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

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1. - E0A01

What is the primary function of an external earth connection or ground rod?

Select	Answer
A	Reduce RFI to telephones and home entertainment systems
B	Reduce received noise
C	Reduce RF current flow between pieces of equipment
D	Lightning protection

2. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operator of the packet bulletin board station
C	The control operators of all the stations in the system not authenticating the source from which they accept communications
D	The control operators of all the stations in the system

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	Only when transmitting RTTY or data emissions
B	When approved by the National Telecommunication and Information Administration
C	When agreed upon by the sending or receiving station
D	Never

5. - E1D01

What is the definition of telemetry?

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

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license
B	Providing amateur operator license examination preparation training materials
C	No expenses are authorized for reimbursement
D	Teaching an amateur operator license examination preparation course

7. - E1F04

Which of the following geographic descriptions approximately describes "Line A"?

Select	Answer
A	A line roughly parallel to and south of the border between the U.S. and Canada
B	A line roughly parallel to and west of the U.S. Atlantic coastline
C	A line roughly parallel to and east of the U.S. Pacific coastline
D	A line roughly parallel to and north of the border between the U.S. and Mexico

8. - E2A01

What is the direction of an ascending pass for an amateur satellite?

Select	Answer
A	From east to west
B	From south to north
C	From west to east
D	From north to south

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Specific tone frequencies
B	Specific tone amplitudes
C	Elapsed time
D	A two-tone signal

10. - E2C07

What is the Cabrillo format?

Select	Answer
A	The most common set of contest rules
B	The rules of order for meetings between contest sponsors
C	A standard for submission of electronic contest logs
D	A method of exchanging information during a contest QSO

11. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	JT65
B	PACTOR III
C	MSK144
D	Olivia

12. - E2E09

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

Select	Answer
A	PACTOR
B	PSK31
C	RTTY
D	MT63

13. - E3A12

What is the cause of auroral activity?

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

14. - E3B04

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

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

15. - E3C12

How does the maximum range of ground-wave propagation change when the signal frequency is increased?

Select	Answer
A	It decreases
B	It stays the same
C	It peaks at roughly 14 MHz
D	It increases

16. - E4A11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Loosely couple the antenna and a dummy load to the analyzer
B	Connect the antenna feed line directly to the analyzer's connector
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Loosely couple the analyzer near the antenna base

17. - E4B05

What three test loads are used to calibrate an RF vector network analyzer?

Select	Answer
A	Short circuit, open circuit, and resonant circuit
B	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
C	Short circuit, open circuit, and 50 ohms
D	50 ohms, 75 ohms, and 90 ohms

18. - E4C03

What is the term for the suppression in an FM receiver of one signal by another stronger signal on the same frequency?

Select	Answer
A	Cross-modulation interference
B	Frequency discrimination
C	Capture effect
D	Desensitization

19. - E4D02

Which of the following describes problems caused by poor dynamic range in a receiver?

Select	Answer
A	Oscillator instability and severe audio distortion of all but the strongest received signals
B	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
C	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
D	Spurious signals caused by cross-modulation and desensitization from strong adjacent signals

20. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Received audio in the speech range might have an echo effect
C	Nearby signals may appear to be excessively wide even if they meet emission standards
D	FM signals can no longer be demodulated

21. - E5A07

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Select	Answer
A	Maximum
B	L/R
C	Minimum
D	R/L

22. - E5B02

What letter is commonly used to represent susceptance?

Select	Answer
A	X
B	Y
C	B
D	G

23. - E5C11

Which point in Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and an 18-microhenry inductor at 3.505 MHz?

Select	Answer
A	Point 1
B	Point 3
C	Point 8
D	Point 7

24. - E5D07

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	355 W
B	704 W
C	252 W
D	1.42 mW

25. - E6A06

What is the beta of a bipolar junction transistor?

Select	Answer
A	The switching speed
B	The frequency at which the current gain is reduced to 0.707
C	The breakdown voltage of the base to collector junction
D	The change in collector current with respect to base current

26. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	A sub-harmonic pump signal
B	Capacitance of an RF coupling capacitor
C	Reverse voltage larger than the RF signal
D	Forward DC bias current

27. - E6C09

What is a Programmable Logic Device (PLD)?

