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	60 meter band
B	12 meter band
C	30 meter band
D	17 meter band

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific segments in the amateur service MF, HF, VHF and UHF bands
B	Military Auxiliary Radio System (MARS) channels
C	All amateur service frequencies authorized to the control operator
D	Specific local government channels

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When agreed upon by the sending or receiving station
B	Never
C	Only when transmitting RTTY or data emissions
D	When approved by the National Telecommunication and Information Administration

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station located more than 50 km above the Earth's surface
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 on the Earth's surface for communication with other Earth stations by means of Earth satellites

5. - E1E02

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

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

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands
B	All privileges of the Extra Class license
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
D	None, they must obtain a U.S. license

7. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because the satellite is spinning
B	Because of the Doppler Effect
C	Because of the satellite's low orbital altitude
D	Because of ionospheric absorption

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	A separate VHF or UHF audio link
B	Frequency modulation of the video carrier
C	Frequency-modulated sub-carrier
D	All of these choices are correct

9. - E2C04

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

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

10. - E2D06

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

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

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO
B	Audio FSK has a superior frequency response
C	Audio FSK can be performed anywhere in the transmit chain
D	Direct FSK uses a DC-coupled data connection

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Likelihood of rain-scatter along cold or warm fronts
C	Locations of auroral reflecting zones
D	Sporadic E propagation

13. - E3B13

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss along the path compared to normal skip propagation
B	Atmospheric noise is lower in the direction of chordal hop propagation
C	The MUF for chordal hop propagation is much lower than for normal skip propagation
D	Signals travel faster along ionospheric chords

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. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Network analyzer
B	Bit error rate tester
C	Logic analyzer
D	Modulation monitor

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the analyzer near the antenna base
C	Loosely couple the antenna and a dummy load to the analyzer
D	Connect the analyzer via a high-impedance transformer to the antenna

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	One-half the maximum sample rate
B	The reference voltage of the analog-to-digital converter
C	The maximum count value of the analog-to-digital converter
D	One-half the maximum sampling buffer size

18. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Lack of neutralization
B	Nonlinear circuits or devices
C	Too little gain
D	Positive feedback

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	Arcing contacts in a thermostatically controlled device
B	All of these choices are correct
C	A defective doorbell or doorbell transformer inside a nearby residence
D	A malfunctioning illuminated advertising display

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Approximately equal to circuit resistance
B	Approximately equal to capacitive reactance
C	Low, as compared to the circuit resistance
D	Approximately equal to inductive reactance

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

22. - E5C01

Which of the following represents a capacitive reactance in rectangular notation?

Select	Answer
A	X
B	+jX
C	Omega
D	-jX

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In a direction opposite to the current
B	In a direction determined by the left-hand rule
C	In all directions; omni-directional
D	In the same direction as the current

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	2
B	5
C	6
D	4

25. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A negative resistance region
B	A constant voltage drop under conditions of varying current
C	A constant current drop under conditions of varying voltage
D	An internal capacitance that varies with the applied voltage

26. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	The input switching threshold is about one-half the power supply voltage
B	The input switching threshold is about two times the power supply voltage
C	Larger bypass capacitors are used in CMOS circuit design
D	Input signals are stronger

27. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores have lower Q characteristics
C	Toroidal cores exhibit greater hysteresis
D	Toroidal cores confine most of the magnetic field within the core material

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	TO-220
B	Radial lead
C	Axial lead
D	Surface mount

29. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Silicon
B	Cadmium Sulfide
C	Copper oxide
D	Selenium

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	J-K flip-flop
B	Monostable multivibrator
C	Astable multivibrator
D	T flip-flop

31. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Use a phase inverter in the output filter
C	Tune both the input and output for maximum power
D	Install parasitic suppressors and/or neutralize the stage

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 amplitude of the signals passing through the filter
C	The relative frequencies of the individual crystals
D	The gain of the RF stage preceding the filter

33. - E7D08

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

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

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	Spurious mixer products are generated
B	Automatic limiting occurs
C	A beat frequency is generated
D	Mixer blanking occurs

35. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	A notch filter
C	An adaptive filter
D	An elliptical filter

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As an audio filter in a receiver
B	As a low-pass filter used between a transmitter and a transmission line
C	For smoothing power supply output
D	As a high-pass filter used to block RFI at the input to receivers

37. - E7H10

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

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

38. - E8A02

What type of wave has a rise time significantly faster than its fall time (or vice versa)?

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

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B	Two or more signals are quadrature modulated to increase bandwidth efficiency
C	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
D	Two or more signals are arranged to share discrete time slots of a data transmission

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	If errors are detected, a retransmission is requested
B	Special binary codes provide automatic correction
C	If errors are detected, redundant data is substituted
D	Special polynomial codes provide automatic correction

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Harmonics on higher bands
B	Strong ALC action
C	High reflected power
D	Rapid signal fading

42. - E9A05

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

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

43. - E9B16

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

Select	Answer
A	1
B	4
C	3
D	7

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

45. - E9D02

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

Select	Answer
A	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
B	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
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. - E9E13

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed low-impedance loads from a high-impedance source
B	It is used to feed high-impedance antennas from a low-impedance source
C	It is used to divide power equally between two 50 ohm loads while maintaining 50 ohm input impedance
D	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band

47. - E9F14

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

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

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The current axis
B	The resistance axis
C	The voltage axis
D	The reactance axis

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A08

What does SAR measure?

Select	Answer
A	Signal Amplification Rating
B	The rate at which RF energy is absorbed by the body
C	Synthetic Aperture Ratio of the human body
D	The rate of RF energy reflected from stationary terrain

Figure E6-2

Figure E7-3

Figure E9-2

Figure E9-3