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

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1. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	Ground reflections and scattering make the field strength vary with location
B	E field and H field radiation intensity peaks can occur at different locations
C	All these choices are correct
D	The body reacts to electromagnetic radiation from both the E and H fields

2. - E1A09

What action or actions should you take if your digital message forwarding station inadvertently forwards a communication that violates FCC rules?

Select	Answer
A	All these choices are correct
B	Discontinue forwarding the communication as soon as you become aware of it
C	Notify the nearest FCC Field Engineers office
D	Notify the originating station that the communication does not comply with FCC rules

3. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Military Auxiliary Radio System (MARS) channels
B	All amateur service frequencies authorized to the control operator
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	Specific local government channels

4. - E1C08

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

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

5. - E1D03

What is a space telecommand station?

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

6. - E1E01

For which types of out-of-pocket expenses do the Part 97 rules state that VEs and VECs may be reimbursed?

Select	Answer
A	Teaching an amateur operator license examination preparation course
B	No expenses are authorized for reimbursement
C	Providing amateur operator license examination preparation training materials
D	Preparing, processing, administering, and coordinating an examination for an amateur radio operator license

7. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the government of Canada?

Select	Answer
A	Full privileges, up to and including those of the Amateur Extra Class license, on the 80, 40, 20, 15, and 10 meter bands
B	All privileges of the Amateur Extra Class license
C	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Amateur Extra Class license privileges
D	None, they must obtain a U.S. license

8. - E2A05

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

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

9. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	A type of modulation in which one sideband is inverted
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
D	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

10. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send your full call sign once or twice
B	Send the call sign of the DX station three times, the words this is,then your call sign three times
C	Send your full call sign and grid square
D	Send only the last two letters of your call sign until you make contact

11. - E2D08

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

Select	Answer
A	Unnumbered Information
B	Connect
C	Acknowledgement
D	Disconnect

12. - E2E06

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

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

13. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Forests
B	Urban areas
C	Mountain ranges
D	Bodies of water

14. - E3B04

What is meant by the terms "extraordinary" and "ordinary" waves?

Select	Answer
A	Refracted rays and reflected waves
B	Long-path and short-path waves
C	Independent waves created in the ionosphere that are elliptically polarized
D	Extraordinary waves describe rare long-skip propagation compared to ordinary waves, which travel shorter distances

15. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 50 percent of the distance
B	By approximately four times the distance
C	By approximately twice the distance
D	By approximately 15 percent of the distance

16. - E4A09

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	Never use a high-impedance probe to measure a low-impedance circuit
B	All these choices are correct
C	Keep the signal ground connection of the probe as short as possible
D	Never use a DC-coupled probe to measure an AC circuit

17. - E4B04

Which S parameter represents input port return loss or reflection coefficient (equivalent to VSWR)?

Select	Answer
A	S22
B	S21
C	S12
D	S11

18. - E4C05

What does a receiver noise floor of -174 dBm represent?

Select	Answer
A	The theoretical noise in a 1 Hz bandwidth at the input of a perfect receiver at room temperature
B	The noise figure of a 1 Hz bandwidth receiver
C	The galactic noise contribution to minimum detectable signal
D	The minimum detectable signal as a function of receive frequency

19. - E4D03

How can intermodulation interference between two repeaters occur?

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

20. - E4E08

What current flows equally on all conductors of an unshielded multi-conductor cable?

Select	Answer
A	Reactive current only
B	Differential-mode current
C	Common-mode current
D	Return current

21. - E5A15

Which of the following increases Q for inductors and capacitors?

Select	Answer
A	Lower self-resonant frequency
B	Higher self-resonant frequency
C	Lower losses
D	Lower reactance

22. - E5B01

What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the applied voltage or to discharge to 36.8% of its initial voltage?

Select	Answer
A	A time factor of one
B	An exponential rate of one
C	One time constant
D	One exponential period

23. - E5C07

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

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

24. - E5D08

How many watts are consumed in a circuit having a power factor of 0.6 if the input is 200VAC at 5 amperes?

Select	Answer
A	200 watts
B	600 watts
C	1000 watts
D	1600 watts

25. - E6A01

In what application is gallium arsenide used as a semiconductor material?

