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

2. - E1B01

Which of the following constitutes a spurious emission?

Select	Answer
A	An emission outside its necessary bandwidth that can be reduced or eliminated without affecting the information transmitted
B	An amateur station transmission made at random without the proper call sign identification
C	Any transmitted signal that unintentionally interferes with another licensed radio station
D	A signal transmitted to prevent its detection by any station other than the intended recipient

3. - E1C04

What is meant by IARP?

Select	Answer
A	An indication of increased antenna reflected power
B	An international amateur radio permit that allows U.S. amateurs to operate in certain countries of the Americas
C	The internal amateur radio practices policy of the FCC
D	A forecast of intermittent aurora radio propagation

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
B	A radio communications service using amateur radio stations on satellites
C	A spacecraft launching service for amateur-built satellites
D	A radio communications service using stations on Earth satellites for public service broadcast

5. - E1E14

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

6. - E1F12

Who may be the control operator of an auxiliary station?

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

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 maximum height of a satellite's orbit
C	The time it takes for a satellite to travel from perigee to apogee
D	The point of minimum height of a satellite's orbit

8. - E2B15

What signals SSTV receiving equipment to begin a new picture line?

Select	Answer
A	Specific tone amplitudes
B	A two-tone signal
C	Elapsed time
D	Specific tone frequencies

9. - E2C07

What is the Cabrillo format?

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

10. - 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	An APRS station with a GPS unit can automatically transmit information to show a mobile station's position during the event
C	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
D	All of these choices are correct

11. - E2E12

Which type of control is used by stations using the Automatic Link Enable (ALE) protocol?

Select	Answer
A	Automatic
B	Remote
C	Local
D	ALE can use any type of control

12. - E3A09

Which of the following frequency range is most suited for meteor scatter communications?

Select	Answer
A	10 MHz - 14 MHz
B	28 MHz - 148 MHz
C	220 MHz - 450 MHz
D	1.8 MHz - 1.9 MHz

13. - E3B07

Which of the following could account for hearing an echo on the received signal of a distant station?

Select	Answer
A	Meteor scatter
B	Receipt of a signal by more than one path
C	Transmit frequency is higher than the MUF
D	High D layer absorption

14. - E3C08

What does the space weather term G5 mean?

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

15. - E4A05

What might be an advantage of a digital vs an analog oscilloscope?

Select	Answer
A	All of these choices are correct
B	Storage of traces for future reference
C	Automatic amplitude and frequency numerical readout
D	Manipulation of time base after trace capture

16. - E4B09

What is indicated if the current reading on an RF ammeter placed in series with the antenna feed line of a transmitter increases as the transmitter is tuned to resonance?

Select	Answer
A	The transmitter is not properly neutralized
B	There is more power going into the antenna
C	There is an impedance mismatch between the antenna and feed line
D	There is possibly a short to ground in the feed line

17. - E4C11

Which of the following is a desirable amount of selectivity for an amateur SSB phone receiver?

Select	Answer
A	1 kHz
B	4.8 kHz
C	4.2 kHz
D	2.4 kHz

18. - E4D06

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

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

19. - E4E16

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

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

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	Matching bandwidth is decreased
B	It has no effect on impedance matching
C	Matching range is increased
D	Matching bandwidth is increased

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

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

22. - E5C12

If you plot the impedance of a circuit using the rectangular coordinate system and find the impedance point falls on the right side of the graph on the horizontal axis, what do you know about the circuit?

Select	Answer
A	It contains resistance and inductive reactance
B	It has to be a direct current circuit
C	It is equivalent to a pure resistance
D	It contains resistance and capacitive reactance

23. - E5D03

What is microstrip?

Select	Answer
A	Precision printed circuit conductors above a ground plane that provide constant impedance interconnects at microwave frequencies
B	Lightweight transmission line made of common zip cord
C	Miniature coax used for low power applications
D	Short lengths of coax mounted on printed circuit boards to minimize time delay between microwave circuits

24. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Insulator impurity
B	Acceptor impurity
C	N-type impurity
D	Donor impurity

25. - E6B11

What is used to control the attenuation of RF signals by a PIN diode?

