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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	12 meter band
B	60 meter band
C	17 meter band
D	30 meter band

2. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Only those club stations licensed to Amateur Extra class operators
B	Any FCC-licensed amateur station except a Technician class
C	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

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

4. - E1D05

What class of licensee is authorized to be the control operator of a space station?

Select	Answer
A	Any class with appropriate operator privileges
B	Only Amateur Extra Class
C	All except Technician Class
D	Only General, Advanced or Amateur Extra Class

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 80%
B	Minimum passing score of 70%
C	Minimum passing score of 77%
D	Minimum passing score of 74%

6. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When the control operator is employed by the FCC or another government agency
C	When transmitting international third-party communications
D	When neither the amateur nor his or her employer has a pecuniary interest in the communications

7. - E2A11

What type of antenna can be used to minimize the effects of spin modulation and Faraday rotation?

Select	Answer
A	A circularly polarized antenna
B	A linearly polarized antenna
C	A log-periodic dipole array
D	An isotropic antenna

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	180 or 360
B	128 or 256
C	60 or 100
D	30 or 60

9. - E2C08

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

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

10. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	High speed CW identification to avoid fading
B	Time synchronous transmissions alternately from each station
C	Judging optimum transmission times by monitoring beacons reflected from the Moon
D	Storing and forwarding digital messages

11. - E2E06

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

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

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The D layer
B	The E layer
C	The F2 layer
D	The F1 layer

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become phase-locked
C	They become elliptically polarized
D	Their polarization is randomly modified

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	Polar paths
B	NVIS
C	Sporadic-E
D	Transequatorial propagation

15. - E4A08

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

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

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	1.4652 MHz
D	165.2 Hz

17. - E4C12

What is an undesirable effect of using too wide a filter bandwidth in the IF section of a receiver?

Select	Answer
A	Filter ringing
B	Output-offset overshoot
C	Thermal-noise distortion
D	Undesired signals may be heard

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Raise the receiver IF frequency
B	Increase the receiver front end gain
C	Decrease the RF bandwidth of the receiver
D	Switch from fast AGC to slow AGC

19. - E4E10

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

Select	Answer
A	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
B	The interfering signal may drift slowly across the HF spectrum
C	All of these choices are correct
D	The interfering signal can be several kHz in width and usually repeats at regular intervals across a HF band

20. - E5A09

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

Select	Answer
A	Reactance of either the inductance or capacitance multiplied by the resistance
B	Reactance of either the inductance or capacitance divided 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. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	14 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	76 degrees with the voltage leading the current
D	76 degrees with the voltage lagging the current

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

Select	Answer
A	A positive real part
B	A negative phase angle
C	A negative real part
D	A positive phase angle

23. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor decrease the impedance
C	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
D	Thermal effects on the surface of the conductor increase the impedance

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

25. - E6B13

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

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

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
B	All of these choices are correct
C	Its simplicity results in much less expensive devices than standard CMOS
D	It is totally immune to electrostatic damage

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	35 turns
B	141 turns
C	13 turns
D	79 turns

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	44 dBm
B	-20 dBm
C	-10 dB
D	2 dB

29. - E6F07

What is a solid state relay?

Select	Answer
A	A passive delay line
B	A relay using transistors to drive the relay coil
C	A mechanical relay that latches in the on or off state each time it is pulsed
D	A device that uses semiconductors to implement the functions of an electromechanical relay

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic "1" at its output if any single input is logic "1"
B	It produces logic "1" at its output only if all inputs are logic "1"
C	It produces logic "0" at its output if any single input is logic "1"
D	It produces logic "0" at its output only if all inputs are logic "0"

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A high-pass filter to compensate for low gain at low frequencies
B	A temperature compensating load resistor to improve linearity
C	A matched load resistor to prevent damage by switching transients
D	A low-pass filter to remove switching signal components

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	A variable bandwidth crystal lattice filter
B	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter
C	A special filter that emphasizes image responses
D	An automatic notch filter

33. - E7D10

What is the primary reason that a high-frequency switching type high voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	It uses a diode bridge rectifier for increased output
C	It uses a large power factor compensation capacitor to create free power from the unused portion of the AC cycle
D	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output

34. - E7E06

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

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

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Combine signals with a quadrature phase relationship
B	Emulation of quartz crystal filter characteristics
C	A frequency synthesizer removes the unwanted sidebands
D	Mixing products are converted to voltages and subtracted by adder circuits

36. - E7G05

How can unwanted ringing and audio instability be prevented in a multi-section op-amp RC audio filter circuit?

Select	Answer
A	Increase both gain and Q
B	Restrict gain but increase Q
C	Restrict Q but increase gain
D	Restrict both gain and Q

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Frequency synthesis, FM demodulation
C	Comparison of two digital input signals, digital pulse counter
D	Wide-band AF and RF power amplification

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	1 to 1
B	25 to 1
C	2.5 to 1
D	100 to 1

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	0.47
B	2.14
C	47
D	0.214

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It facilitates error detection
B	It has more resolution than simple binary
C	It increases security
D	It has more possible states than simple binary

41. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code
C	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
D	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Quarter-wave vertical
B	Half-wave dipole
C	Yagi
D	Isotropic antenna

43. - E9B02

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

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

44. - E9C14

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

Select	Answer
A	The main lobe takeoff angle decreases in the downhill direction
B	The horizontal beam width decreases in the downhill direction
C	The main lobe takeoff angle increases in the downhill direction
D	The horizontal beam width increases in the uphill direction

45. - E9D02

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

Select	Answer
A	Stack two Yagis fed in 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 90 degrees out of 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. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The gamma match
B	The stub match
C	The delta match
D	The omega match

47. - E9F15

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

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

48. - E9G05

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

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

49. - E9H09

Which of the following describes the construction of a receiving loop antenna?

Select	Answer
A	One or more turns of wire wound in the shape of a large open coil
B	A large circularly polarized antenna
C	A small coil of wire tightly wound around a toroidal ferrite core
D	A vertical antenna coupled to a feed line through an inductive loop of wire

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only commercial transmitters
B	Each transmitter operating with a duty-cycle greater than 50 percent
C	Only the most powerful transmitter
D	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations

Figure E9-1

Figure E9-3