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

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1. - E1A06

Where must the carrier frequency of a CW signal be set to comply with FCC rules for 60 meter operation?

Select	Answer
A	On any frequency where the signal's sidebands are within the channel
B	At the lowest frequency of the channel
C	At the highest frequency of the channel
D	At the center frequency of the channel

2. - E1B06

Which of the following additional rules apply if you are installing an amateur station antenna at a site at or near a public use airport?

Select	Answer
A	You may have to notify the Federal Aviation Administration and register it with the FCC as required by Part 17 of FCC rules
B	You must file an Environmental Impact Statement with the EPA before construction begins
C	No special rules apply if your antenna structure will be less than 300 feet in height
D	You must obtain a construction permit from the airport zoning authority

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	29.500 MHz - 29.700 MHz
B	24.940 MHz - 24.990 MHz
C	18.110 MHz - 18.168 MHz
D	10.100 MHz - 10.150 MHz

4. - E1D10

Which amateur stations are eligible to be telecommand stations?

Select	Answer
A	Any amateur station so designated by the ITU
B	Any amateur station so designated by the space station licensee, subject to the privileges of the class of operator license held by the control operator
C	Any amateur station designated by NASA
D	All of these choices are correct

5. - E1E09

What may be the penalty for a VE who fraudulently administers or certifies an examination?

Select	Answer
A	Revocation of the VE's amateur station license grant and the suspension of the VE's amateur operator license grant
B	All of these choices are correct
C	A fine of up to $1000 per occurrence
D	A sentence of up to one year in prison

6. - E1F09

Which of the following conditions apply when transmitting spread spectrum emission?

Select	Answer
A	All of these choices are correct
B	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions
C	The transmitting station must be in an area regulated by the FCC or in a country that permits SS emissions
D	The transmission must not be used to obscure the meaning of any communication

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	435 MHz - 438 MHz
C	50.0 MHz - 50.2 MHz
D	144 MHz - 146 MHz

8. - E2B14

What aspect of an amateur slow-scan television signal encodes the brightness of the picture?

Select	Answer
A	Tone frequency
B	Tone amplitude
C	Sync frequency
D	Sync amplitude

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	A method of exchanging information during a contest QSO
B	The most common set of contest rules
C	A standard for submission of electronic contest logs
D	The rules of order for meetings between contest sponsors

10. - E2D07

What digital protocol is used by APRS?

Select	Answer
A	802.11
B	AMTOR
C	PACTOR
D	AX.25

11. - E2E09

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

Select	Answer
A	RTTY
B	PSK31
C	PACTOR
D	MT63

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	FM
B	CW
C	SSB
D	RTTY

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two stations at the same latitude
B	Propagation between two continents by way of ducts along the magnetic equator
C	Propagation between any two points located on the magnetic equator
D	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Long-path propagation is occurring
B	A solar flare has occurred
C	A meteor ping
D	Increased transequatorial propagation likely

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	All signals will have a DC offset
B	False signals are displayed
C	Calibration of the vertical scale is no longer valid
D	False triggering occurs

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	Harmonics are generated
B	Intermodulation distortion occurs
C	Cross modulation occurs
D	A less accurate reading results

17. - E4C10

Which of the following is a desirable amount of selectivity for an amateur RTTY HF receiver?

Select	Answer
A	100 Hz
B	6000 Hz
C	300 Hz
D	2400 Hz

18. - E4D06

What is the term for unwanted signals generated by the mixing of two or more signals?

Select	Answer
A	Amplifier desensitization
B	Intermodulation interference
C	Adjacent channel interference
D	Neutralization

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	All of these choices are correct
D	Arcing contacts in a thermostatically controlled device

20. - E5A11

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 7.1 MHz and a Q of 150?

Select	Answer
A	47.3 kHz
B	157.8 Hz
C	315.6 Hz
D	23.67 kHz

21. - E5B12

What is admittance?

Select	Answer
A	The unit used for Q factor
B	The inverse of impedance
C	The turns ratio of a transformer
D	The term for the gain of a field effect transistor

22. - E5C07

What is a vector?

