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

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1. - E0A03

Over what range of frequencies are the FCC human body RF exposure limits most restrictive?

Select	Answer
A	3 to 30 MHz
B	300 kHz to 3 MHz
C	30 to 300 MHz
D	300 to 3000 MHz

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any amateur license with an FCC Marine or Aircraft endorsement
B	Any FCC-issued amateur license
C	Only General Class or higher amateur licenses
D	An unrestricted Radiotelephone Operator Permit

3. - E1B07

To what type of regulations does PRB-1 apply?

Select	Answer
A	State and local zoning
B	FAA tower height limits
C	Homeowners associations
D	Use of wireless devices in vehicles

4. - E1C09

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	0.5
C	3.0
D	2.0

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	Two-way transmissions in excess of 1000 feet
B	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
C	Two-way transmissions of data
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	Send the application form to the FCC and inform the FCC of the grade
B	Destroy the application form
C	Maintain the application form with the VEC's records
D	Return the application document to the examinee

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

8. - E2A02

Which of the following occurs when a satellite is using an inverting linear transponder?

Select	Answer
A	Signal position in the band is reversed
B	Upper sideband on the uplink becomes lower sideband on the downlink, and vice versa
C	All these choices are correct
D	Doppler shift is reduced because the uplink and downlink shifts are in opposite directions

9. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	30
B	90
C	120
D	60

10. - E2C12

What technique do individual nodes use to form a mesh network?

Select	Answer
A	Acting as store-and-forward digipeaters
B	Forward error correction and Viterbi codes
C	Custom code plugs for the local trunking systems
D	Discovery and link establishment protocols

11. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	802.11
B	AX.25
C	AMTOR
D	PACTOR

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE radios send a constant tone code to establish a frequency for future use
B	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
C	ALE radios monitor an internet site for the frequency they are being paged on
D	ALE radios activate when they hear their signal echoed by back scatter

13. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the moon is full
B	When the MUF is above 30 MHz
C	When the moon is at perigee
D	When the moon is at apogee

14. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between a point on the equator and its antipodal point
B	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
C	Propagation between points located on the magnetic equator
D	Propagation between points at the same latitude

15. - E3C02

What is indicated by a rising A or K index?

Select	Answer
A	Decreasing disruption of the geomagnetic field
B	Increasing disruption of the geomagnetic field
C	An increase in the critical frequency
D	Higher levels of solar UV radiation

16. - E4A02

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

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

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S21
B	S11
C	S12
D	S22

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
B	Two digital signals combining from alternate time slots
C	Local oscillator phase noise mixing with adjacent strong signals to create interference to desired signals
D	Two out-of-band signals mixing to generate an in-band spurious signal

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Positive feedback
B	Lack of neutralization
C	Nonlinear circuits or devices
D	Too little gain

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Reactive current only
B	Differential-mode current
C	Return current
D	Common-mode current

21. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The voltage and current are 180 degrees out of phase
B	The current leads the voltage by 90 degrees
C	The voltage leads the current by 90 degrees
D	The voltage and current are in phase

22. - 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	14.0 degrees with the voltage leading the current
B	68.2 degrees with the voltage lagging the current
C	68.2 degrees with the voltage leading the current
D	14.0 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 the horizontal axis
B	On a horizontal line, offset vertically above the horizontal axis
C	On a line through the origin, slanted at 45 degrees
D	On the vertical axis

24. - E5D01

What is the result of skin effect?

Select	Answer
A	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
B	Thermal effects on the surface of the conductor increase the impedance
C	Thermal effects on the surface of the conductor decrease the impedance
D	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
C	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
D	Base-to-emitter resistance of approximately 6 to 7 ohms

26. - 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	Longer carrier retention time
C	More constant reverse avalanche voltage
D	Less forward voltage drop

27. - E6C03

What is tri-state logic?

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

28. - E6D12

What is inductor saturation?

Select	Answer
A	The inductor windings are over-coupled
B	The ability of the inductor's core to store magnetic energy has been exceeded
C	Adjacent inductors become over-coupled
D	The inductor's voltage rating is exceeded causing a flashover

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Two chips in each package (Dual In Package)
B	Low leakage doubly insulated package
C	Package mounts in a direct inverted position
D	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of voltage to current when exposed to light
B	The tendency of a battery to discharge when exposed to light
C	The conversion of light to electrical energy
D	The conversion of electrical energy to mechanical energy

31. - E7A02

What is the function of a decade counter?

Select	Answer
A	It decodes a binary number for display on a seven-segment LED display
B	It produces one output pulse for every 10 input pulses
C	It produces 10 output pulses for every input pulse
D	It decodes a decimal number for display on a seven-segment LED display

32. - E7B11

In Figure E7-1, what is the purpose of R3?

Select	Answer
A	Self bias
B	Fixed bias
C	Output load resistor
D	Emitter bypass

33. - E7C11

Which of the following describes a receiving filter's ability to reject signals occupying an adjacent channel?

Select	Answer
A	Phase response
B	Noise factor
C	Shape factor
D	Passband ripple

34. - E7D14

What is the purpose of connecting equal-value resistors across power supply filter capacitors connected in series?

Select	Answer
A	Equalize the voltage across each capacitor
B	All these choices are correct
C	Discharge the capacitors when voltage is removed
D	Provide a minimum load on the supply

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

36. - E7F08

What is the function of decimation?

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

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	47
C	94
D	24

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 direct digital synthesizer
D	A hybrid synthesizer

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	256
B	256 divided by the gain of the input amplifier
C	8 multiplied by the gain of the input amplifier
D	8

40. - E8B10

What is frequency division multiplexing?

Select	Answer
A	The transmitted signal is divided into packets of information
B	Two or more information streams are merged into a baseband, which then modulates the transmitter
C	The transmitted signal jumps from band to band at a predetermined rate
D	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter

41. - E8C12

What factors affect the bandwidth of a transmitted CW signal?

Select	Answer
A	All these choices are correct
B	IF bandwidth and Q
C	Modulation index and output power
D	Keying speed and shape factor (rise and fall time)

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Foreign language characters can be sent
B	Faster transmission rate
C	The signal can overpower interfering signals
D	Some types of errors can be detected

43. - E9A02

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	78.7 watts
B	286 watts
C	420 watts
D	1977 watts

44. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The computed feed point impedance may be incorrect
C	The antenna will become mechanically unstable
D	Ground conductivity will not be accurately modeled

45. - E9C11

How is the far-field elevation pattern of a vertically polarized antenna affected by being mounted over seawater versus soil?

Select	Answer
A	The low-angle radiation decreases
B	Fewer vertical angle lobes will be present
C	Additional higher vertical angle lobes will appear
D	The low-angle radiation increases

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	Wide flat copper strap
C	Resistive wire, such as spark plug wire
D	Stranded wire

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 capacitive
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 inductive

48. - E9F11

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

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

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning impedance values with regard to the prime center
C	Reassigning prime center with regard to the reactance axis
D	Reassigning reactance values with regard to the resistance axis

50. - E9H04

What is an advantage of placing a grounded electrostatic shield around a small loop direction-finding antenna?

Select	Answer
A	It increases signal strength by providing a better match to the feed line
B	It eliminates tracking errors caused by strong out-of-band signals
C	It eliminates unbalanced capacitive coupling to the surroundings, improving the nulls
D	It adds capacitive loading, increasing the bandwidth of the antenna

Figure E7-1