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

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1. - E0A08

What does SAR measure?

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

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	Notify the originating station that the communication does not comply with FCC rules
B	Notify the nearest FCC Field Engineers office
C	All these choices are correct
D	Discontinue forwarding the communication as soon as you become aware of it

3. - E1B11

What does PRB-1 require of regulations affecting amateur radio?

Select	Answer
A	Use of wireless devices in a vehicle is exempt from regulation
B	Reasonable accommodations of amateur radio must be made
C	Amateur radio operations must be permitted in any private residence
D	No limitations may be placed on antenna size or placement

4. - E1C02

Which of the following types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	Messages intended for users of the maritime satellite service
C	Communications incidental to the purpose of the amateur service and remarks of a personal nature
D	All these choices are correct

5. - E1D10

Which amateur stations are eligible to be telecommand stations of space stations (subject to the privileges of the class of operator license held by the control operator of the station)?

Select	Answer
A	Any amateur station designated by NASA
B	Any amateur station so designated by the ITU
C	All these choices are correct
D	Any amateur station so designated by the space station licensee

6. - E1E12

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

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

7. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	440 MHz - 450 MHz
B	222 MHz - 223 MHz
C	53 MHz - 54 MHz
D	420 MHz - 430 MHz

8. - E2A10

What type of satellite appears to stay in one position in the sky?

Select	Answer
A	HEO
B	Geomagnetic
C	LEO
D	Geostationary

9. - E2B11

What is the function of the Vertical Interval Signaling (VIS) code sent as part of an SSTV transmission?

Select	Answer
A	To identify the SSTV mode being used
B	To provide vertical synchronization
C	To lock the color burst oscillator in color SSTV images
D	To identify the call sign of the station transmitting

10. - E2C09

What type of equipment is commonly used to implement an amateur radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	An optical cable connection between the USB ports of 2 separate computers
C	A 440 MHz transceiver with a 9600 baud modem
D	A wireless router running custom firmware

11. - E2D06

Which of the following describes a method of establishing EME contacts?

Select	Answer
A	Storing and forwarding digital messages
B	High-speed CW identification to avoid fading
C	Time synchronous transmissions alternately from each station
D	Judging optimum transmission times by monitoring beacons reflected from the moon

12. - E2E11

What is the difference between direct FSK and audio FSK?

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

13. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	100 miles to 300 miles
B	10 miles to 50 miles
C	2500 miles
D	1200 miles

14. - E3B01

What is transequatorial propagation?

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

15. - E3C13

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

Select	Answer
A	Elliptical
B	Vertical
C	Horizontal
D	Circular

16. - E4A06

What is the effect of aliasing on a digital oscilloscope caused by setting the time base too slow?

Select	Answer
A	All signals will have a DC offset
B	A false, jittery low-frequency version of the signal is displayed
C	Excessive blanking occurs, which prevents display of the signal
D	Calibration of the vertical scale is no longer valid

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Input impedance
B	Reflection coefficient
C	Output impedance
D	All these choices are correct

18. - E4C07

What does the MDS of a receiver represent?

Select	Answer
A	The minimum discernible signal
B	The maximum detectable spectrum
C	The multiplex distortion stability
D	The meter display sensitivity

19. - E4D11

Why are odd-order intermodulation products, created within a receiver, of particular interest compared to other products?

Select	Answer
A	Odd-order products of two signals in the band of interest are also likely to be within the band
B	Odd-order products are an indication of poor image rejection
C	Odd-order products overload the IF filters
D	Odd-order intermodulation produces three products for every input signal within the band of interest

20. - E4E01

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

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

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower self-resonant frequency
B	Lower reactance
C	Higher self-resonant frequency
D	Lower losses

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

23. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By real and imaginary parts
B	By phase angle and magnitude
C	By X and R values
D	By Y and G values

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

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	N-type impurity
C	Acceptor impurity
D	Insulator impurity

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A negative resistance region
B	A constant voltage drop under conditions of varying current
C	A constant current drop under conditions of varying voltage
D	An internal capacitance that varies with the applied voltage

27. - E6C05

What is an advantage of CMOS logic devices over TTL devices?

Select	Answer
A	Differential output capability
B	Lower distortion
C	Immune to damage from static discharge
D	Lower power consumption

28. - E6D08

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

Select	Answer
A	Powdered-iron cores generally maintain their characteristics at higher currents
B	Powdered-iron cores use smaller diameter wire for the same inductance
C	Powdered-iron cores generally require fewer turns to produce a given inductance
D	Powdered-iron cores generally have greater initial permeability

29. - E6E05

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

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

30. - E6F01

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

Select	Answer
A	Electrons
B	Holes
C	Protons
D	Photons

31. - E7A02

What is the function of a decade counter?

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

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	Switching amplifiers use push-pull circuits
C	Switching amplifiers operate at higher voltages
D	The power transistor is at saturation or cutoff most of the time

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	Pi-networks provide balanced input and output
B	Pi-networks are more stable
C	The Q of Pi-networks can be controlled
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 controls the current supplied to the load
B	It provides a constant load for the voltage source
C	It provides negative feedback to improve regulation
D	It provides D1 with current

35. - E7E10

How does a diode envelope detector function?

Select	Answer
A	By breakdown of the Zener voltage
B	By sensing the change of reactance in the diode with respect to frequency
C	By mixing signals with noise in the transition region of the diode
D	By rectification and filtering of RF signals

36. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At the same rate as the highest frequency component of the signal
B	At least half the rate of the highest frequency component of the signal
C	At least twice the rate of the highest frequency component of the signal
D	At four times the rate of the highest frequency component of the signal

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	A RF amplifier used in the UHF and microwave regions
D	An amplifier used to increase the average output of frequency modulated amateur signals to the legal limit

38. - E7H02

What is a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Changes in oscillator frequency due to mechanical vibration
C	Distortion caused by RF pickup on the microphone cable
D	Excess loading of the microphone by an oscillator

39. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all its odd harmonics?

Select	Answer
A	Numerical analysis
B	Fourier analysis
C	Differential analysis
D	Vector analysis

40. - E8B07

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

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

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

Select	Answer
A	52 Hz
B	13 Hz
C	26 Hz
D	104 Hz

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 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 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. - 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	1977 watts
C	286 watts
D	420 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	Ground conductivity will not be accurately modeled
B	The computed feed point impedance may be incorrect
C	The antenna will become mechanically unstable
D	The resulting design will favor radiation of harmonic energy

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	A wideband vertical antenna constructed from precisely tapered aluminum tubing
B	An end-fed folded dipole antenna
C	A center-fed 1.25-wavelength antenna (two 5/8-wave elements in phase)
D	A portable antenna erected using two push support poles

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is unchanged if the loading coil is located at a voltage maximum point
B	It is unchanged if the loading coil is located at the feed point
C	It is increased
D	It is decreased

47. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

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

48. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically 1/2 wavelength long at 14.10 MHz?

Select	Answer
A	7.0 meters
B	10.6 meters
C	13.3 meters
D	8.5 meters

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical frequency
B	In fractions of transmission line electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of antenna electrical wavelength

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It has no clearly defined null
B	It has a bidirectional pattern
C	All these choices are correct
D	It is practical for use only on VHF and higher bands

Figure E7-2