Select	Answer
A	In microwave circuits
B	In very low-frequency RF circuits
C	In high-power audio circuits
D	In high-current rectifier circuits

26. - E6B03

What type of bias is required for an LED to emit light?

Select	Answer
A	Reverse bias
B	Forward bias
C	Zero bias
D	Inductive bias

27. - E6C09

What is a Programmable Logic Device (PLD)?

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

28. - E6D12

What is inductor saturation?

Select	Answer
A	The inductor's voltage rating is exceeded causing a flashover
B	Adjacent inductors become over-coupled
C	The inductor windings are over-coupled
D	The ability of the inductor's core to store magnetic energy has been exceeded

29. - E6E06

What characteristics of the MMIC make it a popular choice for VHF through microwave circuits?

Select	Answer
A	The ability to retrieve information from a single signal even in the presence of other strong signals
B	Controlled gain, low noise figure, and constant input and output impedance over the specified frequency range
C	Plate current that is controlled by a control grid
D	Nearly infinite gain, very high input impedance, and very low output impedance

30. - E6F06

Which of these materials is most commonly used to create photoconductive devices?

Select	Answer
A	An ordinary metal
B	A crystalline semiconductor
C	A heavy metal
D	A liquid semiconductor

31. - E7A09

What logical operation is performed by an exclusive NOR gate?

Select	Answer
A	It produces logic 0 at its output if only one input is logic 1
B	It produces logic 1 at its output only if all inputs are logic 1
C	It produces logic 1 at its output if only one input is logic 1
D	It produces logic 0 at its output only if all inputs are logic 0

32. - E7B06

Which of the following amplifier types reduces even-order harmonics?

Select	Answer
A	Class AB
B	Push-push
C	Class C
D	Push-pull

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Extremely flat response over its pass band with gradually rounded stop band corners
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely sharp cutoff with one or more notches in the stop band
D	Gradual passband rolloff with minimal stop band ripple

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To provide a dual-voltage output for reduced power applications
B	To compensate for variations of the incoming line voltage
C	To allow the filter capacitors to charge gradually
D	To allow for remote control of the power supply

35. - E7E08

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

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

36. - E7F14

Which of the following would allow a digital signal processing filter to create a sharper filter response?

Select	Answer
A	More taps
B	Double-precision math routines
C	Complex phasor representations
D	Higher data rate

37. - E7G04

What is meant by the "op-amp input offset voltage"?

Select	Answer
A	The differential input voltage needed to bring the open loop output voltage to zero
B	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
C	The output voltage of the op-amp minus its input voltage
D	The potential between the amplifier input terminals of the op-amp in an open loop condition

38. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic circuit consisting of a precision push-pull amplifier with a differential input
C	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
D	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator

39. - E8A11

Which of the following is a measure of the quality of an analog-to-digital converter?

Select	Answer
A	Peak envelope power
B	Reciprocal mixing
C	Power factor
D	Total harmonic distortion

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	High-speed digital modes
B	OFDM signals are not allowed on amateur bands
C	EME
D	Extremely low-power contacts

41. - E8C10

How may data rate be increased without increasing bandwidth?

Select	Answer
A	Increasing analog-to-digital conversion resolution
B	It is impossible
C	Using a more efficient digital code
D	Using forward error correction

42. - E8D05

What is the most common method of reducing key clicks?

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

43. - E9A04

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

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

44. - E9B10

What is the principle of a Method of Moments analysis?

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

45. - E9C10

Which of the following describes a Zepp antenna?

Select	Answer
A	A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
B	An omni-directional antenna commonly used for satellite communications
C	An end-fed dipole antenna
D	A dipole constructed from zip cord

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

47. - E9E11

What is the primary purpose of phasing lines when used with an antenna having multiple driven elements?

Select	Answer
A	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
B	It allows single-band antennas to operate on other bands
C	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
D	It creates a low-angle radiation pattern

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Lower loss
B	Smaller reflection coefficient
C	Higher SWR
D	Lower velocity factor

49. - E9G11

How are the wavelength scales on a Smith chart calibrated?

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

50. - E9H05

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

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