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

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1. - 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	Beryllium Oxide
B	Mica
C	Zinc oxide
D	Uranium Hexafluoride

2. - E1A03

What is the maximum legal carrier frequency on the 20 meter band for transmitting USB AFSK digital signals having a 1 kHz bandwidth?

Select	Answer
A	14.070 MHz
B	14.100 MHz
C	14.349 MHz
D	14.149 MHz

3. - E1B12

What must the control operator of a repeater operating in the 70 cm band do if a radiolocation system experiences interference from that repeater?

Select	Answer
A	All these choices are correct
B	Cease operation or make changes to the repeater to mitigate the interference
C	File an FAA NOTAM (Notice to Airmen) with the repeater system's ERP, call sign, and six-character grid locator
D	Reduce the repeater antenna HAAT (Height Above Average Terrain)

4. - E1C14

How long must an operator wait after filing a notification with the Utilities Technology Council (UTC) before operating on the 2200 meter or 630 meter band?

Select	Answer
A	Operators may not operate until a test signal has been transmitted in coordination with the local power company
B	Operators may operate after 30 days, providing they have not been told that their station is within 1 km of PLC systems using those frequencies
C	Operators must not operate until approval is received
D	Operations may commence immediately, and may continue unless interference is reported by the UTC

5. - E1D06

What is the maximum permitted transmitter output power when operating a model craft by telecommand?

Select	Answer
A	1 watt
B	5 watts
C	2 watts
D	100 watts

6. - E1E12

What must the VE team do with the application form if the examinee does not pass the exam?

Select	Answer
A	Return the application document to the examinee
B	Send the application form to the FCC and inform the FCC of the grade
C	Destroy the application form
D	Maintain the application form with the VEC's records

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

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From west to east
B	From east to west
C	From south to north
D	From north to south

9. - E2B09

What hardware, other than a receiver with SSB capability and a suitable computer, is needed to decode SSTV using Digital Radio Mondiale (DRM)?

Select	Answer
A	No other hardware is needed
B	A special front end limiter
C	A special notch filter to remove synchronization pulses
D	A special IF converter

10. - E2C07

What is the Cabrillo format?

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

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Time and frequency
B	Radio direction finding spectrum analysis
C	Latitude and longitude
D	Polar coordinates

12. - E2E06

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

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

13. - E3A12

What is the cause of auroral activity?

Select	Answer
A	Meteor showers concentrated in the extreme northern and southern latitudes
B	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
C	An extreme low-pressure area in the polar regions
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Morning
B	Noon
C	Afternoon or early evening
D	Late at night

15. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	Four times as great
B	10 percent greater
C	50 percent greater
D	Twice as great

16. - E4A07

Which of the following is an advantage of using an antenna analyzer compared to an SWR bridge to measure antenna SWR?

Select	Answer
A	Antenna analyzers automatically tune your antenna for resonance
B	Antenna analyzers display a time-varying representation of the modulation envelope
C	All these choices are correct
D	Antenna analyzers do not need an external RF source

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

Select	Answer
A	Modulate the transmitter using two AF signals having harmonically related frequencies and observe the RF output with a peak reading wattmeter
B	Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
C	Modulate the transmitter using two RF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer
D	Modulate the transmitter using two RF signals having harmonically related frequencies and observe the RF output with a logic analyzer

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	Anti-aliasing input filter bandwidth
B	CPU register width in bits
C	Analog-to-digital converter sample width in bits
D	RAM speed used for data storage

19. - E4D05

What transmitter frequencies would cause an intermodulation-product signal in a receiver tuned to 146.70 MHz when a nearby station transmits on 146.52 MHz?

Select	Answer
A	146.88 MHz and 146.34 MHz
B	173.35 MHz and 139.40 MHz
C	146.10 MHz and 147.30 MHz
D	146.34 MHz and 146.61 MHz

20. - E4E01

What problem can occur when using an automatic notch filter (ANF) to remove interfering carriers while receiving CW signals?

