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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the DX station initiated the contact
B	Yes, because the displayed frequency is within the 75 meter phone band segment
C	No, the sideband will extend beyond the edge of the phone band segment
D	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	1 mile
C	30 miles
D	3 miles

3. - E1C04

What is meant by IARP?

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

4. - E1D03

What is a telecommand station in the amateur satellite service?

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

5. - E1E05

What is the minimum passing score on amateur operator license examinations?

Select	Answer
A	Minimum passing score of 80%
B	Minimum passing score of 77%
C	Minimum passing score of 70%
D	Minimum passing score of 74%

6. - E1F11

Which of the following best describes one of the standards that must be met by an external RF power amplifier if it is to qualify for a grant of FCC certification?

Select	Answer
A	It must exhibit a gain of 0 dB or less over its full output range
B	It must produce full legal output when driven by not more than 5 watts of mean RF input power
C	It must be capable of external RF switching between its input and output networks
D	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power

7. - E2A09

What do the terms L band and S band specify with regard to satellite communications?

Select	Answer
A	The 23 centimeter and 13 centimeter bands
B	The 2 meter and 70 centimeter bands
C	Which sideband to use
D	FM and Digital Store-and-Forward systems

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	120
B	60
C	30
D	90

9. - E2C05

What is the function of a DX QSL Manager?

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

10. - E2D08

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

Select	Answer
A	Disconnect
B	Unnumbered Information
C	Acknowledgement
D	Connect

11. - E2E02

What do the letters FEC mean as they relate to digital operation?

Select	Answer
A	Fatal Error Correction
B	First Error Correction
C	Final Error Correction
D	Forward Error Correction

12. - E3A08

When a meteor strikes the Earth's atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

Select	Answer
A	The D layer
B	The E layer
C	The F1 layer
D	The F2 layer

13. - E3B11

At what time of day is Sporadic-E propagation most likely to occur?

Select	Answer
A	Any time
B	Early evening
C	Around sunset
D	Around sunrise

14. - E3C09

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

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

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	RF amplitude and frequency
B	RF amplitude and time
C	SWR and time
D	SWR and frequency

16. - E4B11

How should an antenna analyzer be connected when measuring antenna resonance and feed point impedance?

Select	Answer
A	Connect the antenna feed line directly to the analyzer's connector
B	Loosely couple the antenna and a dummy load to the analyzer
C	Connect the analyzer via a high-impedance transformer to the antenna
D	Loosely couple the analyzer near the antenna base

17. - E4C16

Which of the following is caused by missing codes in an SDR receiver's analog-to-digital converter?

Select	Answer
A	Excess output level
B	Distortion
C	Loss of sensitivity
D	Overload

18. - E4D01

What is meant by the blocking dynamic range of a receiver?

Select	Answer
A	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
B	The difference in dB between the noise floor and the third order intercept point
C	The minimum difference in dB between the levels of two FM signals which will cause one signal to block the other
D	The minimum difference in dB between two signals which produce third order intermodulation products greater than the noise floor

19. - E4E07

How can you determine if line noise interference is being generated within your home?

Select	Answer
A	By observing the AC power line voltage with a spectrum analyzer
B	By checking the power line voltage with a time domain reflectometer
C	By turning off the AC power line main circuit breaker and listening on a battery operated radio
D	By observing the AC power line waveform with an oscilloscope

20. - E5A12

What is the half-power bandwidth of a parallel resonant circuit that has a resonant frequency of 3.7 MHz and a Q of 118?

Select	Answer
A	31.4 kHz
B	218.3 kHz
C	15.7 kHz
D	436.6 kHz

21. - 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?

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

22. - E5C03

Which of the following represents an inductive reactance in polar coordinates?

Select	Answer
A	A negative phase angle
B	A positive real part
C	A negative real part
D	A positive phase angle

23. - E5D12

How many watts are consumed in a circuit having a power factor of 0.2 if the input is 100-VAC at 4 amperes?

