US Amateur Radio - Amateur Extra (Element 4, 2016-2020) Practice Test

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1. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	1 kHz below the upper band edge
B	The exact upper band edge
C	300 Hz below the upper band edge
D	3 kHz below the upper band edge

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation on all frequencies above 30 MHz
B	The amateur station must cease operation on all frequencies below 30 MHz
C	The amateur station must cease operation
D	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference

3. - E1C02

What is meant by automatic control of a station?

Select	Answer
A	A station operating with its output power controlled automatically
B	The use of devices and procedures for control so that the control operator does not have to be present at a control point
C	The use of a control link between a control point and a locally controlled station
D	Remotely controlling a station's antenna pattern through a directional control link

4. - E1D03

What is a telecommand station in the amateur satellite service?

Select	Answer
A	An amateur station that transmits telemetry consisting of measurements of upper atmosphere
B	An amateur station located more than 50 km above the Earth's surface
C	An amateur station located on the Earth's surface for communication with other Earth stations by means of Earth satellites
D	An amateur station that transmits communications to initiate, modify or terminate functions of a space station

5. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The prospective VE obtains accreditation from the FCC
B	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
C	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
D	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau

6. - E1F12

Who may be the control operator of an auxiliary station?

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

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	All of these choices are correct
B	FM and CW
C	PSK and Packet
D	SSB and SSTV

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	Frequency modulation of the video carrier
B	All of these choices are correct
C	A separate VHF or UHF audio link
D	Frequency-modulated sub-carrier

9. - E2C05

What is the function of a DX QSL Manager?

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

10. - E2D08

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

Select	Answer
A	Connect
B	Unnumbered Information
C	Acknowledgement
D	Disconnect

11. - E2E04

What is indicated when one of the ellipses in an FSK crossed-ellipse display suddenly disappears?

Select	Answer
A	One of the signal filters is saturated
B	Selective fading has occurred
C	The receiver has drifted 5 kHz from the desired receive frequency
D	The mark and space signal have been inverted

12. - E3A16

Which of the following best describes electromagnetic waves traveling in free space?

Select	Answer
A	The energy propagates through a medium with a high refractive index
B	The waves are reflected by the ionosphere and return to their source
C	Changing electric and magnetic fields propagate the energy
D	Electric and magnetic fields become aligned as they travel

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	1000 miles
B	2500 miles
C	7500 miles
D	5000 miles

14. - E3C09

How does the intensity of an X3 flare compare to that of an X2 flare?

Select	Answer
A	10 percent greater
B	Twice as great
C	Four times as great
D	50 percent greater

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	It depends on how the data is stored internally
B	One-tenth the sample rate
C	One-half the sample rate
D	The same as the sample rate

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	0.1 MHz
B	1.4652 kHz
C	14.652 Hz
D	1.4652 Hz

17. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves dynamic range by attenuating strong signals near the receive frequency
B	It improves sensitivity by reducing front end noise
C	It improves intelligibility by using low Q circuitry to reduce ringing
D	All of these choices are correct

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
B	Cross-modulation of the desired signal and desensitization from strong adjacent signals
C	Oscillator instability and severe audio distortion of all but the strongest received signals
D	Cross-modulation of the desired signal and insufficient audio power to operate the speaker

19. - 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	Nearby signals may appear to be excessively wide even if they meet emission standards
D	Received audio in the speech range might have an echo effect

20. - E5A06

What is the magnitude of the circulating current within the components of a parallel LC circuit at resonance?

Select	Answer
A	It equals 2 multiplied by Pi, multiplied by frequency, multiplied by inductance
B	It is at a minimum
C	It equals 1 divided by the quantity 2 times Pi, multiplied by the square root of inductance L multiplied by capacitance C
D	It is at a maximum

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	76 degrees with the voltage lagging the current
B	14 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage leading the current

22. - E5C07

What is a vector?

Select	Answer
A	The inverse of the tangent function
B	The value of a quantity that changes over time
C	A quantity with both magnitude and an angular component
D	The inverse of the sine function

23. - 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 reactive power by the power factor
B	By multiplying the apparent power times the power factor
C	By dividing the apparent power by the power factor
D	By multiplying the reactive power times the power factor

24. - E6A16

What are the majority charge carriers in N-type semiconductor material?

Select	Answer
A	Free protons
B	Free neutrons
C	Holes
D	Free electrons

25. - E6B10

In Figure E6-3, what is the schematic symbol for a light-emitting diode?

Select	Answer
A	7
B	5
C	6
D	1

26. - 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	Programmable equipment used for testing digital logic integrated circuits
C	A device to control industrial equipment
D	An algorithm for simulating logic functions during circuit design

27. - E6D13

What is the primary cause of inductor self-resonance?

