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

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1. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Only commercial transmitters
B	Only the most powerful transmitter
C	Each transmitter that produces 5 percent or more of its MPE limit in areas where the total MPE limit is exceeded.
D	Each transmitter operating with a duty cycle greater than 50 percent

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

3. - E1B09

Which amateur stations may be operated under RACES rules?

Select	Answer
A	Any FCC-licensed amateur station except a Technician Class
B	Only those club stations licensed to Amateur Extra Class operators
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. - E1C12

On what portion of the 630 meter band are phone emissions permitted?

Select	Answer
A	Only the top 3 kHz
B	None
C	The entire band
D	Only the bottom 3 kHz

5. - E1D08

Which VHF amateur bands have frequencies authorized for space stations?

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

6. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Issue the examinee the new or upgrade license
B	All these choices are correct
C	Photocopy all examination documents and forward them to the FCC for processing
D	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

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 neither the amateur nor his or her employer has a pecuniary interest in the communications
C	When the control operator is employed by the FCC or another government agency
D	When transmitting international third-party communications

8. - E2A10

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

Select	Answer
A	HEO
B	Geostationary
C	LEO
D	Geomagnetic

9. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Spectral intensity
C	Luminance
D	Hue

10. - E2C07

What is the Cabrillo format?

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

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
B	All these choices are correct
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event

12. - E2E06

What is the most common data rate used for HF packet?

Select	Answer
A	48 baud
B	110 baud
C	300 baud
D	1200 baud

13. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Wind shear
B	Dust devil
C	Temperature inversion
D	The jet stream

14. - E3B09

At what time of year is sporadic E propagation most likely to occur?

Select	Answer
A	Around the solstices, especially the winter solstice
B	Around the equinoxes, especially the fall equinox
C	Around the solstices, especially the summer solstice
D	Around the equinoxes, especially the spring equinox

15. - E3C01

What does the radio communication term "ray tracing" describe?

Select	Answer
A	Modeling a radio wave's path through the ionosphere
B	Determining the radiation pattern from an array of antennas
C	Evaluating high voltage sources for x-rays
D	The process in which an electronic display presents a pattern

16. - E4A01

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

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

17. - E4B01

Which of the following factors most affects the accuracy of a frequency counter?

Select	Answer
A	Input attenuator accuracy
B	Time base accuracy
C	Decade divider accuracy
D	Temperature coefficient of the logic

18. - E4C04

What is the noise figure of a receiver?

Select	Answer
A	The ratio of atmospheric noise to phase noise
B	The ratio of thermal noise to atmospheric noise
C	The ratio in dB of the noise generated by the receiver to the theoretical minimum noise
D	The ratio of the noise bandwidth in hertz to the theoretical bandwidth of a resistive network

19. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To provide a range of AGC time constants
B	To allow selection of the optimum RF amplifier device
C	To increase rejection of signals outside the desired band
D	To store often-used frequencies

20. - E4E09

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

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

21. - E5A09

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

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

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	55 seconds
B	110 seconds
C	440 seconds
D	220 seconds

23. - E5C07

Where is the impedance of a pure resistance plotted on rectangular coordinates?

Select	Answer
A	On the vertical axis
B	On a line through the origin, slanted at 45 degrees
C	On a horizontal line, offset vertically above the horizontal axis
D	On the horizontal axis

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To increase neutralizing resistance
B	To reduce phase shift along the connection
C	To reduce noise figure
D	To increase compensating capacitance

25. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 6 to 7 ohms
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

26. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch?

Select	Answer
A	Extremely high reverse breakdown voltage
B	Ability to dissipate large amounts of power
C	Reverse bias controls its forward voltage drop
D	Low junction capacitance

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. - 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	Excitation current
C	Magnetizing current
D	Direct current

29. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	SOT
B	PLCC
C	Ball grid array
D	DIP

30. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An LED and a phototransistor
C	A lens and a photomultiplier
D	An amplitude modulated helium-neon laser

31. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	1
B	4
C	8
D	2

32. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Emitter follower
B	Common base
C	Common emitter
D	Common collector

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

34. - E7D08

What type of circuit is shown in Figure E7-2?

Select	Answer
A	Monostable multivibrator
B	Linear voltage regulator
C	Grounded emitter amplifier
D	Switching voltage regulator

35. - E7E08

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

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

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 four times 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 least half the rate of the highest frequency component of the signal

37. - E7G05

How can unwanted ringing and audio instability be prevented in an op-amp RC audio filter circuit?

Select	Answer
A	Increase both gain and Q
B	Restrict gain but increase Q
C	Restrict Q but increase gain
D	Restrict both gain and Q

38. - E7H08

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

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

39. - E8A08

Why would a direct or flash conversion analog-to-digital converter be useful for a software defined radio?

Select	Answer
A	Immunity to out-of-sequence coding reduces spurious responses
B	Very high speed allows digitizing high frequencies
C	All these choices are correct
D	Very low power consumption decreases frequency drift

40. - E8B09

What is deviation ratio?

Select	Answer
A	The ratio of the highest audio modulating frequency to the average audio modulating frequency
B	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency
C	The ratio of the carrier center frequency to the audio modulating frequency
D	The ratio of the audio modulating frequency to the center carrier frequency

41. - E8C04

What technique minimizes the bandwidth of a PSK31 signal?

Select	Answer
A	Zero-sum character encoding
B	Reed-Solomon character encoding
C	Use of trapezoidal data pulses
D	Use of sinusoidal data pulses

42. - E8D05

What is the most common method of reducing key clicks?

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

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. - E9B05

What type of antenna pattern is shown in Figure E9-2?

Select	Answer
A	Elevation
B	Radiation resistance
C	Azimuth
D	Polarization

45. - E9C05

Which of the following is a type of OCFD antenna?

Select	Answer
A	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
B	A folded dipole center-fed with 300-ohm transmission line
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation

46. - E9D05

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The frequency response is widened over the whole frequency band
C	The front-to-back ratio increases
D	The front-to-back ratio decreases

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

48. - E9F12

What impedance does a 1/4-wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	Very high impedance
B	Very low impedance
C	The same as the characteristic impedance of the line
D	The same as the input impedance to the generator

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	Atmospheric noise is so high that gain over a dipole is not important
B	Low loss coax transmission line is essential for good performance
C	They must be erected at least 1/2 wavelength above the ground to attain good directivity
D	All these choices are correct

Figure E7-1

Figure E7-2

Figure E9-2