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

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1. - E0A08

What does SAR measure?

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

2. - E1A14

Except in some parts of Alaska, what is the maximum power permitted on the 630 meter band?

Select	Answer
A	50 watts PEP
B	1 watt EIRP
C	5 watts EIRP
D	100 watts PEP

3. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You must obtain a construction permit from the airport zoning authority
B	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of the FCC rules
C	You must submit engineering drawings to the FAA
D	You must file an Environmental Impact Statement with the EPA before construction begins

4. - E1C07

At what level below a signal's mean power level is its bandwidth determined according to FCC rules?

Select	Answer
A	23 dB
B	6 dB
C	3 dB
D	26 dB

5. - E1D01

What is the definition of telemetry?

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

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. - E1F06

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

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

8. - E2A02

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

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

9. - E2B10

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone amplitude
B	Tone frequency
C	Sync frequency
D	Sync amplitude

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	No additional indicator is required
C	/ followed by the ARRL Section of the remote station
D	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located

11. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	15-second timed transmission sequences with stations alternating based on location
B	Use of special digital modes
C	All these choices are correct
D	Short transmissions with rapidly repeated call signs and signal reports

12. - E2E13

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

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

13. - E3A12

What is the cause of auroral activity?

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

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances
B	Long-path and short-path waves
C	Independent waves created in the ionosphere that are elliptically polarized
D	Refracted rays and reflected waves

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately four times the distance
B	By approximately 50 percent of the distance
C	By approximately twice the distance
D	By approximately 15 percent of the distance

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	Excessive blanking occurs, which prevents display of the signal
C	All signals will have a DC offset
D	A false, jittery low-frequency version of the signal is displayed

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

18. - E4C01

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

Select	Answer
A	It can combine with strong signals on nearby frequencies to generate interference
B	It can affect the receiver's frequency calibration
C	It decreases receiver third-order intercept point
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 provide a range of AGC time constants
C	To store often-used frequencies
D	To allow selection of the optimum RF amplifier device

20. - E4E05

How can radio frequency interference from an AC motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a high-pass filter in series with the motor's power leads
D	By installing a bypass capacitor in series with the motor leads

21. - E5A01

What can cause the voltage across reactances in a series RLC circuit to be higher than the voltage applied to the entire circuit?

Select	Answer
A	Capacitance
B	Resistance
C	Conductance
D	Resonance

22. - E5B06

What is susceptance?

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

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	Polar coordinates
B	Maidenhead grid
C	Elliptical coordinates
D	Faraday grid

24. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in wire resistance in an inductor
B	Power lost because of capacitor leakage
C	Wattless, nonproductive power
D	Power consumed in circuit Q

25. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that has no current flow between source and drain when no gate voltage is applied
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. - E6B09

What is a common use for point-contact diodes?

Select	Answer
A	As a high-voltage rectifier
B	As a constant current source
C	As an RF detector
D	As a constant voltage source

27. - E6C01

What is the function of hysteresis in a comparator?

Select	Answer
A	To allow the comparator to be used with AC input signals
B	To increase the sensitivity
C	To prevent input noise from causing unstable output signals
D	To cause the output to change states continually

28. - E6D05

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

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

29. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	44 dBm
C	-20 dBm
D	2 dB

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It stays the same
B	It becomes unstable
C	It decreases
D	It increases

31. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Astable multivibrator
B	T flip-flop
C	Monostable multivibrator
D	J-K flip-flop

32. - E7B06

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

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

33. - E7C11

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

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

34. - E7D03

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

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

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	A circuit for filtering two closely adjacent signals
C	A circuit for detecting FM signals
D	An FM generator circuit

36. - E7F12

Which of the following is an advantage of a Finite Impulse Response (FIR) filter vs an Infinite Impulse Response (IIR) digital filter?

Select	Answer
A	FIR filters can respond faster to impulses
B	FIR filters are easier to implement for a given set of passband rolloff requirements
C	All these choices are correct
D	FIR filters can delay all frequency components of the signal by the same amount

37. - E7G12

What is an operational amplifier?

Select	Answer
A	A high-gain, direct-coupled differential amplifier with very high input impedance and very low output impedance
B	A digital audio amplifier whose characteristics are determined by components external to the amplifier
C	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit
D	A RF amplifier used in the UHF and microwave regions

38. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Colpitts and Hartley
B	Pierce and Zener
C	Armstrong and deForest
D	Negative feedback and balanced feedback

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Very low power consumption decreases frequency drift
B	All these choices are correct
C	Immunity to out-of-sequence coding reduces spurious responses
D	Very high speed allows digitizing high frequencies

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	High-speed digital modes
B	Extremely low-power contacts
C	EME
D	OFDM signals are not allowed on amateur bands

41. - E8C07

What is the bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	4.8 kHz
B	9.6 kHz
C	15.36 kHz
D	5.76 kHz

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 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
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 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

43. - E9A03

What is the radiation resistance of an antenna?

Select	Answer
A	The resistance in the atmosphere that an antenna must overcome to be able to radiate a signal
B	The value of a resistance that would dissipate the same amount of power as that radiated from an antenna
C	The combined losses of the antenna elements and feed line
D	The specific impedance of the antenna

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	24 dB
B	18 dB
C	36 dB
D	14 dB

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

46. - E9D01

How much does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	3 dB
B	2 dB
C	6 dB
D	4 dB

47. - E9E01

What system matches a higher-impedance transmission line to a lower-impedance antenna by connecting the line to the driven element in two places spaced a fraction of a wavelength each side of element center?

Select	Answer
A	The stub matching system
B	The delta matching system
C	The gamma matching system
D	The omega matching system

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	Dielectric materials used in the line
B	The center conductor resistivity
C	The termination impedance
D	The line length

49. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Impedance and SWR values in transmission lines
B	Beam headings and radiation patterns
C	Satellite azimuth and elevation bearings
D	Trigonometric functions

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 E9-1