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

Logging in (or registering) will help the system to select questions that you need to focus on.

1. - E1A08

If a station in a message forwarding system inadvertently forwards a message that is in violation of FCC rules, who is primarily accountable for the rules violation?

Select	Answer
A	The control operator of the originating station
B	The control operators of all the stations in the system
C	The control operator of the packet bulletin board station
D	The control operators of all the stations in the system not authenticating the source from which they accept communications

2. - E1B11

What is the permitted mean power of any spurious emission relative to the mean power of the fundamental emission from a station transmitter or external RF amplifier installed after January 1, 2003 and transmitting on a frequency below 30 MHZ?

Select	Answer
A	At least 73 dB below
B	At least 53 dB below
C	At least 43 dB below
D	At least 63 dB below

3. - E1C10

What types of amateur stations may automatically retransmit the radio signals of other amateur stations?

Select	Answer
A	Only auxiliary, beacon or space stations
B	Only earth stations, repeater stations or model craft
C	Only auxiliary, repeater or space stations
D	Only beacon, repeater or space stations

4. - E1D09

Which UHF amateur service bands have frequencies available for a space station?

Select	Answer
A	70 cm only
B	70 cm and 33 cm
C	70 cm and 13 cm
D	33 cm and 13 cm

5. - E1E07

What should a VE do if a candidate fails to comply with the examiner's instructions during an amateur operator license examination?

Select	Answer
A	Warn the candidate that continued failure to comply will result in termination of the examination
B	Immediately terminate the candidate's examination
C	Immediately terminate everyone's examination and close the session
D	Allow the candidate to complete the examination, but invalidate the results

6. - E1F09

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

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

7. - E2A10

Why may the received signal from an amateur satellite exhibit a rapidly repeating fading effect?

Select	Answer
A	Because of ionospheric absorption
B	Because of the Doppler Effect
C	Because of the satellite's low orbital altitude
D	Because the satellite is spinning

8. - E2B07

What is the name of the signal component that carries color information in NTSC video?

Select	Answer
A	Chroma
B	Hue
C	Spectral Intensity
D	Luminance

9. - E2C13

What indicator is required to be used by U.S.-licensed operators when operating a station via remote control where the transmitter is located in the U.S.?

Select	Answer
A	No additional indicator is required
B	/ followed by the USPS two letter abbreviation for the state in which the remote station is located
C	/R# where # is the district of the remote station
D	The ARRL section of the remote station

10. - E2D07

What digital protocol is used by APRS?

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

11. - E2E11

What is the difference between direct FSK and audio FSK?

Select	Answer
A	Direct FSK uses a DC-coupled data connection
B	Direct FSK applies the data signal to the transmitter VFO
C	Audio FSK can be performed anywhere in the transmit chain
D	Audio FSK has a superior frequency response

12. - E3A11

What is a typical range for tropospheric propagation of microwave signals?

Select	Answer
A	1200 miles
B	10 miles to 50 miles
C	2500 miles
D	100 miles to 300 miles

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	They become phase-locked
C	Their polarization is randomly modified
D	They become elliptically polarized

14. - E3C08

What does the space weather term G5 mean?

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

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A wattmeter
B	A time-domain reflectometer
C	A spectrum analyzer
D	A logic analyzer

16. - E4B12

What is the significance of voltmeter sensitivity expressed in ohms per volt?

Select	Answer
A	The full scale reading of the voltmeter multiplied by its ohms per volt rating will indicate the input impedance of the voltmeter
B	When used as an ohmmeter, the reading in ohms divided by the ohms per volt rating will determine the voltage applied to the circuit
C	When used as an ammeter, the full scale reading in amps divided by ohms per volt rating will determine the size of shunt needed
D	When used as a galvanometer, the reading in volts multiplied by the ohms per volt rating will determine the power drawn by the device under test

17. - E4C16

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

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

18. - E4D01

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

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

19. - E4E07

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

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

20. - E5A10

How is the Q of an RLC series resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance times the reactance of the capacitance
C	Reactance of either the inductance or capacitance divided by the resistance
D	Reactance of either the inductance or capacitance times the resistance

21. - E5B05

What happens to the magnitude of a reactance when it is converted to a susceptance?

Select	Answer
A	The sign is reversed
B	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance
C	It is shifted by 90 degrees
D	It is unchanged

22. - E5C10

When using rectangular coordinates to graph the impedance of a circuit, what does the vertical axis represent?

Select	Answer
A	The difference between the resistive and reactive components
B	The sum of the reactive and resistive components
C	Resistive component
D	Reactive component

23. - E5D04

Why are short connections necessary at microwave frequencies?