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

23. - E5D04

Why are short connections necessary at microwave frequencies?

Select	Answer
A	To increase neutralizing resistance
B	To reduce noise figure
C	To reduce phase shift along the connection
D	Because of ground reflections

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

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

25. - 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	Much higher reverse voltage breakdown
B	Enhanced carrier retention time
C	Controlled reverse avalanche voltage
D	Less forward voltage drop

26. - E6C14

What is the primary advantage of using a Programmable Gate Array (PGA) in a logic circuit?

Select	Answer
A	All of these choices are correct
B	Complex logic functions can be created in a single integrated circuit
C	Many similar gates are less expensive than a mixture of gate types
D	A PGA contains its own internal power supply

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Ferrite
B	Powdered-iron
C	Brass
D	Ceramic

28. - 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

29. - E6F02

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

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

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	Monostable multivibrator
B	T flip-flop
C	J-K flip-flop
D	Astable multivibrator

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common emitter
B	Common collector
C	Emitter follower
D	Common base

32. - E7C13

What is one advantage of a Pi-matching network over an L-matching network consisting of a single inductor and a single capacitor?

Select	Answer
A	Pi-networks are designed for balanced input and output
B	Pi-networks have fewer components
C	L-networks cannot perform impedance transformation
D	The Q of Pi-networks can be varied depending on the component values chosen

33. - E7D05

Which of the following types of linear voltage regulator places a constant load on the unregulated voltage source?

Select	Answer
A	A shunt current source
B	A series regulator
C	A constant current source
D	A shunt regulator

34. - E7E12

What is a frequency discriminator stage in a FM receiver?

Select	Answer
A	An automatic band-switching circuit
B	An FM generator circuit
C	A circuit for detecting FM signals
D	A circuit for filtering two closely adjacent signals

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Interpolate by a factor of three, then decimate by a factor of four
B	Change the gain by a factor of 3/4
C	Add 3 to each input value and subtract 4 from each output value
D	Multiply each sample value by a factor of 3/4

36. - E7G11

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 3300 ohms and RF is 47 kilohms?

Select	Answer
A	14
B	0.07
C	28
D	7

37. - E7H15

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

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

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Fourier analysis
B	Numerical analysis
C	Differential analysis
D	Vector analysis

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	0.214
B	2.14
C	47
D	0.47

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It increases security
B	It has more resolution than simple binary
C	It facilitates error detection
D	It has more possible states than simple binary

41. - E8D04

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

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

42. - E9A09

How is antenna efficiency calculated?

Select	Answer
A	(radiation resistance / total resistance) x 100 per cent
B	(effective radiated power / transmitter output) x 100 percent
C	(total resistance / radiation resistance) x 100 per cent
D	(radiation resistance / transmission resistance) x 100 per cent

43. - 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 distinct value of voltage across it
B	A wire is modeled as a single sine-wave current generator
C	A wire is modeled as a series of points, each having a distinct location in space
D	A wire is modeled as a series of segments, each having a uniform value of current

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole one-quarter wavelength long
B	A type of ground-plane antenna
C	A dipole consisting of one wavelength of wire forming a very thin loop
D	A dipole configured to provide forward gain

45. - E9D01

How does the gain of an ideal parabolic dish antenna change when the operating frequency is doubled?

Select	Answer
A	Gain is multiplied by 0.707
B	Gain does not change
C	Gain increases by 6 dB
D	Gain increases by 3 dB

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 the universal stub matching technique
B	Use a 50 ohm 1:1 balun between the antenna and feed line
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. - E9F03

Why is the physical length of a coaxial cable transmission line shorter than its electrical length?

Select	Answer
A	Skin effect is less pronounced in the coaxial cable
B	The characteristic impedance is higher in a parallel feed line
C	The surge impedance is higher in a parallel feed line
D	Electrical signals move more slowly in a coaxial cable than in air

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The current axis
C	The voltage axis
D	The reactance axis

49. - E9H07

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

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

50. - E0A08

What does SAR measure?

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

Figure E7-1

Figure E7-4

Figure E9-3