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

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1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system not authenticating the source from which they accept communications
C	The control operator of the packet bulletin board station
D	The control operators of all the stations in the system

2. - E1B02

Which of the following factors might cause the physical location of an amateur station apparatus or antenna structure to be restricted?

Select	Answer
A	The location is of geographical or horticultural importance
B	The location is in an ITU Zone designated for coordination with one or more foreign governments
C	The location is near an area of political conflict
D	The location is of environmental importance or significant in American history, architecture, or culture

3. - E1C07

What is meant by local control?

Select	Answer
A	Controlling a repeater using a portable handheld transceiver
B	Automatically manipulating local station controls
C	Controlling a station through a local auxiliary link
D	Direct manipulation of the transmitter by a control operator

4. - E1D04

What is an Earth station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurement of upper atmosphere
B	An amateur station that is not able to communicate using amateur satellites
C	Any amateur station on the surface of the Earth
D	An amateur station within 50 km of the Earth's surface intended for communications with amateur stations by means of objects in space

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
B	The prospective VE obtains accreditation from the FCC
C	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
D	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	1 W
B	10 W
C	1.5 W
D	1.5 kW

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	144 MHz - 146 MHz
B	50.0 MHz - 50.2 MHz
C	29.5 MHz - 29.7 MHz
D	435 MHz - 438 MHz

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	PAL
B	DRM
C	Scottie
D	NTSC

9. - E2C12

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a higher frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Switch to a lower frequency HF band
D	Wait 90 minutes or so for the signal degradation to pass

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	All of these choices are correct
B	15 second timed transmission sequences with stations alternating based on location
C	Short transmission with rapidly repeated call signs and signal reports
D	Use of high speed CW or digital modes

11. - E2E10

Which of these digital modes has the narrowest bandwidth?

Select	Answer
A	170 Hz shift, 45 baud RTTY
B	MFSK16
C	PSK31
D	300-baud packet

12. - E3A06

Which of the following is required for microwave propagation via rain scatter?

Select	Answer
A	Rain droplets must be within the E layer
B	The rain must be within radio range of both stations
C	Rain droplets must be electrically charged
D	All of these choices are correct

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 twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
C	At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
D	At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

14. - E3C12

How does the maximum distance of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It increases
B	It peaks at roughly 14 MHz
C	It stays the same
D	It decreases

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	Automatic amplitude and frequency numerical readout
B	Manipulation of time base after trace capture
C	Storage of traces for future reference
D	All of these choices are correct

16. - E4B05

If a frequency counter with a specified accuracy of +/- 10 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	1465.20 Hz
B	146.52 Hz
C	10 Hz
D	146.52 kHz

17. - E4C11

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

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

18. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	A pair of 1 mW input signals will produce a third-order intermodulation product which is 40 dB stronger than the input signal
B	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
C	A pair of 40 dBm signals will theoretically generate a third-order intermodulation product with the same level as the input signals
D	Signals less than 40 dBm will not generate audible third-order intermodulation products

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By observing the AC power line waveform with an oscilloscope
B	By turning off the AC power line main circuit breaker and listening on a battery operated radio
C	By checking the power line voltage with a time domain reflectometer
D	By observing the AC power line voltage with a spectrum analyzer

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The current leads the voltage by 90 degrees
B	The voltage and current are in phase
C	The voltage leads the current by 90 degrees
D	The voltage and current are 180 degrees out of phase

21. - E5B06

What is susceptance?

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

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	The sum of the reactive and resistive components
C	Reactive component
D	Resistive component

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	1.73
C	0.866
D	0.5

24. - E6A17

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

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

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	7
B	5
C	6
D	1

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. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From approximately 10 Hz to no more than 3000 kHz
B	From about 100 kHz to at least 1000 GHz
C	From less than 20 Hz to approximately 300 MHz
D	From a few kHz to no more than 30 MHz

28. - E6E08

How is voltage from a power supply normally furnished to the most common type of monolithic microwave integrated circuit (MMIC)?

Select	Answer
A	Directly to the bias voltage (VCC IN) lead
B	Through a capacitor and RF choke connected to the amplifier input lead
C	MMICs require no operating bias
D	Through a resistor and/or RF choke connected to the amplifier output lead

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The relative fraction of light that is converted to current
B	The effective payback period
C	The open-circuit voltage divided by the short-circuit current under full illumination
D	The output RF power divided by the input DC power

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output only when all inputs are logic "0"
B	It produces logic "0" at its output only when all inputs are logic "1"
C	It produces logic "0" at its output if some but not all inputs are logic "1"
D	It produces logic "1" at its output only when all inputs are logic "1"

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

32. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides D1 with current
B	It increases the current-handling capability of the regulator
C	It provides a constant load for the voltage source
D	It provides negative feedback to improve regulation

34. - E7E04

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

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

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Reducing the effective sample rate by removing samples
C	Attenuating the signal
D	Converting data to binary code decimal form

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	38
B	1
C	76
D	0.03

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. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Differential analysis
B	Numerical analysis
C	Fourier analysis
D	Vector analysis

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the highest audio modulating frequency to the average audio modulating frequency
B	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C	The ratio of the audio modulating frequency to the center carrier frequency
D	The ratio of the carrier center frequency to the audio modulating frequency

40. - E8C01

How is Forward Error Correction implemented?

Select	Answer
A	By transmitting a special algorithm to the receiving station along with the data characters
B	By transmitting extra data that may be used to detect and correct transmission errors
C	By varying the frequency shift of the transmitted signal according to a predefined algorithm
D	By the receiving station repeating each block of three data characters

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	The generation of RF harmonics
C	The generation of key clicks
D	Limits data speed

42. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Radiation resistance plus space impedance
B	Transmission-line resistance plus radiation resistance
C	Radiation resistance plus ohmic resistance
D	Radiation resistance plus transmission resistance

43. - E9B04

What may occur when a directional antenna is operated at different frequencies within the band for which it was designed?

Select	Answer
A	The gain may change depending on frequency
B	Feed point impedance may become negative
C	Element spacing limits could be exceeded
D	The E-field and H-field patterns may reverse

44. - E9C12

Which of the following describes an extended double Zepp antenna?

Select	Answer
A	A portable antenna erected using two push support poles
B	A wideband vertical antenna constructed from precisely tapered aluminum tubing
C	A center fed 1.25 wavelength antenna (two 5/8 wave elements in phase)
D	An end fed folded dipole antenna

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Higher losses
C	Lower Q
D	Greater structural strength

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	Pi-L-network
B	Pi-network
C	A shunt inductor
D	A series capacitor

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

48. - E9G03

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

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

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It modifies the pattern of a DF antenna array to provide a null in one direction
C	It allows DF antennas to receive signals at different vertical angles
D	It provides diversity reception that cancels multipath signals

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

Figure E6-3

Figure E7-3

Figure E7-4