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

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter voltage of approximately 0.6 to 0.7 volts
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter resistance of approximately 6 to 7 ohms

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Reverse bias controls its forward voltage drop
B	A large region of intrinsic material
C	Ability to dissipate large amounts of power
D	Extremely high reverse breakdown voltage

26. - E6C04

What is the primary advantage of tri-state logic?

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

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 lower initial permeability
C	Ferrite toroids generally require fewer turns to produce a given inductance value
D	Ferrite toroids generally have better temperature stability

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	44 dBm
D	-20 dBm

29. - E6F05

Which describes an optical shaft encoder?

Select	Answer
A	A device which detects rotation of a control by interrupting a light source with a patterned wheel
B	A device for generating RTTY signals by means of a rotating light source
C	A device which measures the strength of a beam of light using analog to digital conversion
D	A digital encryption device often used to encrypt spacecraft control signals

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	A flip-flop
B	An "AND" gate
C	A clock
D	An "OR" gate

31. - E7B08

How can an RF power amplifier be neutralized?

Select	Answer
A	By feeding a 180-degree out-of-phase portion of the output back to the input
B	By feeding an in-phase component of the output back to the input
C	By increasing the driving power
D	By reducing the driving power

32. - E7C02

Which of the following is a property of a T-network with series capacitors and a parallel shunt inductor?

Select	Answer
A	It is a band-pass filter
B	It is a high-pass filter
C	It is a notch filter
D	It is a low-pass filter

33. - E7D03

What device is typically used as a stable reference voltage in a linear voltage regulator?

Select	Answer
A	A varactor diode
B	A Zener diode
C	A tunnel diode
D	An SCR

34. - E7E03

How does an analog phase modulator function?

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

35. - E7F06

What is the minimum number of bits required for an analog-to-digital converter to sample a signal with a range of 1 volt at a resolution of 1 millivolt?

Select	Answer
A	8 bits
B	6 bits
C	10 bits
D	4 bits

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	7
B	28
C	0.07
D	14

37. - E7H02

Which describes a microphonic?

Select	Answer
A	An IC used for amplifying microphone signals
B	Changes in oscillator frequency due to mechanical vibration
C	Distortion caused by RF pickup on the microphone cable
D	Excess loading of the microphone by an oscillator

38. - E8A12

What is an advantage of using digital signals instead of analog signals to convey the same information?

Select	Answer
A	Digital signals can be regenerated multiple times without error
B	Less complex circuitry is required for digital signal generation and detection
C	All of these choices are correct
D	Digital signals always occupy a narrower bandwidth

39. - E8B05

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus-or-minus 5 kHz when the maximum modulation frequency is 3 kHz?

Select	Answer
A	0.6
B	0.167
C	1.67
D	60

40. - E8C11

What is the relationship between symbol rate and baud?

Select	Answer
A	They are the same
B	Baud is twice the symbol rate
C	Baud is only used for RTTY
D	Symbol rate is only used for packet-based modes

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The receiver is always equipped with a digital blanker
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	Signals not using the spread spectrum algorithm are suppressed in the receiver
D	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered

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	Antenna height, conductor length/diameter ratio and location of nearby conductive objects
C	Transmission-line length
D	The settings of an antenna tuner at the transmitter

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	Ground conductivity will not be accurately modeled
B	The computed feed point impedance may be incorrect
C	The resulting design will favor radiation of harmonic energy
D	The antenna will become mechanically unstable

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	An eight band dipole antenna using octophase filters
B	A multiband dipole antenna using one-way circular polarization for frequency diversity
C	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
D	A remotely tunable dipole antenna using orthogonally controlled frequency diversity

45. - E9D10

What happens to feed point impedance at the base of a fixed length HF mobile antenna as the frequency of operation is lowered?

Select	Answer
A	The radiation resistance decreases and the capacitive reactance decreases
B	The radiation resistance increases and the capacitive reactance increases
C	The radiation resistance decreases and the capacitive reactance increases
D	The radiation resistance increases and the capacitive reactance decreases

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 omega match
B	The delta match
C	The gamma match
D	The stub match

47. - E9F01

What is the velocity factor of a transmission line?

Select	Answer
A	The velocity of the wave in the transmission line multiplied by the velocity of light in a vacuum
B	The index of shielding for coaxial cable
C	The ratio of the characteristic impedance of the line to the terminating impedance
D	The velocity of the wave in the transmission line divided by the velocity of light in a vacuum

48. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Voltage circles and current arcs
B	Resistance lines and reactance chords
C	Resistance circles and reactance arcs
D	Voltage lines and current chords

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	A fixed receiving station plots three headings to the signal source
D	The geometric angles of sky waves from the source are used to determine its position

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated Biphenyls
B	Polytetrafluroethylene
C	Polymorphic silicon
D	Polyethylene

Figure E7-4