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

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1. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Hearing loss caused by high voltage corona discharge
B	Localized heating of the body from RF exposure in excess of the MPE limits
C	Blood clotting from the intense magnetic field
D	Ingestion of ozone gas from the cooling system

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	14.349 MHz
B	14.100 MHz
C	14.070 MHz
D	14.149 MHz

3. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An amateur station transmission made without the proper call sign identification
B	A signal transmitted to prevent its detection by any station other than the intended recipient
C	An emission outside the signal's necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
D	Any transmitted signal that unintentionally interferes with another licensed radio station

4. - E1C01

What is the maximum bandwidth for a data emission on 60 meters?

Select	Answer
A	170 Hz
B	2.8 kHz
C	1.5 kHz
D	60 Hz

5. - E1D05

What must be posted at the station location of a station being operated by telecommand on or within 50 km of the earth's surface?

Select	Answer
A	A label with the name, address, and telephone number of the station licensee
B	A label with the name, address, and telephone number of the control operator
C	A photocopy of the station license
D	All these choices are correct

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Friends of the VE
B	Relatives of the VE as listed in the FCC rules
C	Employees of the VE
D	All these choices are correct

7. - E1F06

Under what circumstances might the FCC issue a Special Temporary Authority (STA) to an amateur station?

Select	Answer
A	To provide additional spectrum for personal use
B	To provide for experimental amateur communications
C	To provide temporary operation while awaiting normal licensing
D	To allow regular operation on Land Mobile channels

8. - E2A03

How is the signal inverted by an inverting linear transponder?

Select	Answer
A	The signal is detected and remodulated on the reverse sideband
B	The signal is reduced to I and Q components and the Q component is filtered out
C	The signal is passed through a non-linear filter
D	The signal is passed through a mixer and the difference rather than the sum is transmitted

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning each field from bottom to top
B	By scanning lines from left to right in one field and right to left in the next
C	By scanning two fields simultaneously
D	By scanning odd numbered lines in one field and even numbered lines in the next

10. - E2C01

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control and the remote transmitter is located in the U.S.?

Select	Answer
A	/R# where # is the district of the remote station
B	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
C	/ followed by the ARRL Section of the remote station
D	No additional indicator is required

11. - E2D05

What is one advantage of the JT65 mode?

Select	Answer
A	The ability to decode signals which have a very low signal-to-noise ratio
B	Uses only a 65 Hz bandwidth
C	Permits fast-scan TV transmissions over narrow bandwidth
D	Easily copied by ear if necessary

12. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	MT63
B	PSK31
C	RTTY
D	PACTOR

13. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	The returning echo is several hertz lower in frequency than the transmitted signal
B	A fluttery irregular fading
C	A gradual loss of signal as the sun rises
D	A slow change in the pitch of the CW signal

14. - E3B06

Which of the following amateur bands most frequently provides long-path propagation?

Select	Answer
A	10 meters
B	20 meters
C	80 meters
D	6 meters

15. - E3C13

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

Select	Answer
A	Horizontal
B	Circular
C	Vertical
D	Elliptical

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Sampling rate of the analog-to-digital converter
B	Q of the circuit
C	Amount of memory
D	All these choices are correct

17. - E4B02

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
B	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
C	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
D	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test

18. - E4C15

What is reciprocal mixing?

Select	Answer
A	Two digital signals combining from alternate time slots
B	In-phase signals cancelling in a mixer resulting in loss of receiver sensitivity
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. - 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	Utilizing a Class C final amplifier
B	A band-pass filter in the feed line between the transmitter and receiver
C	A properly terminated circulator at the output of the repeater's transmitter
D	Utilizing a Class D final amplifier

20. - E4E08

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

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

21. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 1 divided by the quantity 2 times pi, multiplied by the square root of inductance L multiplied by capacitance C
B	It is at a minimum
C	It equals 2 multiplied by pi, multiplied by frequency, multiplied by inductance
D	It is at a maximum

22. - E5B05

What happens to the magnitude of a pure reactance when it is converted to a susceptance?

Select	Answer
A	It is unchanged
B	It is shifted by 90 degrees
C	It becomes the reciprocal
D	The sign is reversed

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	Faraday grid
C	Polar coordinates
D	Maidenhead grid

24. - E5D05

What is the power factor of an RL circuit having a 30-degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	0.577
C	1.73
D	0.866

25. - E6A07

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

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

26. - E6B06

Which of the following is a common use of a Schottky diode?

