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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	Yes, the DX station initiated the contact
B	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
C	Yes, the displayed frequency is within the 80 meter CW band segment
D	No, one of the sidebands of the CW signal will be out of the band

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 surrounding the National Radio Astronomy Observatory
C	An area in Florida surrounding Cape Canaveral
D	An area in New Mexico surrounding the White Sands Test Area

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for connection to users of the maritime satellite service
B	Communications incidental to the purpose of the amateur service and remarks of a personal nature
C	Business-related messages for non-profit organizations
D	All of these choices are correct

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	The space station must be capable of changing its orbit whenever such a change is ordered by NASA
B	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
C	The space station must cease all transmissions after 5 years
D	All of these choices are correct

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Warn the candidate that continued failure to comply will result in termination of the examination
B	Allow the candidate to complete the examination, but invalidate the results
C	Immediately terminate the candidate's examination
D	Immediately terminate everyone's examination and close the session

6. - E1F10

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

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

7. - E2A12

What is one way to predict the location of a satellite at a given time?

Select	Answer
A	By subtracting the mean anomaly from the orbital inclination
B	By means of the Doppler data for the specified satellite
C	By calculations using the Keplerian elements for the specified satellite
D	By adding the mean anomaly to the orbital inclination

8. - E2B10

Which of the following is an acceptable bandwidth for Digital Radio Mondiale (DRM) based voice or SSTV digital transmissions made on the HF amateur bands?

Select	Answer
A	10 KHz
B	15 KHz
C	20 KHz
D	3 KHz

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of the band, usually 25 kHz above the national calling frequency

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Disconnect
C	Unnumbered Information
D	Acknowledgement

11. - E2E06

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

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

12. - E3A17

What is meant by circularly polarized electromagnetic waves?

Select	Answer
A	Waves with an electric field bent into a circular shape
B	Waves that circle the Earth
C	Waves with a rotating electric field
D	Waves produced by a loop antenna

13. - E3B13

Why is chordal hop propagation desirable?

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

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Westward
B	Northward
C	Southward
D	Eastward

15. - E4A02

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

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

16. - E4B11

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

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

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Fewer components in the receiver
C	Reduced drift
D	Easier for front-end circuitry to eliminate image responses

18. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	Third-order intermodulation produces three products for every input signal within the band of interest
B	Third-order products are an indication of poor image rejection
C	The third-order product of two signals which are in the band of interest is also likely to be within the band
D	The third-order intercept is much higher than other orders

19. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
D	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

20. - E5A14

What is the resonant frequency of a series RLC circuit if R is 22 ohms, L is 50 microhenrys and C is 40 picofarads?

Select	Answer
A	44.72 MHz
B	22.36 MHz
C	3.56 MHz
D	1.78 MHz

21. - E5B06

What is susceptance?

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

22. - E5C07

What is a vector?

Select	Answer
A	The inverse of the tangent function
B	The value of a quantity that changes over time
C	A quantity with both magnitude and an angular component
D	The inverse of the sine function

23. - E5D15

What is the power factor of an R-L circuit having a 45 degree phase angle between the voltage and the current?

Select	Answer
A	0.866
B	0.707
C	0.5
D	1.0

24. - E6A12

Why do many MOSFET devices have internally connected Zener diodes on the gates?

Select	Answer
A	To provide a voltage reference for the correct amount of reverse-bias gate voltage
B	To protect the substrate from excessive voltages
C	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages
D	To keep the gate voltage within specifications and prevent the device from overheating

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Much higher reverse voltage breakdown
B	Enhanced carrier retention time
C	Less forward voltage drop
D	Controlled reverse avalanche voltage

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	3
B	4
C	1
D	2

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	141 turns
B	35 turns
C	13 turns
D	79 turns

28. - E6E09

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

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

29. - E6F10

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

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

30. - E7A11

What type of logic defines "1" as a high voltage?

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

31. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1kHz intervals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	A power supply filter made with interlaced quartz crystals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D15

What is the purpose of a "step-start" circuit in a high voltage power supply?

Select	Answer
A	To compensate for variations of the incoming line voltage
B	To allow for remote control of the power supply
C	To allow the filter capacitors to charge gradually
D	To provide a dual-voltage output for reduced power applications

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

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

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Missing codes and jitter
B	Reference voltage level and sample width in bits
C	Data storage transfer rate
D	Sample clock phase noise

36. - E7G01

What is the typical output impedance of an integrated circuit op-amp?

Select	Answer
A	Very low
B	100 ohms
C	1000 ohms
D	Very high

37. - E7H10

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

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

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 sawtooth wave
C	A sine wave
D	A square wave

39. - E8B11

What is digital time division multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Frequency hopping
B	Phase compandored spread spectrum
C	Direct sequence
D	Binary phase-shift keying

42. - E9A13

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

Select	Answer
A	14.15 dB
B	9.85 dB
C	6.17 dB
D	12.5 dB

43. - E9B07

How does the total amount of radiation emitted by a directional gain antenna compare with the total amount of radiation emitted from an isotropic antenna, assuming each is driven by the same amount of power?

Select	Answer
A	The total amount of radiation from the directional antenna is stronger by its front-to-back ratio
B	The total amount of radiation from the directional antenna is increased by the gain of the antenna
C	They are the same
D	The radiation from the isotropic antenna is 2.15 dB stronger than that from the directional antenna

44. - E9C10

Which of the following describes a Zepp antenna?

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

45. - E9D02

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

Select	Answer
A	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
B	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
C	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
D	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase

46. - E9E06

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

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

47. - E9F12

What impedance does a 1/4 wavelength transmission line present to a generator when the line is open at the far end?

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

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Prime axis
B	Reactance axis
C	Impedance axis
D	Polar axis

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It must be mounted more than 1 wavelength above ground
B	Its overall length must not exceed 1/4 wavelength
C	It should be configured as a four-sided loop
D	It should be one or more wavelengths long

50. - E0A01

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

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

Figure E6-5

Figure E9-3