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	2.8 kHz
B	1.5 kHz
C	170 Hz
D	60 Hz

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

3. - E1C01

What is a remotely controlled station?

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

4. - E1D08

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

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

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

6. - E1F04

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

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

7. - E2A10

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

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

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	A two-tone signal
B	Specific tone amplitudes
C	Elapsed time
D	Specific tone frequencies

9. - E2C07

What is the Cabrillo format?

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

10. - E2D07

What digital protocol is used by APRS?

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

11. - E2E05

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

Select	Answer
A	RTTY
B	Winlink
C	PSK31
D	MFSK

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Lightning discharges
B	Warm and cold fronts
C	Gray-line
D	Sprites and jets

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two continents by way of ducts along the magnetic equator
B	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
C	Propagation between two stations at the same latitude
D	Propagation between any two points located on the magnetic equator

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Modeling a radio wave's path through the ionosphere
B	The process in which an electronic display presents a pattern
C	Determining the radiation pattern from an array of antennas
D	Evaluating high voltage sources for X-Rays

15. - E4A04

What determines the upper frequency limit for a computer soundcard-based oscilloscope program?

Select	Answer
A	Amount of memory on the soundcard
B	Analog-to-digital conversion speed of the soundcard
C	All of these choices are correct
D	Q of the interface of the interface circuit

16. - E4B01

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

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

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	4.8 kHz
B	2.4 kHz
C	4.2 kHz
D	1 kHz

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

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Solar radio frequency emissions
C	Geomagnetic storms
D	Meteor showers

20. - E5A09

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

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

21. - E5B05

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

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

22. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what does the horizontal axis represent?

Select	Answer
A	The difference between the resistive and reactive components
B	Reactive component
C	The sum of the reactive and resistive components
D	Resistive component

23. - E5D13

How much power is consumed in a circuit consisting of a 100 ohm resistor in series with a 100 ohm inductive reactance drawing 1 ampere?

Select	Answer
A	200 Watts
B	141.4 Watts
C	100 Watts
D	70.7 Watts

24. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The frequency at which the current gain is reduced to 1
B	The switching speed of the transistor
C	The breakdown voltage of the base to collector junction
D	The change in collector current with respect to base current

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	A sub-harmonic pump signal
B	Forward DC bias current
C	Capacitance of an RF coupling capacitor
D	Reverse voltage larger than the RF signal

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

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

28. - E6E12

Why are high-power RF amplifier ICs and transistors sometimes mounted in ceramic packages?

Select	Answer
A	To provide a low-pass frequency response
B	Enhanced sensitivity to light
C	High-voltage insulating ability
D	Better dissipation of heat

29. - E6F11

What is the approximate open-circuit voltage produced by a fully-illuminated silicon photovoltaic cell?

Select	Answer
A	1.5 V
B	0.1 V
C	0.5 V
D	12 V

30. - E7A12

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

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

31. - E7B13

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

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

32. - E7C08

Which of the following factors has the greatest effect in helping determine the bandwidth and response shape of a crystal ladder filter?

Select	Answer
A	The gain of the RF stage preceding the filter
B	The DC voltage applied to the quartz crystal
C	The relative frequencies of the individual crystals
D	The amplitude of the signals passing through the filter

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 constant current source
C	A shunt regulator
D	A series regulator

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	A circuit for filtering two closely adjacent signals
C	An FM generator circuit
D	A circuit for detecting FM signals

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At four times the rate of the highest frequency component of the signal
B	At twice the rate of the highest frequency component of the signal
C	At half the rate of the highest frequency component of the signal
D	At the same rate as the highest frequency component of the signal

36. - E7G08

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

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

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through a capacitive divider
C	Through link coupling
D	Through a neutralizing capacitor

38. - E8A11

What type of information can be conveyed using digital waveforms?

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

39. - E8B02

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

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

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	15.36 kHz
C	4.8 kHz
D	9.6 kHz

41. - E8D04

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

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

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	Reduce the diameter of the radiating element
C	Shorten the radiating element
D	Isolate the coax shield from ground

43. - E9B02

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

Select	Answer
A	14 dB
B	18 dB
C	36 dB
D	24 dB

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

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

45. - E9D04

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

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

46. - E9E04

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

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

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

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radiation resistance
B	Antenna radiation pattern
C	Radio propagation
D	Impedance along transmission lines

49. - E9H02

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

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

50. - E0A08

What does SAR measure?

Select	Answer
A	The rate at which RF energy is absorbed by the body
B	The rate of RF energy reflected from stationary terrain
C	Signal Amplification Rating
D	Synthetic Aperture Ratio of the human body

Figure E7-2

Figure E9-1