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. - 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 are ionizing radiation
C	The high gain antennas commonly used can result in high exposure levels
D	Microwaves often travel long distances by ionospheric reflection

2. - E1A01

Which of the following carrier frequencies is illegal for LSB AFSK emissions on the 17 meter band RTTY and data segment of 18.068 to 18.110 MHz?

Select	Answer
A	18.068 MHz
B	18.100 MHz
C	18.107 MHz
D	18.110 MHz

3. - E1B07

To what type of regulations does PRB-1 apply?

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

4. - E1C08

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

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

5. - E1D03

What is a space telecommand station?

Select	Answer
A	An amateur station located on the surface of the Earth for communication with other Earth stations by means of Earth satellites
B	An amateur station that receives telemetry from a satellite or balloon more than 50 kilometers above the surface of the Earth
C	An amateur station that transmits communications to initiate, modify or terminate functions of a space station
D	An amateur station located in a satellite or a balloon more than 50 kilometers above the surface of the Earth

6. - E1E12

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

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

7. - E1F01

On what frequencies are spread spectrum transmissions permitted?

Select	Answer
A	Only on amateur frequencies above 420 MHz
B	Only on amateur frequencies above 144 MHz
C	Only on amateur frequencies above 50 MHz
D	Only on amateur frequencies above 222 MHz

8. - E2A05

What do the letters in a satellite's mode designator specify?

Select	Answer
A	The polarization of uplink and downlink signals
B	The location of the ground control station
C	The uplink and downlink frequency ranges
D	Power limits for uplink and downlink transmissions

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 frequencies
D	Specific tone amplitudes

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	/ followed by the USPS two-letter abbreviation for the state in which the remote station is located
B	/ followed by the ARRL Section of the remote station
C	/R# where # is the district of the remote station
D	No additional indicator is required

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. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Final Error Correction
B	Forward Error Correction
C	First Error Correction
D	Fatal Error Correction

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 F2 layer between the solar wind and the Van Allen belt
D	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field

14. - E3B03

What is the best time of day for transequatorial propagation?

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

15. - E3C01

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

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

16. - E4A02

Which of the following parameters does a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and time
B	SWR and frequency
C	RF amplitude and time
D	RF amplitude and frequency

17. - E4B03

Which S parameter is equivalent to forward gain?

Select	Answer
A	S11
B	S21
C	S22
D	S12

18. - E4C12

Which of the following has the largest effect on an SDR receiver's dynamic range?

Select	Answer
A	Analog-to-digital converter sample width in bits
B	Anti-aliasing input filter bandwidth
C	RAM speed used for data storage
D	CPU register width in bits

19. - E4D08

What causes intermodulation in an electronic circuit?

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

20. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals that are constant at all IF levels
B	Signals that have a sharply peaked frequency distribution
C	Signals that appear across a wide bandwidth
D	Signals that appear at one IF but not another

21. - E5A10

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

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

22. - E5B09

What is the relationship between the AC current through a capacitor and the voltage across a capacitor?

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

23. - E5C04

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

Select	Answer
A	Rectangular coordinates
B	Elliptical coordinates
C	Maidenhead grid
D	Faraday grid

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

25. - E6A08

What term indicates the frequency at which the grounded-base current gain of a transistor has decreased to 0.7 of the gain obtainable at 1 kHz?

Select	Answer
A	Corner frequency
B	Alpha rejection frequency
C	Beta cutoff frequency
D	Alpha cutoff frequency

26. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	More constant reverse avalanche voltage
B	Less forward voltage drop
C	Much higher reverse voltage breakdown
D	Longer carrier retention time

27. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor in a keying circuit used to reduce key clicks
B	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit
C	A resistor connected to an op-amp output that prevents signals from exceeding the power supply voltage
D	A resistor that ensures that an oscillator frequency does not drift

28. - E6D01

Why should core saturation of an impedance matching transformer be avoided?

Select	Answer
A	Harmonics and distortion could result
B	Temporary changes of the core permeability could result
C	RF susceptance would increase
D	Magnetic flux would increase with frequency

29. - E6E11

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

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

30. - E6F08

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

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

31. - E7A04

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

Select	Answer
A	1
B	2
C	8
D	4

32. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune both the input and output for maximum power
B	Tune the stage for maximum SWR
C	Use a phase inverter in the output filter
D	Install parasitic suppressors and/or neutralize the stage

33. - E7C07

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50-ohm unbalanced output?

Select	Answer
A	A Pi-network with an additional series inductor on the output
B	A Phase Inverter Load network
C	A matching network in which all components are isolated from ground
D	A network with only three discrete parts

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

35. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable resistance
B	To produce PM or FM signals by using an electrically variable inductance or capacitance
C	To produce AM signals by using an electrically variable inductance or capacitance
D	To produce AM signals by using an electrically variable resistance

36. - E7F07

What function is performed by a Fast Fourier Transform?

Select	Answer
A	Converting digital signals to analog form
B	Converting digital signals from the time domain to the frequency domain
C	Converting 8-bit data to 16-bit data
D	Converting analog signals to digital form

37. - E7G01

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

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

38. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Digital conversion noise
B	Broadband noise
C	Spurious signals at discrete frequencies
D	Nyquist limit noise

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	The frequency of the modulating signal
B	Amplifier gain
C	Speech characteristics
D	The degree of carrier suppression

40. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency?

Select	Answer
A	It decreases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It increases as the RF carrier frequency increases
D	It varies with the square root of the RF carrier frequency

41. - E8C02

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

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

42. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The receiver is always equipped with a digital blanker
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

43. - E9A05

What is included in the total resistance of an antenna system?

Select	Answer
A	Transmission-line resistance plus radiation resistance
B	Radiation resistance plus transmission resistance
C	Radiation resistance plus loss resistance
D	Radiation resistance plus space impedance

44. - E9B08

What is the far field of an antenna?

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

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 folded dipole center-fed with 300-ohm transmission line
D	A dipole fed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation

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	62 ohms
C	50 ohms
D	450 ohms

48. - E9F02

Which of the following has the biggest effect on the velocity factor of a transmission line?

Select	Answer
A	Dielectric materials used in the line
B	The line length
C	The termination impedance
D	The center conductor resistivity

49. - E9G10

What do the arcs on a Smith chart represent?

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

50. - E9H05

What is the main drawback of a small wire-loop antenna for direction finding?

Select	Answer
A	It is practical for use only on VHF and higher bands
B	All these choices are correct
C	It has no clearly defined null
D	It has a bidirectional pattern

Figure E7-2