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 RF current flow between pieces of equipment
C	Lightning protection
D	Reduce received noise

2. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
C	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station participating in the Military Auxiliary Radio System (MARS)
B	Any FCC-licensed amateur station except a Technician Class
C	Only those club stations licensed to Amateur Extra Class operators
D	Any FCC-licensed amateur station certified by the responsible civil defense organization for the area served

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	3 dB
C	6 dB
D	26 dB

5. - E1D04

Which of the following is required in the identification transmissions from a balloon-borne telemetry station?

Select	Answer
A	The output power of the balloon transmitter
B	The station's six-character Maidenhead grid locator
C	All these choices are correct
D	Call sign

6. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
B	A sentence of up to one year in prison
C	All these choices are correct
D	A fine of up to $1000 per occurrence

7. - E1F04

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

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

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To avoid interfering with terrestrial QSOs
B	To avoid reducing the downlink power to all other users
C	To prevent creating errors in the satellite telemetry
D	To prevent the satellite from emitting out-of-band signals

9. - E2B12

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

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

10. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Special event contacts between stations in the U.S.
B	Contacts using tactical call signs
C	Contacts between a U.S. station and a non-U.S. station
D	Repeater contacts between U.S. club members

11. - E2D03

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

Select	Answer
A	Olivia
B	MSK144
C	PACTOR III
D	JT65

12. - E2E01

Which of the following types of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	Spread spectrum
C	Pulse modulation
D	FSK

13. - E3A12

What is the cause of auroral activity?

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

14. - E3B03

What is the best time of day for transequatorial propagation?

Select	Answer
A	Afternoon or early evening
B	Late at night
C	Morning
D	Noon

15. - E3C13

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

Select	Answer
A	Horizontal
B	Vertical
C	Elliptical
D	Circular

16. - E4A01

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

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

17. - E4B10

Which of the following methods measures intermodulation distortion in an SSB transmitter?

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

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The noise figure of a 1 Hz bandwidth receiver
B	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
C	The minimum detectable signal as a function of receive frequency
D	The galactic noise contribution to minimum detectable signal

19. - E4D10

What does a third-order intercept level of 40 dBm mean with respect to receiver performance?

Select	Answer
A	The receiver can tolerate signals up to 40 dB above the noise floor without producing third-order intermodulation products
B	A pair of 40 dBm input signals will theoretically generate a third-order intermodulation product that has the same output amplitude as either of the input signals
C	A pair of 1 mW input signals will produce a third-order intermodulation product that is 40 dB stronger than the input signal
D	Signals less than 40 dBm will not generate audible third-order intermodulation products

20. - E4E02

Which of the following types of noise can often be reduced with a digital signal processing noise filter?

Select	Answer
A	Ignition noise
B	All these choices are correct
C	Power line noise
D	Broadband white noise

21. - E5A11

What is the half-power bandwidth of a resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	315.6 Hz
B	47.3 kHz
C	23.67 kHz
D	157.8 Hz

22. - E5B05

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

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

23. - E5C01

Which of the following represents capacitive reactance in rectangular notation?

Select	Answer
A	Omega
B	+jX
C	-jX
D	Delta

24. - E5D11

What is the power factor of an RL circuit having a 60-degree phase angle between the voltage and the current?

Select	Answer
A	1.414
B	1.73
C	0.5
D	0.866

25. - E6A06

What is the beta of a bipolar junction transistor?

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

26. - E6B08

Which of the following is a Schottky barrier diode?

Select	Answer
A	Metal-semiconductor junction
B	PIN junction
C	Electrolytic rectifier
D	Thermionic emission diode

27. - E6C03

What is tri-state logic?

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

28. - E6D02

What is the equivalent circuit of a quartz crystal?

Select	Answer
A	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in parallel
B	Motional capacitance, motional inductance, loss resistance, and a capacitor representing electrode and stray capacitance all in series
C	Motional inductance and loss resistance in series, paralleled with motional capacitance and a capacitor representing electrode and stray capacitance
D	Motional capacitance, motional inductance, and loss resistance in series, all in parallel with a shunt capacitor representing electrode and stray capacitance

29. - E6E06

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

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

30. - E6F01

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

Select	Answer
A	Protons
B	Holes
C	Electrons
D	Photons

31. - E7A10

What is a truth table?

