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	300 Hz below the upper band edge
B	1 kHz below the upper band edge
C	3 kHz below the upper band edge
D	The exact 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
C	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference
D	The amateur station must cease operation on all frequencies below 30 MHz

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Messages intended for connection to users of the maritime satellite service
B	Business-related messages for non-profit organizations
C	Communications incidental to the purpose of the amateur service and remarks of a personal nature
D	All of these choices are correct

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of General, Advanced or Amateur Extra Class operators
B	Only those of Amateur Extra Class operators
C	Any amateur station, subject to the privileges of the class of operator license held by the control operator
D	Any amateur station whose licensee has filed a pre-space notification with the FCC's International Bureau

5. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the FCC according to instructions
B	They must collect and send the documents to the NCVEC for grading
C	They must collect and submit the documents to the coordinating VEC for grading
D	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	440 MHz - 450 MHz
B	53 MHz - 54 MHz
C	420 MHz - 430 MHz
D	222 MHz - 223 MHz

7. - E2A03

What is the orbital period of an Earth satellite?

Select	Answer
A	The time it takes for a satellite to complete one revolution around the Earth
B	The point of minimum height of a satellite's orbit
C	The time it takes for a satellite to travel from perigee to apogee
D	The point of maximum height of a satellite's orbit

8. - E2B04

What is blanking in a video signal?

Select	Answer
A	Turning off the scanning beam at the conclusion of a transmission
B	Synchronization of the horizontal and vertical sync pulses
C	Transmitting a black and white test pattern
D	Turning off the scanning beam while it is traveling from right to left or from bottom to top

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the weak signal segment of the band, with most of the activity near the calling frequency
B	In the middle of the band, usually 25 kHz above the national calling frequency
C	In the middle of each band, usually on the national calling frequency
D	At the top of each band, usually in a segment reserved for contests

10. - E2D08

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

Select	Answer
A	Unnumbered Information
B	Disconnect
C	Acknowledgement
D	Connect

11. - E2E09

Which of the following HF digital modes uses variable-length coding for bandwidth efficiency?

Select	Answer
A	RTTY
B	MT63
C	PACTOR
D	PSK31

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the Moon is at perigee
B	When the Moon is full
C	When the Moon is at apogee
D	When the MUF is above 30 MHz

13. - E3B08

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

Select	Answer
A	Transequatorial
B	Long-path
C	Sporadic-E
D	Gray-line

14. - E3C08

What does the space weather term G5 mean?

Select	Answer
A	Waning sunspot numbers
B	Moderate solar wind
C	Very low solar activity
D	An extreme geomagnetic storm

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

16. - E4B06

How much power is being absorbed by the load when a directional power meter connected between a transmitter and a terminating load reads 100 watts forward power and 25 watts reflected power?

Select	Answer
A	100 watts
B	75 watts
C	125 watts
D	25 watts

17. - E4C05

What does a value of -174 dBm/Hz represent with regard to the noise floor of a receiver?

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

18. - E4D13

Which of the following can cause receiver desensitization?

Select	Answer
A	Strong adjacent channel signals
B	Audio bias adjusted too high
C	Audio gain adjusted too low
D	Squelch gain misadjusted

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	A defective doorbell or doorbell transformer inside a nearby residence
B	A malfunctioning illuminated advertising display
C	Arcing contacts in a thermostatically controlled device
D	All of these choices are correct

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	23.5 kHz
B	7.12 MHz
C	7.12 kHz
D	23.5 MHz

21. - E5B06

What is susceptance?

Select	Answer
A	The inverse of reactance
B	A measure of the efficiency of a transformer
C	The ratio of magnetic field to electric field
D	The magnetic impedance of a circuit

22. - E5C02

How are impedances described in polar coordinates?

Select	Answer
A	By phase angle and amplitude
B	By real and imaginary parts
C	By Y and G values
D	By X and R values

23. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor decrease the impedance
B	Thermal effects on the surface of the conductor increase the impedance
C	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface
D	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	N-type
B	Insulated gate
C	P-type
D	Bipolar

25. - E6B10

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

Select	Answer
A	1
B	5
C	6
D	7

26. - E6C04

What is the primary advantage of tri-state logic?

