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

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1. - E1A09

What is the first action you should take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Discontinue forwarding all messages
C	Discontinue forwarding the communication as soon as you become aware of it
D	Notify the nearest FCC Field Engineer's office

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area surrounding the National Radio Astronomy Observatory
B	An area in New Mexico surrounding the White Sands Test Area
C	An area in Florida surrounding Cape Canaveral
D	An area in Puerto Rico surrounding the Arecibo Radio Telescope

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, beacon or space stations
C	Only auxiliary, repeater or space stations
D	Only earth stations, repeater stations or model craft

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
B	All of these choices are correct
C	Any amateur station so designated by the ITU
D	Any amateur station designated by NASA

5. - E1E02

Where are the questions for all written U.S. amateur license examinations listed?

Select	Answer
A	In a question pool maintained by the FCC
B	In a question pool maintained by all the VECs
C	In the appropriate FCC Report and Order
D	In FCC Part 97

6. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have a religious content
B	Communications transmitted for hire or material compensation, except as otherwise provided in the rules
C	Communications in a language other than English
D	Communications that have a political content, except as allowed by the Fairness Doctrine

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To prevent the satellite from emitting out-of-band signals
B	To avoid reducing the downlink power to all other users
C	To avoid interfering with terrestrial QSOs
D	To prevent creating errors in the satellite telemetry

8. - E2B17

What is the approximate bandwidth of a slow-scan TV signal?

Select	Answer
A	2 MHz
B	600 Hz
C	6 MHz
D	3 kHz

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Repeater contacts between U.S. club members
B	Contacts using tactical call signs
C	Special event contacts between stations in the U.S.
D	Contacts between a U.S. station and a non-U.S. station

10. - E2D01

Which of the following digital modes is especially designed for use for meteor scatter signals?

Select	Answer
A	APRS
B	Hellschreiber
C	WSPR
D	FSK441

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	RTTY
B	MT63
C	PSK31
D	PACTOR

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	Electric and magnetic fields become aligned as they travel
B	The energy propagates through a medium with a high refractive index
C	Changing electric and magnetic fields propagate the energy
D	The waves are reflected by the ionosphere and return to their source

13. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Morning
C	Noon
D	Late at night

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	Transequatorial propagation
B	Sporadic-E
C	NVIS
D	Polar paths

15. - E4A15

What is an advantage of a period-measuring frequency counter over a direct-count type?

Select	Answer
A	It can directly measure the modulation index of an FM transmitter
B	It does not require an expensive high-precision time base
C	It provides improved resolution of low-frequency signals within a comparable time period
D	It can run on battery power for remote measurements

16. - E4B03

If a frequency counter with a specified accuracy of +/- 1.0 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	146.52 Hz
B	14.652 kHz
C	165.2 Hz
D	1.4652 MHz

17. - E4C14

What transmit frequency might generate an image response signal in a receiver tuned to 14.300 MHz and which uses a 455 kHz IF frequency?

Select	Answer
A	13.845 MHz
B	14.445 MHz
C	15.210 MHz
D	14.755 MHz

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Intermodulation interference
B	Adjacent channel interference
C	Amplifier desensitization
D	Neutralization

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By installing a high pass filter in series with the motor's power leads
C	By using a ground-fault current interrupter in the circuit used to power the motor
D	By installing a bypass capacitor in series with the motor leads

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Internal voltages and circulating currents increase
B	Phase shift can become uncontrolled
C	Parasitic effects are minimized
D	Fewer components are needed for the same performance

21. - E5B13

What letter is commonly used to represent susceptance?

Select	Answer
A	G
B	B
C	X
D	Y

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 7
B	Point 1
C	Point 3
D	Point 8

23. - E5D08

What type of energy is stored in an electromagnetic or electrostatic field?

Select	Answer
A	Kinetic energy
B	Electromechanical energy
C	Potential energy
D	Thermodynamic energy

24. - E6A17

What are the names of the three terminals of a field-effect transistor?

Select	Answer
A	Gate 1, gate 2, drain
B	Emitter, base, collector
C	Gate, drain, source
D	Emitter, base 1, base 2

25. - E6B13

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Zero bias
C	Inductive bias
D	Forward bias

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	More efficient arithmetic operations
B	Low power consumption
C	High speed operation
D	Ability to connect many device outputs to a common bus

27. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
B	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance
C	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Microstrip construction
B	Point-to-point construction
C	Ground-plane construction
D	Wave-soldering construction

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A display that uses a glowing liquid to remain brightly lit in dim light
B	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
C	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
D	A frequency-determining unit for a transmitter or receiver

30. - E7A12

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

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

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Switching amplifiers use push-pull circuits
B	The power transistor is at saturation or cut off most of the time, resulting in low power dissipation
C	Switching amplifiers operate at higher voltages
D	Linear amplifiers have high gain resulting in higher harmonic content

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

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	To self-resonate at the hum frequency
B	It is a brute force filter for the output
C	To provide fixed DC bias for Q1
D	It bypasses hum around D1

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a balanced modulator followed by a filter
B	By driving a product detector with a DSB signal
C	By using a loop modulator followed by a mixer
D	By using a reactance modulator followed by a mixer

35. - E7F15

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters are easier to implement for a given set of passband rolloff requirements
B	All of these choices are correct
C	FIR filters can respond faster to impulses
D	FIR filters delay all frequency components of the signal by the same amount

36. - E7G03

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

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

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

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

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A sawtooth wave
B	A sine wave
C	A cosine wave
D	A square wave

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	60
B	0.6
C	0.167
D	1.67

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Symbol rate is only used for packet-based modes
B	Baud is only used for RTTY
C	They are the same
D	Baud is twice the symbol rate

41. - E8D04

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

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

42. - E9A08

What is meant by antenna bandwidth?

Select	Answer
A	The angle formed between two imaginary lines drawn through the element ends
B	The frequency range over which an antenna satisfies a performance requirement
C	Antenna length divided by the number of elements
D	The angle between the half-power radiation points

43. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Mutual impedance analysis
B	Method of Moments
C	Calculus differentiation with respect to physical properties
D	Graphical analysis

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The horizontal beam width increases with height
B	The main lobe takeoff angle increases with increasing height
C	The main lobe takeoff angle decreases with increasing height
D	The horizontal beam width decreases with height

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	It becomes flat
B	It is decreased
C	No change occurs
D	It is increased

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. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.30
B	2.70
C	0.10
D	0.66

48. - E9G05

What type of chart is shown in Figure E9-3?

Select	Answer
A	Free space radiation directivity chart
B	Elevation angle radiation pattern chart
C	Azimuth angle radiation pattern chart
D	Smith chart

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By increasing either the number of wire turns in the loop or the area of the loop structure or both
B	By increasing the number of wire turns in the loop and reducing the area of the loop structure
C	By winding adjacent turns in opposing directions
D	By reducing the permeability of the loop shield

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polyethylene
B	Polytetrafluroethylene
C	Polymorphic silicon
D	Polychlorinated Biphenyls

Figure E5-2

Figure E7-3

Figure E9-3