Select	Answer
A	As a constant voltage reference in a power supply
B	As a VHF/UHF mixer or detector
C	As a variable capacitance in an automatic frequency control circuit
D	As a rectifier in high current power supplies

27. - E6C03

What is tri-state logic?

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

28. - E6D12

What is inductor saturation?

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

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	The ability to retrieve information from a single signal even in the presence of other strong signals
B	Plate current that is controlled by a control grid
C	Nearly infinite gain, very high input impedance, and very low output impedance
D	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range

30. - E6F10

What is the most common type of photovoltaic cell used for electrical power generation?

Select	Answer
A	Cadmium Sulfide
B	Selenium
C	Silicon
D	Copper oxide

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It produces a continuous square wave oscillating between 1 and 0
B	It stores one bit of data in either a 0 or 1 state
C	It switches momentarily to the opposite binary state and then returns to its original state after a set time
D	It maintains a constant output voltage, regardless of variations in the input voltage

32. - E7B07

Which of the following is a likely result when a Class C amplifier is used to amplify a single-sideband phone signal?

Select	Answer
A	Signal inversion
B	Signal distortion and excessive bandwidth
C	Increased overall intelligibility
D	Reduced intermodulation products

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Extremely sharp cutoff with one or more notches in the stop band
C	Gradual passband rolloff with extreme stop band ripple
D	Extremely flat response over its pass band with gradually rounded stop band corners

34. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-2?

Select	Answer
A	It is a brute force filter for the output
B	To provide fixed DC bias for Q1
C	It bypasses rectifier output ripple around D1
D	To self-resonate at the hum frequency

35. - E7E05

What circuit is added to an FM transmitter to boost the higher audio frequencies?

Select	Answer
A	A heterodyne suppressor
B	A pre-emphasis network
C	A de-emphasis network
D	A heterodyne enhancer

36. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	A frequency synthesizer removes the unwanted sidebands
B	Mixing products are converted to voltages and subtracted by adder circuits
C	Varying quartz crystal characteristics emulated in digital form
D	Signals are combined in quadrature phase relationship

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The potential between the amplifier input terminals of the op-amp in an open loop condition
D	The output voltage of the op-amp minus its input voltage

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. - E8A05

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

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

40. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
B	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
C	Two or more signals are arranged to share discrete time slots of a data transmission
D	Two or more signals are quadrature modulated to increase bandwidth efficiency

41. - E8C11

What is the relationship between symbol rate and baud?

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

42. - E8D10

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

Select	Answer
A	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
B	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
C	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
D	Baudot uses 7 data bits per character, ASCII uses 8; Baudot has no letters/figures shift code, ASCII uses 2 letters/figures shift codes

43. - E9A06

What is the effective radiated power relative to a dipole of a repeater station with 200 watts transmitter power output, 4 dB feed line loss, 3.2 dB duplexer loss, 0.8 dB circulator loss, and 10 dBd antenna gain?

Select	Answer
A	300 watts
B	2000 watts
C	126 watts
D	317 watts

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a series of segments, each having a distinct value of voltage across it
B	A wire is modeled as a single sine-wave voltage source
C	A wire is modeled as a single sine-wave current generator
D	A wire is modeled as a series of segments, each having a uniform value of current

45. - E9C13

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with increasing height above ground?

Select	Answer
A	The horizontal beamwidth decreases
B	The takeoff angle of the lowest elevation lobe decreases
C	The takeoff angle of the lowest elevation lobe increases
D	The horizontal beamwidth increases

46. - E9D10

What happens to feed-point impedance at the base of a fixed length HF mobile antenna when operated below its resonant frequency?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance increases
B	The radiation resistance decreases and the capacitive reactance decreases
C	The radiation resistance increases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance decreases

47. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The omega match
B	The stub match
C	The gamma match
D	The delta match

48. - E9F04

What impedance does a 1/2-wavelength transmission line present to a generator when the line is shorted at the far end?

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

49. - E9G09

What third family of circles is often added to a Smith chart during the process of solving problems?

Select	Answer
A	Coaxial-length circles
B	Radiation-pattern circles
C	Standing wave ratio circles
D	Antenna-length circles

50. - E9H10

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

Select	Answer
A	By winding adjacent turns in opposing directions
B	By increasing the number of turns and/or the area
C	By reducing the permeability of the loop shield
D	By utilizing high impedance wire for the coupling loop

Figure E7-2