside
B	The conversion of light to electrical energy
C	The conversion of voltage to current when exposed to light
D	The conversion of electrical energy to mechanical energy

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

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Neutralization
B	Select transistors with high beta
C	All of these choices are correct
D	Use a resistor in series with the emitter

32. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A passive op-amp filter
B	An active LC filter
C	A Butterworth filter
D	A Chebyshev filter

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	A varactor diode
B	A tunnel diode
C	A Zener diode
D	An SCR

34. - E7E11

Which type of detector is used for demodulating SSB signals?

Select	Answer
A	Product detector
B	Phase comparator
C	Phase detector
D	Discriminator

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Multiply each sample value by a factor of 3/4
B	Add 3 to each input value and subtract 4 from each output value
C	Interpolate by a factor of three, then decimate by a factor of four
D	Change the gain by a factor of 3/4

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It decreases logarithmically with increasing frequency
B	It does not vary with frequency
C	It increases linearly with increasing frequency
D	It decreases linearly with increasing frequency

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit consisting of a precision push-pull amplifier with a differential input
B	An electronic circuit also known as a monostable multivibrator
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator

38. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The degree of carrier suppression
B	The amplifier gain
C	The frequency of the modulating signal
D	The characteristics of the modulating signal

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It decreases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	This results in the least possible transmitted bandwidth for the particular mode
B	All of these choices are correct
C	It is easier to demodulate with a conventional, non-synchronous detector
D	It improves carrier suppression

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	The generation of RF harmonics
C	Limits data speed
D	More difficult to copy

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It increases arithmetically
B	It increases geometrically
C	It is essentially unaffected
D	It decreases

43. - E9B03

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-side ratio?

Select	Answer
A	14 dB
B	24 dB
C	18 dB
D	12 dB

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It changes the impedance angle of the matching network
B	It reduces low-angle radiation
C	It reduces losses in the radiating portion of the antenna
D	It causes increased SWR

45. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
C	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

46. - E9E05

How must the driven element in a 3-element Yagi be tuned to use a hairpin matching system?

Select	Answer
A	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
B	The driven element resonance must be lower than the operating frequency
C	The driven element reactance must be inductive
D	The driven element reactance must be capacitive

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

48. - E9G07

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	Antenna headings from several different receiving locations are used to locate the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station plots three headings to the signal source

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Only with a carbon monoxide detector
B	By the odor
C	Any ordinary smoke detector can be used
D	By the yellowish appearance of the gas

Figure E6-5

Figure E9-1

Figure E9-3