Select	Answer
A	A logic circuit that can be modified during use
B	Programmable equipment used for testing digital logic integrated circuits
C	A programmable collection of logic gates and circuits in a single integrated circuit
D	A type of transistor whose gain can be changed by digital logic circuits

28. - E6D05

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

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

29. - E6E10

What advantage does surface-mount technology offer at RF compared to using through-hole components?

Select	Answer
A	Smaller circuit area
B	Components have less parasitic inductance and capacitance
C	Shorter circuit-board traces
D	All these choices are correct

30. - E6F11

What is the approximate open-circuit voltage produced by a fully illuminated silicon photovoltaic cell?

Select	Answer
A	1.5 V
B	0.5 V
C	12 V
D	0.1 V

31. - E7A06

What is a characteristic of a monostable multivibrator?

Select	Answer
A	It switches momentarily to the opposite binary state and then returns to its original state after a set time
B	It stores one bit of data in either a 0 or 1 state
C	It produces a continuous square wave oscillating between 1 and 0
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	Increased overall intelligibility
B	Signal distortion and excessive bandwidth
C	Signal inversion
D	Reduced intermodulation products

33. - E7C10

Which of the following filters would be the best choice for use in a 2 meter band repeater duplexer?

Select	Answer
A	A cavity filter
B	A crystal filter
C	An L-C filter
D	A DSP filter

34. - E7D10

What is the primary reason that a high-frequency switching type high-voltage power supply can be both less expensive and lighter in weight than a conventional power supply?

Select	Answer
A	The inverter design does not require any output filtering
B	The high frequency inverter design uses much smaller transformers and filter components for an equivalent power output
C	It uses a large power factor compensation capacitor to recover power from the unused portion of the AC cycle
D	It uses a diode bridge rectifier for increased output

35. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	1.414 and 0.707 times the input frequency
B	Two and four times the original frequency
C	The square root of the product of input frequencies
D	The two input frequencies along with their sum and difference frequencies

36. - E7F08

What is the function of decimation?

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

37. - E7G04

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

Select	Answer
A	The differential input voltage needed to bring the open loop output voltage to zero
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
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. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	NP0 capacitors
B	Toroidal inductors
C	Non-inductive resistors
D	Wirewound resistors

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	Fourier analysis
B	Vector analysis
C	Differential analysis
D	Numerical analysis

40. - E8B01

What is the modulation index of an FM signal?

Select	Answer
A	The bandwidth of the transmitted signal divided by the modulating signal frequency
B	The ratio of modulating signal amplitude to frequency deviation
C	The type of modulation used by the transmitter
D	The ratio of frequency deviation to modulating signal frequency

41. - E8C11

What is the relationship between symbol rate and baud?

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

42. - E8D03

How does the spread spectrum technique of frequency hopping work?

Select	Answer
A	If interference is detected by the receiver it will signal the transmitter to wait until the frequency is clear
B	A binary bit stream is used to shift the phase of an RF carrier very rapidly in a pseudorandom sequence
C	If interference is detected by the receiver it will signal the transmitter to change frequencies
D	The frequency of the transmitted signal is changed very rapidly according to a pseudorandom sequence also used by the receiving station

43. - E9A04

Which of the following factors affect the feed point impedance of an antenna?

Select	Answer
A	The settings of an antenna tuner at the transmitter
B	Antenna height
C	Transmission line length
D	The input power level

44. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	25 degrees
B	75 degrees
C	7.5 degrees
D	45 degrees

45. - E9C09

Which of the following describes a G5RV antenna?

Select	Answer
A	A phased array antenna consisting of multiple loops
B	A multi-band trap antenna
C	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
D	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a�4:1 balun

46. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Improved radiation efficiency
B	Greater structural strength
C	Lower Q
D	Higher losses

47. - E9E06

Which of these feed line impedances would be suitable for constructing a quarter-wave Q-section for matching a 100-ohm loop to 50-ohm feed line?

Select	Answer
A	50 ohms
B	450 ohms
C	62 ohms
D	75 ohms

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

49. - E9G09

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

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

50. - E9H05

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

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

Figure E5-1

Figure E9-2