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

2. - E1B05

What is the National Radio Quiet Zone?

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

3. - E1C06

Which of the following statements concerning remotely controlled amateur stations is true?

Select	Answer
A	Only Extra Class operators may be the control operator of a remote station
B	Repeater and auxiliary stations may not be remotely controlled
C	A control operator need not be present at the control point
D	A control operator must be present at the control point

4. - E1D03

What is a telecommand station in the amateur satellite service?

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

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
B	The person who has entered into an agreement with the FCC to be the VE session manager
C	A person who has volunteered to administer amateur operator license examinations
D	A person who has volunteered to prepare amateur operator license examinations

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. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Radar
B	APRS
C	Bandwidth compressed LORAN
D	Doppler shift of beacon signals

8. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	60
B	30
C	525
D	1080

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A 440 MHz transceiver with a 9600 baud modem
C	An optical cable connection between the USB ports of 2 separate computers
D	A standard wireless router running custom software

10. - E2D07

What digital protocol is used by APRS?

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

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	PACTOR
B	RTTY
C	Hellschreiber
D	AMTOR

12. - E3A15

What is an electromagnetic wave?

Select	Answer
A	A wave consisting of two magnetic fields at right angles to each other
B	A wave consisting of an electric field and a magnetic field oscillating at right angles to each other
C	A wave consisting of two electric fields at parallel right angles to each other
D	A wave of alternating current, in the core of an electromagnet

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

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

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The ratio of X-Ray flux to radio flux, correlated to sunspot number
B	The solar emission at 304 GHz, correlated to X-Ray flare levels
C	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
D	UV emissions at 304 angstroms, correlated to solar flux index

15. - E4A02

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

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

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. - 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	14.755 MHz
B	15.210 MHz
C	14.445 MHz
D	13.845 MHz

18. - E4D13

Which of the following can cause receiver desensitization?

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

19. - E4E01

Which of the following types of receiver noise can often be reduced by use of a receiver noise blanker?

Select	Answer
A	Ignition noise
B	Broadband white noise
C	All of these choices are correct
D	Heterodyne interference

20. - E5A10

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

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

21. - E5B06

What is susceptance?

Select	Answer
A	A measure of the efficiency of a transformer
B	The magnetic impedance of a circuit
C	The inverse of reactance
D	The ratio of magnetic field to electric field

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Near field diagram
B	Far field diagram
C	Venn diagram
D	Phasor diagram

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	355 W
C	704 W
D	252 W

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to base current
B	The change of base current with respect to collector current
C	The change of collector current with respect to emitter current
D	The change of collector current with respect to gate current

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Varactor diode
C	Tunnel diode
D	Silicon-controlled rectifier

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to an op-amp output that only functions when the logic output is false
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor that insures that an oscillator frequency does not drive lower over time

27. - E6D02

What is the equivalent circuit of a quartz crystal?

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

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	450 ohms
B	10 ohms
C	50 ohms
D	300 ohms

29. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It becomes unstable
B	It decreases
C	It increases
D	It stays the same

30. - E7A12

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

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

31. - E7B02

What is a Class D amplifier?

Select	Answer
A	A type of amplifier that uses switching technology to achieve high efficiency
B	An amplifier that uses drift-mode FETs for high efficiency
C	A frequency doubling amplifier
D	A low power amplifier that uses a differential amplifier for improved linearity

32. - E7C09

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

Select	Answer
A	An automatic notch filter
B	A variable bandwidth crystal lattice filter
C	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
D	A special filter that emphasizes image responses

33. - E7D11

What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Select	Answer
A	Reference voltage
B	Switching inductance
C	Error amplifier
D	Pass transistor

34. - E7E11

Which type of detector is used for demodulating SSB signals?

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

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

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The differential input voltage needed to bring the open loop output voltage to zero
B	The potential between the amplifier input terminals of the op-amp in an open loop condition
C	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
D	The output voltage of the op-amp minus its input voltage

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The phase relationship between a reference oscillator and the output waveform
B	The amplitude values that represent a sine-wave output
C	The phase relationship between a voltage-controlled oscillator and the output waveform
D	The synthesizer frequency limits and frequency values stored in the radio memories

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

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
B	A frequency modulation technique which uses non-harmonically related frequencies
C	A digital mode for narrow band, slow speed transmissions
D	A bandwidth compression technique using Fourier transforms

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Gray code
B	Excess 3 code
C	Binary Coded Decimal Code
D	Extended Binary Coded Decimal Interchange Code

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	The receiver is always equipped with a digital blanker
D	If interference is detected by the receiver it will signal the transmitter to change frequencies

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Distance from the transmitter
B	Take-off angle
C	Soil conductivity
D	The standing wave ratio

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	7
B	3
C	4
D	1

44. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus rocky ground?

Select	Answer
A	The low-angle radiation increases
B	Both the high-angle and low-angle radiation decrease
C	The low-angle radiation decreases
D	The high-angle radiation increases

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain increases by 6 dB
B	Gain is multiplied by 0.707
C	Gain does not change
D	Gain increases by 3 dB

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

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

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Beam headings and radiation patterns
B	Satellite azimuth and elevation bearings
C	Impedance and SWR values in transmission lines
D	Trigonometric functions

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	The geometric angles of sky waves from the source are used to determine its position
B	Antenna headings from several different receiving locations are used to locate the signal source
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. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RF current flow between pieces of equipment
B	Reduce received noise
C	Lightning protection
D	Reduce RFI to telephones and home entertainment systems

Figure E9-2