Select	Answer
A	A table of logic symbols that indicate the logic states of an op-amp
B	A list of inputs and corresponding outputs for a digital device
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

32. - E7B09

Which of the following describes how the loading and tuning capacitors are to be adjusted when tuning a vacuum tube RF power amplifier that employs a Pi-network output circuit?

Select	Answer
A	The tuning capacitor is set to maximum capacitance and the loading capacitor is adjusted for minimum plate permissible current
B	The loading capacitor is adjusted to minimum plate current while alternately adjusting the tuning capacitor for maximum allowable plate current
C	The loading capacitor is set to maximum capacitance and the tuning capacitor is adjusted for minimum allowable plate current
D	The tuning capacitor is adjusted for minimum plate current, and the loading capacitor is adjusted for maximum permissible plate current

33. - E7C05

Which filter type is described as having ripple in the passband and a sharp cutoff?

Select	Answer
A	A Butterworth filter
B	A passive op-amp filter
C	A Chebyshev filter
D	An active LC filter

34. - E7D04

Which of the following types of linear voltage regulator usually make the most efficient use of the primary power source?

Select	Answer
A	A series current source
B	A shunt current source
C	A series regulator
D	A shunt regulator

35. - E7E07

What is meant by the term "baseband" in radio communications?

Select	Answer
A	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
B	The unmodulated bandwidth of the transmitted signal
C	The frequency range occupied by a message signal prior to modulation
D	The lowest frequency band that the transmitter or receiver covers

36. - E7F11

What sets the minimum detectable signal level for a direct-sampling SDR receiver in the absence of atmospheric or thermal noise?

Select	Answer
A	Sample clock phase noise
B	Missing codes and jitter
C	Data storage transfer rate
D	Reference voltage level and sample width in bits

37. - E7G09

What will be the output voltage of the circuit shown in Figure E7-3 if R1 is 1000 ohms, RF is 10,000 ohms, and 0.23 volts DC is applied to the input?

Select	Answer
A	0.23 volts
B	2.3 volts
C	-2.3 volts
D	-0.23 volts

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

Select	Answer
A	Pierce, Fenner and Beane
B	Taft, Hartley and Pierce
C	Taft, Pierce and negative feedback
D	Colpitts, Hartley and Pierce

39. - E8A10

What is the purpose of a low-pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out-of-sequence codes from the input
B	Remove harmonics from the output caused by the discrete analog levels generated
C	All these choices are correct
D	Lower the input bandwidth to increase the effective resolution

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	High-speed digital modes
D	Extremely low-power contacts

41. - E8C05

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

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

42. - E8D05

What is the most common method of reducing key clicks?

Select	Answer
A	High-pass filters at the transmitter output
B	Increase keying waveform rise and fall times
C	Low-pass filters at the transmitter output
D	Reduce keying waveform rise and fall times

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Effective radiated power
B	Apparent power
C	Half-power bandwidth
D	Power factor

44. - E9B08

What is the far field of an antenna?

Select	Answer
A	The region of the ionosphere where radiated power is not refracted
B	The region where radiated power dissipates over a specified time period
C	The region where radiated field strengths are constant
D	The region where the shape of the antenna pattern is independent of distance

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A dipole constructed from zip cord
B	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
C	An end-fed dipole antenna
D	An omni-directional antenna commonly used for satellite communications

46. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	More common-mode current is present on the feed line
B	SWR bandwidth decreases
C	SWR bandwidth increases
D	Gain is reduced

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	75 ohms
B	450 ohms
C	50 ohms
D	62 ohms

48. - E9F05

What is the approximate physical length of a solid polyethylene dielectric coaxial transmission line that is electrically 1/4 wavelength long at 14.1 MHz?

Select	Answer
A	3.5 meters
B	4.3 meters
C	5.3 meters
D	10.6 meters

49. - E9G05

Which of the following is a common use for a Smith chart?

Select	Answer
A	Determine the loss/100 feet of a transmission line, given the velocity factor and conductor materials
B	Determine the impedance of a transmission line, given the physical dimensions
C	Determine the length and position of an impedance matching stub
D	Determine the gain of an antenna given the physical and electrical parameters

50. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	Antenna headings from several different receiving locations are used to locate the signal source
B	The geometric angles of sky waves from the source are used to determine its position
C	A fixed receiving station uses three different antennas to plot the location of the signal source
D	A fixed receiving station plots three headings to the signal source

Figure E7-3