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

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1. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Ensure signals from your station are less than the uncontrolled Maximum Permitted Exposure (MPE) limits
B	Ensure signals from your station are less than the controlled Maximum Permitted Exposure (MPE) limits
C	Ensure signals from your station are less than the uncontrolled Maximum Permitted Emission (MPE) limits
D	Ensure signals from your station are less than the controlled Maximum Permitted Emission (MPE) limits

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	14.100 MHz
B	14.070 MHz
C	14.349 MHz
D	14.149 MHz

3. - 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

4. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	The entire band
B	Only the top 3 kHz
C	None
D	Only the bottom 3 kHz

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	Two-way transmissions of data
B	Two-way transmissions in excess of 1000 feet
C	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
D	One-way transmission of measurements at a distance from the measuring instrument

6. - E1E12

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

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

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	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
B	All privileges of the Amateur Extra Class license
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. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	FM and CW
B	PSK and packet
C	SSB and SSTV
D	All these choices are correct

9. - E2B02

How many horizontal lines make up a fast-scan (NTSC) television frame?

Select	Answer
A	60
B	1080
C	525
D	30

10. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	All these choices are correct
B	To separate the calling stations from the DX station
C	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations
D	To improve operating efficiency by reducing interference

11. - E2D09

What type of modulation is used for JT65 contacts?

Select	Answer
A	PSK
B	IEEE 802.11
C	Multi-tone AFSK
D	RTTY

12. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK applies the data signal to the transmitter VFO, while AFSK transmits tones via phone
B	Direct FSK occupies less bandwidth
C	Direct FSK can transmit faster baud rates
D	Only direct FSK can be decoded by computer

13. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?

Select	Answer
A	500 miles, if the moon is at perigee
B	2000 miles, if the moon is at apogee
C	5000 miles, if the moon is at perigee
D	12,000 miles, if the moon is visible by both stations

14. - E3B11

At what time of day can sporadic E propagation occur?

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

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar emission at 304 GHz, correlated to x-ray flare levels
B	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity
C	The ratio of x-ray flux to radio flux, correlated to sunspot number
D	UV emissions at 304 angstroms, correlated to the solar flux index

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Keep the signal ground connection of the probe as short as possible
B	Never use a high-impedance probe to measure a low-impedance circuit
C	All these choices are correct
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B08

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

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

18. - E4C01

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

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

19. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal that will cause 1 dB of gain compression
B	The difference in dB between the noise floor and the third-order intercept point
C	The minimum difference in dB between the levels of two FM signals that will cause one signal to block the other
D	The minimum difference in dB between two signals which produce third-order intermodulation products greater than the noise floor

20. - E4E11

What could cause local AM broadcast band signals to combine to generate spurious signals in the MF or HF bands?

Select	Answer
A	Your station receiver IF amplifier stage is defective
B	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
C	One or more of the broadcast stations is transmitting an over-modulated signal
D	You are receiving skywave signals from a distant station

21. - E5A16

What is the resonant frequency of an RLC circuit if R is 33 ohms, L is 50 microhenries and C is 10 picofarads?

Select	Answer
A	7.12 kHz
B	23.5 kHz
C	7.12 MHz
D	23.5 MHz

22. - E5B06

What is susceptance?

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

24. - E5D15

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

Select	Answer
A	0.866
B	0.5
C	0.707
D	1.0

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	An FET that has no current flow between source and drain when no gate voltage is applied
B	Any FET without a channel
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	Any FET for which holes are the majority carriers

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Thermionic emission diode
B	Electrolytic rectifier
C	PIN junction
D	Metal-semiconductor junction

27. - E6C08

In Figure E6-3, what is the schematic symbol for a NAND gate?

Select	Answer
A	1
B	4
C	3
D	2

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 have lower Q characteristics
B	Toroidal cores exhibit greater hysteresis
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. - E6E08

How is power supplied to the most common type of MMIC?

Select	Answer
A	MMICs require no operating bias
B	Through a resistor and/or RF choke connected to the amplifier output lead
C	Through a capacitor and RF choke connected to the amplifier input lead
D	Directly to the bias voltage (VCC IN) lead

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A lens and a photomultiplier
B	An amplitude modulated helium-neon laser
C	A frequency modulated helium-neon laser
D	An LED and a phototransistor

31. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic 1 at its output only when all inputs are logic 1
B	It produces logic 0 at its output only when all inputs are logic 0
C	It produces logic 0 at its output if some but not all inputs are logic 1
D	It produces logic 0 at its output only when all inputs are logic 1

32. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they invert the sidebands causing distortion
B	Because they maintain the sidebands, thus causing multiple duplicate signals
C	Because they are relatively far in frequency from the desired signal
D	Because they are relatively close in frequency to the desired signal

33. - E7C12

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	The Q of Pi-networks can be controlled
B	Pi-networks are more stable
C	Pi-networks provide balanced input and output
D	L-networks cannot perform impedance transformation

34. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-2?

Select	Answer
A	It provides a constant load for the voltage source
B	It provides D1 with current
C	It controls the current supplied to the load
D	It provides negative feedback to improve regulation

35. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a balanced modulator followed by a filter
B	By using a loop modulator followed by a mixer
C	By using a reactance modulator followed by a mixer
D	By driving a product detector with a DSB signal

36. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	8 bits
B	10 bits
C	6 bits
D	4 bits

37. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It increases linearly with increasing frequency
B	It does not vary with frequency
C	It decreases logarithmically with increasing frequency
D	It decreases linearly with increasing frequency

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
B	An electronic circuit also known as a monostable multivibrator
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic circuit consisting of a precision push-pull amplifier with a differential input

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The frequency of the modulating signal
B	Amplifier gain
C	Speech characteristics
D	The degree of carrier suppression

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	0.214
B	2.14
C	0.47
D	47

41. - E8C11

What is the relationship between symbol rate and baud?

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

42. - E8D10

What are some of the differences between the Baudot digital code and ASCII?

Select	Answer
A	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
B	Baudot uses 4 data bits per character, ASCII uses 7 or 8; Baudot uses 1 character as a letters/figures shift code, ASCII has no letters/figures code
C	Baudot uses 6 data bits per character, ASCII uses 7 or 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes
D	Baudot uses 5 data bits per character, ASCII uses 7 or 8; Baudot uses 2 characters as letters/figures shift codes, ASCII has no letters/figures shift code

43. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Soil conductivity
B	The standing wave ratio
C	Take-off angle
D	Distance from the transmitter

44. - E9B09

What type of computer program technique is commonly used for modeling antennas?

Select	Answer
A	Graphical analysis
B	Mutual impedance analysis
C	Method of Moments
D	Calculus differentiation with respect to physical properties

45. - E9C04

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

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

46. - E9D02

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

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

47. - E9E05

How must an antenna's driven element be tuned to use a hairpin matching system?

Select	Answer
A	The driven element reactance must be inductive
B	The driven element radiation resistance must be higher than the characteristic impedance of the transmission line
C	The driven element resonance must be lower than the operating frequency
D	The driven element reactance must be capacitive

48. - E9F13

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

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

49. - E9G07

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

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

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Atmospheric noise is so high that gain over a dipole is not important
B	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	All these choices are correct
D	Low loss coax transmission line is essential for good performance

Figure E6-3

Figure E7-2

Figure E9-3