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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
B	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
C	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

2. - E1B10

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

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

3. - E1C12

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

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

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the ITU
B	Any amateur station designated by NASA
C	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
D	All of these choices are correct

5. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Issue the examinee the new or upgrade license
B	Photocopy all examination documents and forward them to the FCC for processing
C	All these choices are correct
D	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	It was imported from a manufacturer in another country and was certificated by that country's government
B	The equipment dealer assembled it from a kit
C	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
D	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

7. - E2A08

Why should effective radiated power to a satellite which uses a linear transponder be limited?

Select	Answer
A	To avoid reducing the downlink power to all other users
B	To prevent the satellite from emitting out-of-band signals
C	To avoid interfering with terrestrial QSOs
D	To prevent creating errors in the satellite telemetry

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	15 KHz
B	10 KHz
C	20 KHz
D	3 KHz

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 m
B	33 cm
C	30 m
D	6 m

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. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	FSK
C	Spread spectrum
D	Pulse modulation

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Urban areas
B	Forests
C	Mountain ranges
D	Bodies of water

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	Their polarization is randomly modified
B	They become elliptically polarized
C	They are bent toward the magnetic poles
D	They become phase-locked

14. - E3C01

What does the term ray tracing describe in regard to radio communications?

Select	Answer
A	Determining the radiation pattern from an array of antennas
B	The process in which an electronic display presents a pattern
C	Modeling a radio wave's path through the ionosphere
D	Evaluating high voltage sources for X-Rays

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	Calibration of the vertical scale is no longer valid
B	All signals will have a DC offset
C	False signals are displayed
D	False triggering occurs

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Intermodulation distortion occurs
B	Harmonics are generated
C	A less accurate reading results
D	Cross modulation occurs

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	Easier for front-end circuitry to eliminate image responses
C	Reduced drift
D	Fewer components in the receiver

18. - E4D04

Which of the following may reduce or eliminate intermodulation interference in a repeater caused by another transmitter operating in close proximity?

Select	Answer
A	A properly terminated circulator at the output of the transmitter
B	A band-pass filter in the feed line between the transmitter and receiver
C	A Class C final amplifier
D	A Class D final amplifier

19. - E4E08

What type of signal is picked up by electrical wiring near a radio antenna?

Select	Answer
A	A differential-mode signal at the AC power line frequency
B	A common-mode signal at the frequency of the radio transmitter
C	Harmonics of the AC power line frequency
D	An electrical-sparking signal

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. - 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	68.2 degrees with the voltage leading the current
B	68.2 degrees with the voltage lagging the current
C	14.0 degrees with the voltage leading the current
D	14.0 degrees with the voltage lagging the current

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 8
D	Point 7

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

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 keep the gate voltage within specifications and prevent the device from overheating
D	To reduce the chance of the gate insulation being punctured by static discharges or excessive voltages

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	An internal capacitance that varies with the applied voltage
D	A constant current drop under conditions of varying voltage

26. - E6C03

What is tri-state logic?

Select	Answer
A	Low power logic devices designed to operate at 3 volts
B	Logic devices that utilize ternary math
C	Logic devices with 0, 1, and high impedance output states
D	Proprietary logic devices manufactured by Tri-State Devices

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

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Ground-plane construction
B	Point-to-point construction
C	Wave-soldering construction
D	Microstrip construction

29. - E6F01

What is photoconductivity?

Select	Answer
A	The decreased conductivity of an illuminated semiconductor
B	The conversion of photon energy to electromotive energy
C	The conversion of electromotive energy to photon energy
D	The increased conductivity of an illuminated semiconductor

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces one output pulse for every ten input pulses
B	It adds two decimal numbers together
C	It decodes a decimal number for display on a seven segment LED display
D	It produces ten output pulses for every input pulse

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low bandwidth
B	High power gain
C	Low input impedance
D	High filament voltage

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 relative frequencies of the individual crystals
B	The DC voltage applied to the quartz crystal
C	The amplitude of the signals passing through the filter
D	The gain of the RF stage preceding the filter

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The resistance of a control element is varied in direct proportion to the line voltage or load current
B	It is generally less efficient than a linear regulator
C	The controlled device's duty cycle is changed to produce a constant average output voltage
D	It gives a ramp voltage at its output

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce AM signals
B	By varying the tuning of an amplifier tank circuit to produce AM signals
C	By varying the tuning of a microphone preamplifier to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce PM signals

35. - E7F13

What is the function of taps in a digital signal processing filter?

Select	Answer
A	To reduce excess signal pressure levels
B	Provide incremental signal delays for filter algorithms
C	Select the point at which baseband signals are generated
D	Provide access for debugging software

36. - E7G06

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

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

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Taft, Pierce and negative feedback
B	Colpitts, Hartley and Pierce
C	Taft, Hartley and Pierce
D	Pierce, Fenner and Beane

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals can be regenerated multiple times without error
B	Digital signals always occupy a narrower bandwidth
C	All of these choices are correct
D	Less complex circuitry is required for digital signal generation and detection

39. - E8B01

What is the term for the ratio between the frequency deviation of an RF carrier wave and the modulating frequency of its corresponding FM-phone signal?

Select	Answer
A	Quieting index
B	FM compressibility
C	Modulation index
D	Percentage of modulation

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	All of these choices are correct
B	It improves carrier suppression
C	It is easier to demodulate with a conventional, non-synchronous detector
D	This results in the least possible transmitted bandwidth for the particular mode

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Excessive numbers of retries
B	Excessive transmit audio levels
C	Bit errors in the modem
D	Ground loops

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(total resistance / radiation resistance) x 100 per cent
B	(radiation resistance / total resistance) x 100 per cent
C	(effective radiated power / transmitter output) x 100 percent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	Polar plots of the far field elevation and azimuth patterns
B	SWR vs frequency charts
C	Antenna gain
D	All of these choices are correct

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The lobes align more in the direction of the wire
B	The front-to-back ratio decreases
C	The lobes become more perpendicular to the wire
D	The vertical angle increases

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To minimize the Q
B	To minimize losses
C	To maximize losses
D	To swamp out harmonics

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	A shunt inductor
C	A series capacitor
D	Pi-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	The same as the input impedance to the generator
B	The same as the characteristic impedance of the line
C	Very high impedance
D	Very low impedance

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage lines and current chords
B	Resistance circles and reactance arcs
C	Resistance lines and reactance chords
D	Voltage circles and current arcs

49. - E9H10

How can the output voltage of a multiple turn receiving loop antenna be increased?

Select	Answer
A	By reducing the permeability of the loop shield
B	By winding adjacent turns in opposing directions
C	By increasing either the number of wire turns in the loop or the area of the loop structure or both
D	By increasing the number of wire turns in the loop and reducing the area of the loop structure

50. - E0A09

Which insulating material commonly used as a thermal conductor for some types of electronic devices is extremely toxic if broken or crushed and the particles are accidentally inhaled?

Select	Answer
A	Mica
B	Uranium Hexafluoride
C	Zinc oxide
D	Beryllium Oxide

Figure E5-2