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

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1. - E0A05

What is one of the potential hazards of operating in the amateur radio microwave bands?

Select	Answer
A	The extremely high frequency energy can damage the joints of antenna structures
B	Microwaves often travel long distances by ionospheric reflection
C	The high gain antennas commonly used can result in high exposure levels
D	Microwaves are ionizing radiation

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	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license
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	Its operation must be approved by the master of the ship or the pilot in command of the aircraft

3. - E1B09

Which amateur stations may be operated under RACES rules?

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

4. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	5 minutes
B	3 minutes
C	30 seconds
D	10 minutes

5. - E1D07

Which HF amateur bands have frequencies authorized for space stations?

Select	Answer
A	Only the 40, 20, 17, 15, and 10 meter bands
B	Only the 40, 30, 20, 15, 12, and 10 meter bands
C	Only the 40, 20, 17, 15, 12, and 10 meter bands
D	All HF bands

6. - E1E12

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

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

7. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must exhibit a gain of 0 dB or less over its full output range
B	It must produce full legal output when driven by not more than 5 watts of mean RF input power
C	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
D	It must be capable of external RF switching between its input and output networks

8. - E2A02

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

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

9. - E2B04

How is color information sent in analog SSTV?

Select	Answer
A	Color lines are sent sequentially
B	Color information is sent on a 2.8 kHz subcarrier
C	Color is sent in a color burst at the end of each line
D	Color is amplitude modulated on the frequency modulated intensity signal

10. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of SSB or CW activity?

Select	Answer
A	In the weak signal segment of the band, with most of the activity near the calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the middle of the band, usually 25 kHz above the national calling frequency
D	In the middle of each band, usually on the national calling frequency

11. - E2D03

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

Select	Answer
A	PACTOR III
B	Olivia
C	JT65
D	MSK144

12. - E2E01

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

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

13. - E3A06

What might help to restore contact when DX signals become too weak to copy across an entire HF band a few hours after sunset?

Select	Answer
A	Switch to a lower frequency HF band
B	Wait 24 hours before attempting another communication on the band
C	Wait 90 minutes or so for the signal degradation to pass
D	Switch to a higher frequency HF band

14. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric refractions without an intermediate reflection from the ground
B	Propagation across the geomagnetic equator
C	Signals reflected back toward the transmitting station
D	Propagation away from the great circle bearing between stations

15. - E3C04

What does the value of Bz (B sub Z) represent?

Select	Answer
A	Geomagnetic field stability
B	Direction and strength of the interplanetary magnetic field
C	Critical frequency for vertical transmissions
D	Duration of long-delayed echoes

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	Amount of memory
C	Sampling rate of the analog-to-digital converter
D	All these choices are correct

17. - E4B05

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

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

18. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-174 dBm
B	-164 dBm
C	-148 dBm
D	-155 dBm

19. - E4D03

How can intermodulation interference between two repeaters occur?

Select	Answer
A	When the signals from the transmitters are reflected in phase from airplanes passing overhead
B	When the repeaters are in close proximity and the signals cause feedback in the final amplifier of one or both transmitters
C	When the signals from the transmitters are reflected out of phase from airplanes passing overhead
D	When the repeaters are in close proximity and the signals mix in the final amplifier of one or both transmitters

20. - E4E04

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

Select	Answer
A	By installing a noise suppression resistor and a blocking capacitor in both 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 connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads

21. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Reactance of the inductance multiplied by the reactance of the capacitance
B	Resistance divided by the reactance of either the inductance or capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

22. - E5B10

What is the relationship between the AC current through an inductor and the voltage across an inductor?

Select	Answer
A	Voltage and current are in phase
B	Current leads voltage by 90 degrees
C	Voltage and current are 180 degrees out of phase
D	Voltage leads current by 90 degrees

23. - E5C06

What does the impedance 50-j25 represent?