Select	Answer
A	More efficient arithmetic operations
B	Ability to connect many device outputs to a common bus
C	High speed operation
D	Low power consumption

27. - E6D05

What is one reason for using ferrite cores rather than powdered-iron in an inductor?

Select	Answer
A	Ferrite toroids are easier to use with surface mount technology
B	Ferrite toroids generally have better temperature stability
C	Ferrite toroids generally have lower initial permeability
D	Ferrite toroids generally require fewer turns to produce a given inductance value

28. - E6E03

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

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

29. - E6F08

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

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 a low impedance link between a control circuit and a power circuit
D	Optoisolators provide impedance matching between the control circuit and power circuit

30. - E7A02

What is the function of a decade counter digital IC?

Select	Answer
A	It produces one output pulse for every ten input pulses
B	It adds two decimal numbers together
C	It decodes a decimal number for display on a seven segment LED display
D	It produces ten output pulses for every input pulse

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Select transistors with high beta
B	All of these choices are correct
C	Use a resistor in series with the emitter
D	Neutralization

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter
B	A variable bandwidth crystal lattice filter
C	An automatic notch filter
D	A special filter that emphasizes image responses

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

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

34. - E7E03

How does an analog phase modulator function?

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

35. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Sample width in bits
B	Sample rate
C	Processor latency
D	Sample clock phase noise

36. - E7G01

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

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

37. - E7H14

What is a phase-locked loop circuit?

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

38. - E8A13

Which of these methods is commonly used to convert analog signals to digital signals?

Select	Answer
A	Harmonic regeneration
B	Sequential sampling
C	Level shifting
D	Phase reversal

39. - E8B11

What is digital time division multiplexing?

Select	Answer
A	Two or more data streams are assigned to discrete sub-carriers on an FM transmitter
B	Two or more data streams share the same channel by transmitting time of transmission as the sub-carrier
C	Two or more signals are quadrature modulated to increase bandwidth efficiency
D	Two or more signals are arranged to share discrete time slots of a data transmission

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 13 Hz
B	Approximately 104 Hz
C	Approximately 52 Hz
D	Approximately 26 Hz

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	+10 dB
B	-20 dB
C	+15 dB
D	-30 dB

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The final amplifier gain minus the transmission line losses
B	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
C	The ratio of the signal in the forward direction to that in the opposite direction
D	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna

43. - E9B01

In the antenna radiation pattern shown in Figure E9-1, what is the 3 dB beam-width?

Select	Answer
A	25 degrees
B	50 degrees
C	75 degrees
D	30 degrees

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The main lobe takeoff angle decreases with increasing height
B	The main lobe takeoff angle increases with increasing height
C	The horizontal beam width decreases with height
D	The horizontal beam width increases with height

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	Near the center of the vertical radiator
C	At a voltage node
D	As low as possible on the vertical radiator

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	Use the universal stub matching technique
C	Connect a parallel-resonant LC network across the antenna feed terminals
D	Connect a series-resonant LC network across the antenna feed terminals

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.10
B	0.30
C	2.70
D	0.66

48. - E9G03

Which of the following is often determined using a Smith chart?

Select	Answer
A	Satellite azimuth and elevation bearings
B	Beam headings and radiation patterns
C	Trigonometric functions
D	Impedance and SWR values in transmission lines

49. - E9H07

Why is it advisable to use an RF attenuator on a receiver being used for direction finding?

Select	Answer
A	It reduces loss of received signals caused by antenna pattern nulls, thereby increasing sensitivity
B	It compensates for the effects of an isotropic antenna, thereby improving directivity
C	It prevents receiver overload which could make it difficult to determine peaks or nulls
D	It narrows the bandwidth of the received signal to improve signal to noise ratio

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Advise your neighbors of the results of your tests
B	Make sure signals from your station are less than the controlled MPE limits
C	Make sure signals from your station are less than the uncontrolled MPE limits
D	You need only evaluate exposure levels on your own property

Figure E6-3

Figure E9-1