Select	Answer
A	Non-linear core hysteresis
B	The skin effect
C	Inter-turn capacitance
D	Inductive kickback

28. - E6E05

Which of the following noise figure values is typical of a low-noise UHF preamplifier?

Select	Answer
A	-10 dB
B	2 dB
C	-20 dBm
D	44 dBm

29. - E6F14

Which of the following is true of LCD displays?

Select	Answer
A	They may be hard view through polarized lenses
B	They only display alphanumeric symbols
C	All of these choices are correct
D	They are hard to view in high ambient light conditions

30. - E7A12

What type of logic defines "0" as a high voltage?

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

31. - 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	Signal inversion
B	Reduced intermodulation products
C	Increased overall intelligibility
D	Signal distortion and excessive bandwidth

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Greater harmonic suppression
B	Greater transformation range
C	Higher efficiency
D	Lower losses

33. - E7D02

What is one characteristic of a switching electronic voltage regulator?

Select	Answer
A	The resistance of a control element is varied in direct proportion to the line voltage or load current
B	It gives a ramp voltage at its output
C	It is generally less efficient than a linear regulator
D	The controlled device's duty cycle is changed to produce a constant average output voltage

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of an amplifier tank circuit to produce PM signals
B	By varying the tuning of a microphone preamplifier to produce AM signals
C	By varying the tuning of an amplifier tank circuit to produce AM signals
D	By varying the tuning of a microphone preamplifier to produce PM signals

35. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	A crystal-lattice filter
B	An adaptive filter
C	A Hilbert-transform filter
D	A phase-inverting filter

36. - E7G08

How does the gain of an ideal operational amplifier vary with frequency?

Select	Answer
A	It increases linearly with increasing frequency
B	It decreases logarithmically with increasing frequency
C	It decreases linearly with increasing frequency
D	It does not vary with frequency

37. - E7H15

Which of these functions can be performed by a phase-locked loop?

Select	Answer
A	Wide-band AF and RF power amplification
B	Comparison of two digital input signals, digital pulse counter
C	Photovoltaic conversion, optical coupling
D	Frequency synthesis, FM demodulation

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	A method of decimation by randomly skipping samples
B	An abnormal condition where the converter cannot settle on a value to represent the signal
C	An error caused by irregular quantization step size
D	A small amount of noise added to the input signal to allow more precise representation of a signal over time

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	The transmitted signal is divided into packets of information
B	The transmitted signal jumps from band to band at a predetermined rate
C	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
D	Two or more information streams are merged into a baseband, which then modulates the transmitter

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special binary codes provide automatic correction
B	If errors are detected, a retransmission is requested
C	Special polynomial codes provide automatic correction
D	If errors are detected, redundant data is substituted

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	Limits data speed
B	The generation of RF harmonics
C	More difficult to copy
D	The generation of key clicks

42. - E9A10

Which of the following choices is a way to improve the efficiency of a ground-mounted quarter-wave vertical antenna?

Select	Answer
A	Shorten the radiating element
B	Isolate the coax shield from ground
C	Reduce the diameter of the radiating element
D	Install a good radial system

43. - E9B03

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

Select	Answer
A	24 dB
B	14 dB
C	18 dB
D	12 dB

44. - E9C13

What is the main effect of placing a vertical antenna over an imperfect ground?

Select	Answer
A	It reduces losses in the radiating portion of the antenna
B	It causes increased SWR
C	It reduces low-angle radiation
D	It changes the impedance angle of the matching network

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

Select	Answer
A	It is too sharply directional at lower frequencies
B	It radiates the harmonics and fundamental equally well
C	It might radiate harmonics
D	It must be neutralized

46. - E9E11

What is an effective way of matching a feed line to a VHF or UHF antenna when the impedances of both the antenna and feed line are unknown?

Select	Answer
A	Use a 50 ohm 1:1 balun between the antenna and feed line
B	Connect a parallel-resonant LC network across the antenna feed terminals
C	Use the universal stub matching technique
D	Connect a series-resonant LC network across the antenna feed terminals

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

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

48. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Reactance and voltage
B	Voltage and impedance
C	Resistance and voltage
D	Resistance and reactance

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station uses three different antennas to plot the location of the signal source
B	Antenna headings from several different receiving locations are used to locate the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station plots three headings to the signal source

50. - E0A08

What does SAR measure?

Select	Answer
A	Synthetic Aperture Ratio of the human body
B	The rate of RF energy reflected from stationary terrain
C	Signal Amplification Rating
D	The rate at which RF energy is absorbed by the body

Figure E6-3

Figure E9-1