Select	Answer
A	25 ohms resistance in series with 50 ohms capacitive reactance
B	25 ohms resistance in series with 50 ohms inductive reactance
C	50 ohms resistance in series with 25 ohms capacitive reactance
D	50 ohms resistance in series with 25 ohms inductive reactance

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	0.866
B	0.5
C	1.73
D	1.414

25. - E6A11

In Figure E6-1, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	1
B	6
C	3
D	2

26. - E6B01

What is the most useful characteristic of a Zener diode?

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

27. - E6C11

In Figure E6-3, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	4
B	6
C	2
D	5

28. - E6D07

What is current in the primary winding of a transformer called if no load is attached to the secondary?

Select	Answer
A	Stabilizing current
B	Magnetizing current
C	Direct current
D	Excitation current

29. - E6E11

What is a characteristic of DIP packaging used for integrated circuits?

Select	Answer
A	Package mounts in a direct inverted position
B	Low leakage doubly insulated package
C	A total of two rows of connecting pins placed on opposite sides of the package (Dual In-line Package)
D	Two chips in each package (Dual In Package)

30. - E6F08

Why are optoisolators often used in conjunction with solid-state circuits when switching 120 VAC?

Select	Answer
A	Optoisolators eliminate the effects of reflected light in the control circuit
B	Optoisolators provide impedance matching between the control circuit and power circuit
C	Optoisolators provide a low impedance link between a control circuit and a power circuit
D	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Reverse Logic
B	Negative logic
C	Positive Logic
D	Assertive Logic

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

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	The Q of Pi-networks can be controlled
B	L-networks cannot perform impedance transformation
C	Pi-networks provide balanced input and output
D	Pi-networks are more stable

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 negative feedback to improve regulation
C	It provides D1 with current
D	It provides a constant load for the voltage source

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	The square root of the product of input frequencies
C	The two input frequencies along with their sum and difference frequencies
D	Two and four times the original frequency

36. - E7F03

What type of digital signal processing filter is used to generate an SSB signal?

Select	Answer
A	A Hilbert-transform filter
B	An elliptical filter
C	An adaptive filter
D	A notch filter

37. - E7G01

What is the typical output impedance of an op-amp?

Select	Answer
A	Very low
B	100 ohms
C	1000 ohms
D	Very high

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

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

39. - E8A05

What of the following instruments would be the most accurate for measuring the RMS voltage of a complex waveform?

Select	Answer
A	A grid dip meter
B	A D'Arsonval meter
C	A true-RMS calculating meter
D	An absorption wave meter

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	Extremely low-power contacts
C	EME
D	High-speed digital modes

41. - E8C07

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

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

42. - E8D02

What spread spectrum communications technique uses a high-speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Frequency hopping
B	Direct sequence
C	Binary phase-shift keying
D	Phase compandored spread spectrum

43. - E9A04

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

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

44. - E9B10

What is the principle of a Method of Moments analysis?

Select	Answer
A	A wire is modeled as a single sine-wave current generator
B	A wire is modeled as a series of segments, each having a distinct value of voltage across it
C	A wire is modeled as a single sine-wave voltage source
D	A wire is modeled as a series of segments, each having a uniform value of current

45. - E9C12

Which of the following describes an Extended Double Zepp antenna?

Select	Answer
A	An end-fed folded dipole antenna
B	A wideband vertical antenna constructed from precisely tapered aluminum tubing
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. - E9D09

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

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

47. - E9E08

What is a use for a Wilkinson divider?

Select	Answer
A	It is used to feed high-impedance antennas from a low-impedance source
B	It is used to divide power equally between two 50-ohm loads while maintaining 50-ohm input impedance
C	It divides the operating frequency of a transmitter signal so it can be used on a lower frequency band
D	It is used to feed low-impedance loads from a high-impedance source

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	13.3 meters
C	8.5 meters
D	10.6 meters

49. - E9G10

What do the arcs on a Smith chart represent?

Select	Answer
A	Points with constant reactance
B	Points with constant resistance
C	SWR
D	Frequency

50. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It increases the sensitivity of a DF antenna array
B	It allows DF antennas to receive signals at different vertical angles
C	It modifies the pattern of a DF antenna array to provide a null in one direction
D	It provides diversity reception that cancels multipath signals

Figure E6-1

Figure E6-3

Figure E7-2