Select	Answer
A	Removal of the CW signal as well as the interfering carrier
B	Received CW signals will appear to be modulated at the DSP clock frequency
C	Ringing in the DSP filter will completely remove the spaces between the CW characters
D	Any nearby signal passing through the DSP system will overwhelm the desired signal

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of the inductance multiplied by the reactance of the capacitance
B	Reactance of either the inductance or capacitance multiplied by the resistance
C	Reactance of either the inductance or capacitance divided by the resistance
D	Resistance divided by the reactance of either the inductance or capacitance

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	One time constant
B	One exponential period
C	A time factor of one
D	An exponential rate of one

23. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Elliptical coordinates
B	Polar coordinates
C	Maidenhead grid
D	Faraday grid

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	600 watts
B	200 watts
C	1600 watts
D	1000 watts

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In high-current rectifier circuits
B	In very low-frequency RF circuits
C	In microwave circuits
D	In high-power audio circuits

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Tunnel diode
B	Varactor diode
C	Zener diode
D	Silicon-controlled rectifier

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
C	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
D	A resistor that ensures that an oscillator frequency does not drift

28. - E6D05

What is one reason for using ferrite cores rather than powdered iron in an inductor?

Select	Answer
A	Ferrite toroids generally have better temperature stability
B	Ferrite toroids generally require fewer turns to produce a given inductance value
C	Ferrite toroids are easier to use with surface mount technology
D	Ferrite toroids generally have lower initial permeability

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Gallium nitride
B	Silicon
C	Silicon dioxide
D	Silicon nitride

30. - E6F01

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Protons
B	Photons
C	Holes
D	Electrons

31. - E7A04

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

Select	Answer
A	4
B	8
C	2
D	1

32. - E7B06

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

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

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	A filter using lattice-shaped quartz crystals for high-Q performance
B	A filter with narrow bandwidth and steep skirts made using quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
D	A power supply filter made with interlaced quartz crystals

34. - E7D11

What is the function of the pass transistor in a linear voltage regulator circuit?

Select	Answer
A	Provides a stable input impedance over a wide range of source voltage
B	Maintains nearly constant output impedance over a wide range of load current
C	Permits a wide range of output voltage settings
D	Maintains nearly constant output voltage over a wide range of load current

35. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To remove third-order distortion products
B	To reduce impulse noise reception
C	For compatibility with transmitters using phase modulation
D	For higher efficiency

36. - E7F08

What is the function of decimation?

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

37. - E7G01

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

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

38. - E7H09

What type of frequency synthesizer circuit uses a phase accumulator, lookup table, digital to analog converter, and a low-pass anti-alias filter?

Select	Answer
A	A phase-locked loop synthesizer
B	A diode-switching matrix synthesizer
C	A hybrid synthesizer
D	A direct digital synthesizer

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

40. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.47
B	47
C	0.214
D	2.14

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Use of sinusoidal data pulses
B	Use of trapezoidal data pulses
C	Zero-sum character encoding
D	Reed-Solomon character encoding

42. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	632 watts
B	159 watts
C	252 watts
D	63.2 watts

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region where the shape of the antenna pattern is independent of distance
B	The region where radiated power dissipates over a specified time period
C	The region where radiated field strengths are constant
D	The region of the ionosphere where radiated power is not refracted

45. - E9C03

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed in phase?

Select	Answer
A	Omni-directional
B	A Figure-8 end-fire along the axis of the array
C	A Figure-8 broadside to the axis of the array
D	Cardioid

46. - E9D11

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

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

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It creates a low-angle radiation pattern
B	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
C	It allows single-band antennas to operate on other bands
D	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter

48. - E9F10

What impedance does a 1/8-wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	An inductive reactance
B	The same as the characteristic impedance of the line
C	A capacitive reactance
D	Zero

49. - 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 reactance axis
D	The voltage axis

50. - E9H07

Why is RF attenuation used when direction-finding?

Select	Answer
A	To increase receiver sensitivity
B	To compensate for isotropic directivity and the antenna effect of feed lines
C	To narrow the receiver bandwidth
D	To prevent receiver overload which reduces pattern nulls

Figure E9-3