Select	Answer
A	400 watts
B	80 watts
C	50 watts
D	2000 watts

24. - E6A16

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

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

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Silicon-controlled rectifier
B	Zener diode
C	Varactor diode
D	Tunnel diode

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	4
B	3
C	1
D	2

27. - E6D05

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

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

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is a CMOS analog-to-digital converter
B	It is used in a battery charger circuit
C	Its phase shift changes rapidly with frequency
D	It samples an analog signal and passes it in stages from the input to the output

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An LED and a phototransistor
C	A lens and a photomultiplier
D	An amplitude modulated helium-neon laser

30. - E7A04

How many flip-flops are required to divide a signal frequency by 4?

Select	Answer
A	2
B	8
C	4
D	1

31. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Use a phase inverter in the output filter
C	Install parasitic suppressors and/or neutralize the stage
D	Tune both the input and output for maximum power

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A power supply filter made with interlaced quartz crystals
B	A filter with wide bandwidth and shallow skirts made using quartz crystals
C	An audio filter made with four quartz crystals that resonate at 1kHz intervals
D	A filter with narrow bandwidth and steep skirts made using quartz crystals

33. - E7D14

What is one purpose of a "bleeder" resistor in a conventional unregulated power supply?

Select	Answer
A	To cut down on waste heat generated by the power supply
B	To balance the low-voltage filament windings
C	To improve output voltage regulation
D	To boost the amount of output current

34. - E7E08

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

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

35. - E7F08

What is the function of decimation with regard to digital filters?

Select	Answer
A	Removing unnecessary significant digits
B	Reducing the effective sample rate by removing samples
C	Converting data to binary code decimal form
D	Attenuating the signal

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	94
D	24

37. - E7H08

Which of the following components can be used to reduce thermal drift in crystal oscillators?

Select	Answer
A	Wirewound resistors
B	NP0 capacitors
C	Toroidal inductors
D	Non-inductive resistors

38. - E8A09

How many levels can an analog-to-digital converter with 8 bit resolution encode?

Select	Answer
A	256
B	256 divided by the gain of the input amplifier
C	8
D	8 multiplied by the gain of the input amplifier

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. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	9.6 kHz
C	5.76 kHz
D	4.8 kHz

41. - E8D11

What is one advantage of using ASCII code for data communications?

Select	Answer
A	It is possible to transmit both upper and lower case text
B	It uses one character as a shift code to send numeric and special characters
C	It includes built in error correction features
D	It contains fewer information bits per character than any other code

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	Transmission-line length
D	Antenna height, conductor length/diameter ratio and location of nearby conductive objects

43. - E9B06

What is the elevation angle of peak response in the antenna radiation pattern shown in Figure E9-2?

Select	Answer
A	45 degrees
B	7.5 degrees
C	25 degrees
D	75 degrees

44. - E9C04

What happens to the radiation pattern of an unterminated long wire antenna as the wire length is increased?

Select	Answer
A	The vertical angle increases
B	The lobes become more perpendicular to the wire
C	The front-to-back ratio decreases
D	The lobes align more in the direction of the wire

45. - E9D13

What usually occurs if a Yagi antenna is designed solely for maximum forward gain?

Select	Answer
A	The SWR is reduced
B	The front-to-back ratio increases
C	The front-to-back ratio decreases
D	The frequency response is widened over the whole frequency band

46. - E9E10

Which of these choices is an effective way to match an antenna with a 100 ohm feed point impedance to a 50 ohm coaxial cable feed line?

Select	Answer
A	Insert a 1/2 wavelength piece of 300 ohm twin-lead in series between the antenna terminals and the 50 ohm feed cable
B	Insert a 1/4-wavelength piece of 75 ohm coaxial cable transmission line in series between the antenna terminals and the 50 ohm feed cable
C	Connect 1/2 wavelength shorted stub of 75 ohm cable in parallel with the 50 ohm cable where it attaches to the antenna
D	Connect a 1/4-wavelength open stub of 300 ohm twin-lead in parallel with the coaxial feed line where it connects to the antenna

47. - E9F10

What impedance does a 1/8 wavelength transmission line present to a generator when the line is shorted at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	An inductive reactance
C	The same as the input impedance to the final generator stage
D	A capacitive reactance

48. - E9G03

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	It should be configured as a four-sided loop
B	Its overall length must not exceed 1/4 wavelength
C	It must be mounted more than 1 wavelength above ground
D	It should be one or more wavelengths long

50. - E0A02

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

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

Figure E6-5

Figure E7-4

Figure E9-2