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

2. - E1A11

Which of the following describes authorization or licensing required when operating an amateur station aboard a U.S.-registered vessel in international waters?

Select	Answer
A	Any FCC-issued amateur license
B	Only General Class or higher amateur licenses
C	Any amateur license with an FCC Marine or Aircraft endorsement
D	An unrestricted Radiotelephone Operator Permit

3. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historic Places?

Select	Answer
A	A proposal must be submitted to the National Park Service
B	An Environmental Assessment must be submitted to the FCC
C	A form FSD-15 must be submitted to the Department of the Interior
D	A letter of intent must be filed with the Environmental Protection Agency

4. - E1C03

How do the control operator responsibilities of a station under automatic control differ from one under local control?

Select	Answer
A	Under automatic control there is no control operator
B	Under local control a control operator is not required to be present at a control point
C	Under local control there is no control operator
D	Under automatic control the control operator is not required to be present at the control point

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

Select	Answer
A	2 meters
B	6 meters and 2 meters
C	6 meters, 2 meters, and 1.25 meters
D	2 meters and 1.25 meters

6. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to administer amateur operator license examinations
B	An organization that has entered into an agreement with the FCC to coordinate, prepare, and administer amateur operator license examinations
C	The person who has entered into an agreement with the FCC to be the VE session manager
D	A person who has volunteered to prepare amateur operator license examinations

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When the total money involved does not exceed $25
B	When transmitting international third-party communications
C	When neither the amateur nor his or her employer has a pecuniary interest in the communications
D	When the control operator is employed by the FCC or another government agency

8. - E2A01

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

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

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. - 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	No additional indicator is required
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	/R# where # is the district of the remote station

11. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Acknowledgement
B	Disconnect
C	Connect
D	Unnumbered Information

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 can transmit faster baud rates
D	Direct FSK occupies less bandwidth

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	RTTY
B	SSB
C	FM
D	CW

14. - E3B10

Why is chordal hop propagation desirable?

Select	Answer
A	The signal experiences less loss compared to multi-hop using Earth as a reflector
B	Signals travel faster along ionospheric chords
C	Atmospheric noise is lower in the direction of chordal hop propagation
D	The MUF for chordal hop propagation is much lower than for normal skip propagation

15. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar emission at 304 GHz, correlated to x-ray flare levels
B	The ratio of x-ray flux to radio flux, correlated to sunspot number
C	UV emissions at 304 angstroms, correlated to the solar flux index
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

16. - E4A06

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

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

17. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	The transmitter is not properly neutralized
B	There is more power going into the antenna
C	There is an impedance mismatch between the antenna and feed line
D	There is possibly a short to ground in the feed line

18. - E4C07

What does the MDS of a receiver represent?

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

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Nonlinear circuits or devices
B	Positive feedback
C	Lack of neutralization
D	Too little gain

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
B	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead
C	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
D	By installing a noise suppression resistor and a blocking capacitor in both leads

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	47.3 kHz
B	23.67 kHz
C	315.6 Hz
D	157.8 Hz

22. - E5B06

What is susceptance?

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

23. - E5C02

How are impedances described in polar coordinates?

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

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	0.866
B	0.577
C	0.5
D	1.73

25. - E6A05

How does DC input impedance at the gate of a field-effect transistor compare with the DC input impedance of a bipolar transistor?

Select	Answer
A	An FET has lower input impedance
B	They are both high impedance
C	An FET has higher input impedance
D	They are both low impedance

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	Reverse voltage larger than the RF signal
C	Forward DC bias current
D	Capacitance of an RF coupling capacitor

27. - E6C03

What is tri-state logic?

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

28. - E6D10

What is a primary advantage of using a toroidal core instead of a solenoidal core in an inductor?

Select	Answer
A	Toroidal cores make it easier to couple the magnetic energy into other components
B	Toroidal cores exhibit greater hysteresis
C	Toroidal cores have lower Q characteristics
D	Toroidal cores confine most of the magnetic field within the core material

29. - E6E07

What type of transmission line is used for connections to MMICs?

Select	Answer
A	Microstrip
B	Circular waveguide
C	Parallel wire
D	Miniature coax

30. - E6F07

What is a solid-state relay?

Select	Answer
A	A device that uses semiconductors to implement the functions of an electromechanical relay
B	A semiconductor passive delay line
C	A relay using transistors to drive the relay coil
D	A mechanical relay that latches in the on or off state each time it is pulsed

31. - E7A05

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

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

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

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

33. - E7C09

What is a crystal lattice filter?

Select	Answer
A	An audio filter made with four quartz crystals that resonate at 1 kHz intervals
B	A filter using lattice-shaped quartz crystals for high-Q performance
C	A filter with narrow bandwidth and steep skirts made using quartz crystals
D	A power supply filter made with interlaced quartz crystals

34. - E7D07

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

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

35. - E7E03

What is a frequency discriminator stage in a FM receiver?

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

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

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	0.23 volts
D	2.3 volts

38. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Photovoltaic conversion, optical coupling
B	Frequency synthesis, FM demodulation
C	Comparison of two digital input signals, digital pulse counter
D	Wide-band AF and RF power amplification

39. - E8A09

How many different input levels can be encoded by an analog-to-digital converter with 8-bit resolution?

Select	Answer
A	8
B	256
C	8 multiplied by the gain of the input amplifier
D	256 divided by the gain of the input amplifier

40. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A frequency modulation technique that uses non-harmonically related frequencies
B	A bandwidth compression technique using Fourier transforms
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A digital mode for narrow-band, slow-speed transmissions

41. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special polynomial codes provide automatic correction
B	Special binary codes provide automatic correction
C	If errors are detected, redundant data is substituted
D	If errors are detected, a retransmission is requested

42. - E8D06

What is the advantage of including parity bits in ASCII characters?

Select	Answer
A	Faster transmission rate
B	The signal can overpower interfering signals
C	Foreign language characters can be sent
D	Some types of errors can be detected

43. - E9A12

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 6 dB gain over an isotropic antenna?

Select	Answer
A	6.0 dB
B	2.79 dB
C	3.85 dB
D	8.15 dB

44. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the beamwidth?

Select	Answer
A	30 degrees
B	25 degrees
C	75 degrees
D	50 degrees

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A type of ground-plane antenna
B	A dipole configured to provide forward gain
C	A half-wave dipole with an additional parallel wire connecting its two ends
D	A dipole one-quarter wavelength long

46. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To increase the SWR bandwidth
C	To lower the losses
D	To cancel capacitive reactance

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 delta matching system
B	The gamma matching system
C	The omega matching system
D	The stub matching system

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

49. - E9G08

What is the process of normalization with regard to a Smith chart?

Select	Answer
A	Reassigning resistance values with regard to the reactance axis
B	Reassigning impedance values with regard to the prime center
C	Reassigning reactance values with regard to the resistance axis
D	Reassigning prime center with regard to the reactance axis

50. - E9H03

What is Receiving Directivity Factor (RDF)?

Select	Answer
A	Forward gain compared to average gain over the entire hemisphere
B	Forward gain compared to the gain in the reverse direction
C	Relative directivity compared to a dipole
D	Relative directivity compared to isotropic

Figure E7-2

Figure E7-3

Figure E9-1