Select	Answer
A	Capacitance of an RF coupling capacitor
B	Reverse voltage larger than the RF signal
C	A sub-harmonic pump signal
D	Forward DC bias current

26. - E6C11

In Figure E6-5, what is the schematic symbol for the NOT operation (inverter)?

Select	Answer
A	2
B	5
C	6
D	4

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Snubber capacitor
B	Feedback capacitor
C	Clipper capacitor
D	Trimmer capacitor

28. - E6E05

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

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

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A frequency-determining unit for a transmitter or receiver
B	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
C	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
D	A display that uses a glowing liquid to remain brightly lit in dim light

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "1" at its output only when all inputs are logic "1"
B	It produces logic "0" at its output if some but not all inputs are logic "1"
C	It produces logic "0" at its output only when all inputs are logic "0"
D	It produces logic "0" at its output only when all inputs are logic "1"

31. - E7B12

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

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

32. - E7C01

How are the capacitors and inductors of a low-pass filter Pi-network arranged between the network's input and output?

Select	Answer
A	A capacitor is connected between the input and ground, another capacitor is connected between the output and ground, and an inductor is connected between input and output
B	Two inductors are in series between the input and output, and a capacitor is connected between the two inductors and ground
C	An inductor is connected between the input and ground, another inductor is connected between the output and ground, and a capacitor is connected between the input and output
D	Two capacitors are in series between the input and output, and an inductor is connected between the two capacitors and ground

33. - E7D11

What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Select	Answer
A	Switching inductance
B	Error amplifier
C	Pass transistor
D	Reference voltage

34. - E7E06

Why is de-emphasis commonly used in FM communications receivers?

Select	Answer
A	To reduce impulse noise reception
B	To remove third-order distortion products
C	For compatibility with transmitters using phase modulation
D	For higher efficiency

35. - E7F11

What sets the minimum detectable signal level for an SDR in the absence of atmospheric or thermal noise?

Select	Answer
A	Data storage transfer rate
B	Reference voltage level and sample width in bits
C	Missing codes and jitter
D	Sample clock phase noise

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	47
B	0.21
C	24
D	94

37. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a capacitive divider
B	Through a neutralizing capacitor
C	Through link coupling
D	Through a tapped coil

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	100 to 1
B	1 to 1
C	25 to 1
D	2.5 to 1

39. - E8B09

What is meant by deviation ratio?

Select	Answer
A	The ratio of the carrier center frequency to the audio modulating frequency
B	The ratio of the audio modulating frequency to the center carrier frequency
C	The ratio of the highest audio modulating frequency to the average audio modulating frequency
D	The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	It improves carrier suppression
B	It is easier to demodulate with a conventional, non-synchronous detector
C	This results in the least possible transmitted bandwidth for the particular mode
D	All of these choices are correct

41. - E8D09

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

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

42. - E9A04

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

Select	Answer
A	Sunspot activity and time of day
B	The settings of an antenna tuner at the transmitter
C	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
D	Transmission-line length

43. - E9B16

How many elevation lobes appear in the forward direction of the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	3
B	7
C	1
D	4

44. - E9C07

What is the approximate feed point impedance at the center of a two-wire folded dipole antenna?

Select	Answer
A	450 ohms
B	72 ohms
C	50 ohms
D	300 ohms

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

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

46. - E9E03

What is the name of the matching system that uses a section of transmission line connected in parallel with the feed line at or near the feed point?

Select	Answer
A	The gamma match
B	The delta match
C	The stub match
D	The omega match

47. - E9F06

What is the approximate physical length of an air-insulated, parallel conductor transmission line that is electrically one-half wavelength long at 14.10 MHz?

Select	Answer
A	20 meters
B	15 meters
C	10 meters
D	71 meters

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Reactance axis
C	Impedance axis
D	Prime axis

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	High-radiation angle
B	Broad band response
C	A very sharp single null
D	A very sharp peak

50. - E0A11

Which of the following injuries can result from using high-power UHF or microwave transmitters?

Select	Answer
A	Localized heating of the body from RF exposure in excess of the MPE limits
B	Blood clotting from the intense magnetic field
C	Ingestion of ozone gas from the cooling system
D	Hearing loss caused by high voltage corona discharge

Figure E6-5

Figure E7-1

Figure E7-4

Figure E9-2

Figure E9-3