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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	Any ordinary smoke detector can be used
B	By the yellowish appearance of the gas
C	Only with a carbon monoxide detector
D	By the odor

2. - E1A12

What special operating frequency restrictions are imposed on slow scan TV transmissions?

Select	Answer
A	None; they are allowed on all amateur frequencies
B	They are restricted to 7.245 MHz, 14.245 MHz, 21.345 MHz, and 28.945 MHz
C	They are restricted to phone band segments
D	They are not permitted above 54 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C12

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

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

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	All HF bands
D	Only the 40, 20, 17, 15, 12, and 10 meter bands

6. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	Employees of the VE
B	Friends of the VE
C	Relatives of the VE as listed in the FCC rules
D	All these choices are correct

7. - E1F10

Who may be the control operator of an auxiliary station?

Select	Answer
A	Only Technician, General, Advanced or Amateur Extra Class operators
B	Only General, Advanced or Amateur Extra Class operators
C	Any licensed amateur operator
D	Only Amateur Extra Class operators

8. - E2A08

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

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

9. - E2B03

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

Select	Answer
A	By scanning lines from left to right in one field and right to left in the next
B	By scanning odd numbered lines in one field and even numbered lines in the next
C	By scanning two fields simultaneously
D	By scanning each field from bottom to top

10. - E2C05

What is the function of a DX QSL Manager?

Select	Answer
A	To run a net to allow many stations to contact a rare DX station
B	To handle the receiving and sending of confirmation cards for a DX station
C	To allocate frequencies for DXpeditions
D	To relay calls to and from a DX station

11. - E2D11

Which of the following data are used by the APRS network to communicate station location?

Select	Answer
A	Latitude and longitude
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Time and frequency

12. - E2E12

How do ALE stations establish contact?

Select	Answer
A	ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received
B	ALE radios activate when they hear their signal echoed by back scatter
C	ALE radios monitor an internet site for the frequency they are being paged on
D	ALE radios send a constant tone code to establish a frequency for future use

13. - E3A13

Which of these emission modes is best for auroral propagation?

Select	Answer
A	RTTY
B	CW
C	SSB
D	FM

14. - E3B10

Why is chordal hop propagation desirable?

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

15. - E3C01

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

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

16. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Network analyzer
B	Bit error rate tester
C	Modulation monitor
D	Logic analyzer

17. - E4B11

Which of the following can be measured with a vector network analyzer?

Select	Answer
A	Reflection coefficient
B	Output impedance
C	All these choices are correct
D	Input impedance

18. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a superheterodyne HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Reduced drift
C	Fewer components in the receiver
D	Easier for front-end circuitry to eliminate image responses

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E09

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

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

21. - E5A10

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

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance multiplied by the reactance of the 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 180 degrees out of phase
B	Current leads voltage by 90 degrees
C	Voltage and current are in phase
D	Voltage leads current by 90 degrees

23. - E5C09

When using rectangular coordinates to graph the impedance of a circuit, what do the axes represent?

Select	Answer
A	The X axis represents the magnitude and the Y axis represents the phase angle
B	The X axis represents the reactive component and the Y axis represents the resistive component
C	The X axis represents the resistive component and the Y axis represents the reactive component
D	The X axis represents the phase angle and the Y axis represents the magnitude

24. - E5D10

How can the true power be determined in an AC circuit where the voltage and current are out of phase?

Select	Answer
A	By multiplying the apparent power by the power factor
B	By dividing the reactive power by the power factor
C	By dividing the apparent power by the power factor
D	By multiplying the reactive power by the power factor

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

26. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Tunnel diode
B	Varactor diode
C	Silicon-controlled rectifier
D	Zener diode

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

28. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Mechanical deformation of material by the application of a magnetic field
B	Generation of electrical energy in the presence of light
C	Mechanical deformation of material by the application of a voltage
D	Increased conductivity in the presence of light

29. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Gallium nitride
D	Silicon dioxide

30. - E6F02

What happens to the conductivity of a photoconductive material when light shines on it?

Select	Answer
A	It becomes unstable
B	It stays the same
C	It increases
D	It decreases

31. - E7A10

What is a truth table?

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

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 inversion
C	Reduced intermodulation products
D	Signal distortion and excessive bandwidth

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

34. - E7D12

What is the dropout voltage of an analog voltage regulator?

Select	Answer
A	Maximum output voltage drops when the input voltage is varied over its specified range
B	Maximum that the output voltage may decrease at rated load
C	Minimum input voltage for rated power dissipation
D	Minimum input-to-output voltage required to maintain regulation

35. - E7E07

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

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

36. - E7F03

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

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

37. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E73 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	94
B	47
C	24
D	0.21

38. - E7H01

What are three oscillator circuits used in amateur radio equipment?

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

39. - E8A10

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

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

40. - E8B01

What is the modulation index of an FM signal?

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

41. - E8C02

What is the definition of symbol rate in a digital transmission?

Select	Answer
A	The number of characters carried per second by the station-to-station link
B	The rate at which the waveform changes to convey information
C	The number of control characters in a message packet
D	The duration of each bit in a message sent over the air

42. - E8D05

What is the most common method of reducing key clicks?

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

43. - E9A07

What is the effective isotropic radiated power of a repeater station with 200 watts transmitter power output, 2 dB feed line loss, 2.8 dB duplexer loss, 1.2 dB circulator loss, and 7 dBi antenna gain?

Select	Answer
A	632 watts
B	252 watts
C	63.2 watts
D	159 watts

44. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	36 dB
B	14 dB
C	24 dB
D	18 dB

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

46. - E9D06

What happens to the SWR bandwidth when one or more loading coils are used to resonate an electrically short antenna?

Select	Answer
A	It is increased
B	It is unchanged if the loading coil is located at the feed point
C	It is decreased
D	It is unchanged if the loading coil is located at a voltage maximum point

47. - E9E08

What is a use for a Wilkinson divider?

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

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

49. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage lines and current chords
B	Resistance circles and reactance arcs
C	Voltage circles and current arcs
D	Resistance lines and reactance chords

50. - E9H09

What is a Pennant antenna?

Select	Answer
A	A stealth antenna built to look like a flagpole
B	A four-element, high-gain vertical array invented by George Pennant
C	A form of rhombic antenna terminated in a variable capacitor to provide frequency diversity
D	A small, vertically oriented receiving antenna consisting of a triangular loop terminated in approximately 900 ohms

Figure E9-1