US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A08

What does SAR measure?

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

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	100 watts PEP effective radiated power relative to an isotropic radiator
B	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
C	50 watts PEP effective radiated power relative to a dipole
D	50 watts PEP effective radiated power relative to an isotropic radiator

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A proposal must be submitted to the National Park Service
B	A form FSD-15 must be submitted to the Department of the Interior
C	A letter of intent must be filed with the Environmental Protection Agency
D	An Environmental Assessment must be submitted to the FCC

4. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	All these choices are correct
B	IARP agreement
C	CEPT agreement
D	ITU reciprocal license

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	All these choices are correct
B	The station's six-character Maidenhead grid locator
C	Call sign
D	The output power of the balloon transmitter

6. - E1E02

Who does Part 97 task with maintaining the pools of questions for all U.S. amateur license examinations?

Select	Answer
A	The VEs
B	The FCC
C	The VECs
D	The ARRL

7. - E1F08

Which of the following types of amateur station communications are prohibited?

Select	Answer
A	Communications that have religious content
B	Communications in a language other than English
C	Communications that have political content, except as allowed by the Fairness Doctrine
D	Communications transmitted for hire or material compensation, except as otherwise provided in the rules

8. - E2A06

What are Keplerian elements?

Select	Answer
A	High-emission heater filaments used in magnetron tubes
B	Encrypting codes used for spread spectrum modulation
C	Phase reversing elements in a Yagi antenna
D	Parameters that define the orbit of a satellite

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To provide vertical synchronization
B	To lock the color burst oscillator in color SSTV images
C	To identify the SSTV mode being used
D	To identify the call sign of the station transmitting

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The rules of order for meetings between contest sponsors
B	The most common set of contest rules
C	A standard for submission of electronic contest logs
D	A method of exchanging information during a contest QSO

11. - E2D01

Which of the following digital modes is designed for meteor scatter communications?

Select	Answer
A	APRS
B	WSPR
C	MSK144
D	Hellschreiber

12. - E2E13

Which of these digital modes has the fastest data throughput under clear communication conditions?

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

13. - E3A06

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

14. - E3B11

At what time of day can sporadic E propagation occur?

Select	Answer
A	Any time
B	Only in hours of darkness
C	Only around sunset
D	Only around sunset and sunrise

15. - E3C13

What type of polarization is best for ground-wave propagation?

Select	Answer
A	Elliptical
B	Vertical
C	Circular
D	Horizontal

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	Calibration of the vertical scale is no longer valid
B	A false, jittery low-frequency version of the signal is displayed
C	All signals will have a DC offset
D	Excessive blanking occurs, which prevents display of the signal

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The inductance to capacitance ratio
B	The resonant frequency of the circuit
C	The frequency shift
D	The bandwidth of the circuit's frequency response

18. - E4C01

What is an effect of excessive phase noise in a receiver's local oscillator?

Select	Answer
A	It decreases receiver third-order intercept point
B	It can combine with strong signals on nearby frequencies to generate interference
C	It can affect the receiver's frequency calibration
D	It limits the receiver's ability to receive strong signals

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To increase rejection of signals outside the desired band
B	To store often-used frequencies
C	To provide a range of AGC time constants
D	To allow selection of the optimum RF amplifier device

20. - E4E10

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	A malfunctioning illuminated advertising display
C	All these choices are correct
D	A defective doorbell or doorbell transformer inside a nearby residence

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower reactance
B	Lower self-resonant frequency
C	Higher self-resonant frequency
D	Lower losses

22. - E5B08

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 100 ohms, R is 100 ohms, and XL is 75 ohms?

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

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On a horizontal line, offset vertically above the horizontal axis
B	On a line through the origin, slanted at 45 degrees
C	On the vertical axis
D	On the horizontal axis

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	To increase compensating capacitance
C	To increase neutralizing resistance
D	To reduce phase shift along the connection

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	6
B	2
C	3
D	1

26. - E6B10

In Figure E6-2, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	1
B	6
C	7
D	5

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A type of transistor whose gain can be changed by digital logic circuits
B	A logic circuit that can be modified during use
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	Programmable equipment used for testing digital logic integrated circuits

28. - E6D10

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

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

29. - 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

30. - E6F09

What is the efficiency of a photovoltaic cell?

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

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	1
B	2
C	4
D	8

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Push-push
B	Push-pull
C	Class AB
D	Class C

33. - E7C03

What advantage does a series-L Pi-L-network have over a series-L Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater harmonic suppression
B	Higher efficiency
C	Does not require a capacitor
D	Greater transformation range

34. - E7D03

What device is typically used as a stable voltage reference in a linear voltage regulator?

Select	Answer
A	A Zener diode
B	An SCR
C	A tunnel diode
D	A varactor diode

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce AM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable resistance
C	To produce PM or FM signals by using an electrically variable inductance or capacitance
D	To produce PM signals by using an electrically variable resistance

36. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample width in bits
B	Sample rate
C	Sample clock phase noise
D	Processor latency

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	0.21
B	24
C	47
D	94

38. - E7H13

Which of the following is a technique for providing highly accurate and stable oscillators needed for microwave transmission and reception?

Select	Answer
A	Use a GPS signal reference
B	All these choices are correct
C	Use a rubidium stabilized reference oscillator
D	Use a temperature-controlled high Q dielectric resonator

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A D'Arsonval meter
B	An absorption wave meter
C	A grid dip meter
D	A true-RMS calculating meter

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

41. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	Baud is twice the symbol rate
B	Baud is only used for RTTY
C	Symbol rate is only used for packet-based modes
D	They are the same

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

Select	Answer
A	Repeat Request Rate (RRR)
B	Baud rate
C	Intermodulation Distortion (IMD)
D	Signal-to-noise ratio

43. - E9A05

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

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

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	75 degrees
B	50 degrees
C	25 degrees
D	30 degrees

45. - E9C06

What is the effect of adding a terminating resistor to a rhombic antenna?

Select	Answer
A	It changes the radiation pattern from bidirectional to unidirectional
B	It reflects the standing waves on the antenna elements back to the transmitter
C	It changes the radiation pattern from horizontal to vertical polarization
D	It decreases the ground loss

46. - E9D11

Which of the following conductors would be best for minimizing losses in a station's RF ground system?

Select	Answer
A	Solid wire
B	Stranded wire
C	Resistive wire, such as spark plug wire
D	Wide flat copper strap

47. - E9E09

Which of the following is used to shunt-feed a grounded tower at its base?

Select	Answer
A	Hairpin match
B	Double-bazooka match
C	Gamma match
D	All these choices are correct

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	8.5 meters
C	10.6 meters
D	13.3 meters

49. - E9G02

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

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

50. - E9H11

What feature of a cardioid pattern antenna makes it useful for direction finding?

Select	Answer
A	High radiation angle
B	Broadband response
C	A very sharp single null
D	A very sharp peak

Figure E6-1

Figure E6-2

Figure E9-1