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

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1. - E1A03

With your transceiver displaying the carrier frequency of phone signals, you hear a station calling CQ on 14.349 MHz USB. Is it legal to return the call using upper sideband on the same frequency?

Select	Answer
A	No, U.S. stations are not permitted to use phone emissions above 14.340 MHz
B	Yes, because the displayed frequency is within the 20 meter band
C	Yes, because you were not the station calling CQ
D	No, the sideband will extend beyond the band edge

2. - E1B05

What is the National Radio Quiet Zone?

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

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

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Any amateur station, subject to the privileges of the class of operator license held by the control operator
B	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau
C	Only those of General, Advanced or Amateur Extra Class operators
D	Only those of Amateur Extra Class operators

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 74%
D	Minimum passing score of 77%

6. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To allow regular operation on Land Mobile channels
B	To provide additional spectrum for personal use
C	To provide temporary operation while awaiting normal licensing
D	To provide for experimental amateur communications

7. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From south to north
B	From west to east
C	From north to south
D	From east to west

8. - E2B19

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	They are restricted to phone band segments and their bandwidth can be no greater than that of a voice signal of the same modulation type
B	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
C	None; they are allowed on all amateur frequencies
D	They are not permitted above 54 MHz

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Multiple Frequency Shift Keying in the 10 GHz band
B	Store and forward on the 440 MHz band
C	Spread spectrum in the 2.4 GHz band
D	Frequency division multiplex in the 24 GHz band

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	Uses only a 65 Hz bandwidth
B	Permits fast-scan TV transmissions over narrow bandwidth
C	Easily copied by ear if necessary
D	The ability to decode signals which have a very low signal to noise ratio

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	The receiver has drifted 5 kHz from the desired receive frequency
C	Selective fading has occurred
D	The mark and space signal have been inverted

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 F2 layer
C	The E layer
D	The F1 layer

13. - E3B10

What is the cause of gray-line propagation?

Select	Answer
A	In darkness, solar absorption drops greatly while atmospheric ionization remains steady
B	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
C	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
D	At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	50 percent greater
B	Twice as great
C	10 percent greater
D	Four times as great

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and frequency
B	RF amplitude and frequency
C	SWR and time
D	RF amplitude and time

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	25 watts
B	100 watts
C	125 watts
D	75 watts

17. - E4C04

How is the noise figure of a receiver defined?

Select	Answer
A	The ratio of the noise bandwidth in Hertz to the theoretical bandwidth of a resistive network
B	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
C	The ratio of atmospheric noise to phase noise
D	The ratio of thermal noise to atmospheric noise

18. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
B	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters
C	When the signals from the transmitters are reflected in phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters

19. - E4E14

What is one type of electrical interference that might be caused by the operation of a nearby personal computer?

Select	Answer
A	The appearance of unstable modulated or unmodulated signals at specific frequencies
B	A clicking noise at intervals of a few seconds
C	A whining type noise that continually pulses off and on
D	A loud AC hum in the audio output of your station receiver

20. - E5A06

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

Select	Answer
A	It is at a maximum
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 equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance

21. - E5B07

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 500 ohms, R is 1 kilohm, and XL is 250 ohms?

Select	Answer
A	14.0 degrees with the voltage lagging the current
B	14.0 degrees with the voltage leading the current
C	68.2 degrees with the voltage leading the current
D	68.2 degrees with the voltage lagging the current

22. - E5C13

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

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

23. - E5D14

What is reactive power?

Select	Answer
A	Wattless, nonproductive power
B	Power consumed in wire resistance in an inductor
C	Power lost because of capacitor leakage
D	Power consumed in circuit Q

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Bipolar
B	Insulated gate
C	N-type
D	P-type

25. - E6B11

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

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

26. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To increase the sensitivity
B	To prevent input noise from causing unstable output signals
C	To allow the comparator to be used with AC input signal
D	To cause the output to change states continually

27. - E6D15

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Excitation current
B	Stabilizing current
C	Direct current
D	Magnetizing current

28. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Package mounts in a direct inverted position
B	Two chips in each package (Dual In Package)
C	Low leakage doubly insulated package
D	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

29. - E6F07

What is a solid state relay?

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

30. - E7A12

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

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

31. - E7B01

For what portion of a signal cycle does a Class AB amplifier operate?

Select	Answer
A	More than 180 degrees but less than 360 degrees
B	Less than 180 degrees
C	Exactly 180 degrees
D	The entire cycle

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be varied depending on the component values chosen
B	Pi-networks have fewer components
C	L-networks cannot perform impedance transformation
D	Pi-networks are designed for balanced input and output

33. - E7D08

What type of circuit is shown in Figure E7-3?

Select	Answer
A	Emitter follower
B	Linear voltage regulator
C	Grounded emitter amplifier
D	Switching voltage regulator

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

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

35. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	Higher data rate
B	Double-precision math routines
C	Complex phasor representations
D	More taps

36. - E7G05

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

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

37. - E7H05

How is positive feedback supplied in a Pierce oscillator?

Select	Answer
A	Through a neutralizing capacitor
B	Through a quartz crystal
C	Through a tapped coil
D	Through link coupling

38. - E8A07

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

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

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	47
B	0.47
C	2.14
D	0.214

40. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The duration of each bit in a message sent over the air
C	The number of control characters in a message packet
D	The rate at which the waveform of a transmitted signal changes to convey information

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	Signals not using the spread spectrum algorithm are suppressed in the receiver
B	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The receiver is always equipped with a digital blanker

42. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	6.0 dB
B	3.85 dB
C	2.79 dB
D	8.15 dB

43. - E9B03

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

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

44. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An end fed dipole antenna
C	An omni-directional antenna commonly used for satellite communications
D	A dipole constructed from zip cord

45. - E9D11

Which of the following types of conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	A single 12 gauge or 10 gauge stainless steel wire
B	A wide flat copper strap
C	A cable with six or seven 18 gauge conductors in parallel
D	A resistive wire, such as spark plug wire

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 delta match
B	The epsilon match
C	The gamma match
D	The stub 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	Very low impedance
C	The same as the characteristic impedance of the line
D	Very high impedance

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of antenna electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical wavelength
D	In fractions of transmission line electrical frequency

49. - E9H06

What is the triangulation method of direction finding?

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

50. - E0A03

Which of the following would be a practical way to estimate whether the RF fields produced by an amateur radio station are within permissible MPE limits?

Select	Answer
A	All of the choices are correct
B	Use a hand calculator plus Smith-chart equations to calculate the fields
C	Use a calibrated antenna analyzer
D	Use an antenna modeling program to calculate field strength at accessible locations

Figure E7-3

Figure E9-1