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

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1. - E1A07

Which amateur band requires transmission on specific channels rather than on a range of frequencies?

Select	Answer
A	30 meter band
B	12 meter band
C	17 meter band
D	60 meter band

2. - E1B10

What frequencies are authorized to an amateur station operating under RACES rules?

Select	Answer
A	Specific local government channels
B	All amateur service frequencies authorized to the control operator
C	Specific segments in the amateur service MF, HF, VHF and UHF bands
D	Military Auxiliary Radio System (MARS) channels

3. - E1C05

When may an automatically controlled station originate third party communications?

Select	Answer
A	When agreed upon by the sending or receiving station
B	Only when transmitting RTTY or data emissions
C	When approved by the National Telecommunication and Information Administration
D	Never

4. - E1D11

Which amateur stations are eligible to operate as Earth stations?

Select	Answer
A	Only those of Amateur Extra Class operators
B	Only those of General, Advanced or 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. - E1E04

Which of the following best describes the Volunteer Examiner accreditation process?

Select	Answer
A	The procedure by which a VEC confirms that the VE applicant meets FCC requirements to serve as an examiner
B	The prospective VE obtains accreditation from the FCC
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted

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 be capable of external RF switching between its input and output networks
C	It must satisfy the FCC's spurious emission standards when operated at the lesser of 1500 watts or its full output power
D	It must produce full legal output when driven by not more than 5 watts of mean RF input power

7. - E2A14

What technology is used to track, in real time, balloons carrying amateur radio transmitters?

Select	Answer
A	Radar
B	Bandwidth compressed LORAN
C	Doppler shift of beacon signals
D	APRS

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
B	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	A type of modulation in which one sideband is inverted

9. - E2C11

How should you generally identify your station when attempting to contact a DX station during a contest or in a pileup?

Select	Answer
A	Send only the last two letters of your call sign until you make contact
B	Send your full call sign and grid square
C	Send your full call sign once or twice
D	Send the call sign of the DX station three times, the words "this is", then your call sign three times

10. - E2D08

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

Select	Answer
A	Connect
B	Acknowledgement
C	Disconnect
D	Unnumbered Information

11. - E2E11

What is the difference between direct FSK and audio FSK?

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

12. - E3A07

Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?

Select	Answer
A	Bodies of water
B	Urban areas
C	Forests
D	Mountain ranges

13. - E3B08

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

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

14. - E3C11

What does VOACAP software model?

Select	Answer
A	AC current and impedance
B	AC voltage and impedance
C	VHF radio propagation
D	HF propagation

15. - E4A02

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

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

16. - E4B17

What three test loads are used to calibrate a standard RF vector network analyzer?

Select	Answer
A	50 ohms through 1/8 wavelength, 1/4 wavelength, and 1/2 wavelength of coaxial cable
B	Short circuit, open circuit, and 50 ohms
C	50 ohms, 75 ohms, and 90 ohms
D	Short circuit, open circuit, and resonant circuit

17. - E4C06

A CW receiver with the AGC off has an equivalent input noise power density of -174 dBm/Hz. What would be the level of an unmodulated carrier input to this receiver that would yield an audio output SNR of 0 dB in a 400 Hz noise bandwidth?

Select	Answer
A	-164 dBm
B	-155 dBm
C	-148 dBm
D	-174 dBm

18. - E4D11

Why are third-order intermodulation products created within a receiver of particular interest compared to other products?

Select	Answer
A	Third-order products are an indication of poor image rejection
B	The third-order intercept is much higher than other orders
C	The third-order product of two signals which are in the band of interest is also likely to be within the band
D	Third-order intermodulation produces three products for every input signal within the band of interest

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a bypass capacitor in series with the motor leads
B	By using a ground-fault current interrupter in the circuit used to power the motor
C	By installing a brute-force AC-line filter in series with the motor leads
D	By installing a high pass filter in series with the motor's power leads

20. - E5A13

What is an effect of increasing Q in a resonant circuit?

Select	Answer
A	Parasitic effects are minimized
B	Internal voltages and circulating currents increase
C	Phase shift can become uncontrolled
D	Fewer components are needed for the same performance

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	It is shifted by 90 degrees
C	It is unchanged
D	The magnitude of the susceptance is the reciprocal of the magnitude of the reactance

22. - E5C05

What is the name of the diagram used to show the phase relationship between impedances at a given frequency?

Select	Answer
A	Far field diagram
B	Near field diagram
C	Venn diagram
D	Phasor diagram

23. - E5D06

In what direction is the magnetic field oriented about a conductor in relation to the direction of electron flow?

Select	Answer
A	In all directions; omni-directional
B	In a direction opposite to the current
C	In the same direction as the current
D	In a direction determined by the left-hand rule

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 0.6 to 0.7 volts
B	Base-to-emitter voltage of approximately 6 to 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. - 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	Less forward voltage drop
D	Controlled reverse avalanche voltage

26. - E6C04

What is the primary advantage of tri-state logic?

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

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From approximately 10 Hz to no more than 3000 kHz
B	From less than 20 Hz to approximately 300 MHz
C	From a few kHz to no more than 30 MHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E02

Which of the following device packages is a through-hole type?

Select	Answer
A	PLCC
B	DIP
C	Ball grid array
D	SOT

29. - E6F02

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

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

30. - E7A08

What logical operation does an OR gate perform?

Select	Answer
A	It produces logic "1" at its output if any or all inputs are logic "1"
B	It produces logic "1" at its output if all inputs are logic "0"
C	It produces logic "0" at its output if all inputs are logic "1"
D	It only produces logic "0" at its output when all inputs are logic "1"

31. - E7B18

What is a characteristic of a grounded-grid amplifier?

Select	Answer
A	Low bandwidth
B	High power gain
C	High filament voltage
D	Low input impedance

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

33. - E7D03

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

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

34. - E7E02

What is the function of a reactance modulator?

Select	Answer
A	To produce PM signals by using an electrically variable inductance or capacitance
B	To produce AM signals by using an electrically variable inductance or capacitance
C	To produce PM signals by using an electrically variable resistance
D	To produce AM signals by using an electrically variable resistance

35. - E7F04

What is a common method of generating an SSB signal using digital signal processing?

Select	Answer
A	Combine signals with a quadrature phase relationship
B	Emulation of quartz crystal filter characteristics
C	Mixing products are converted to voltages and subtracted by adder circuits
D	A frequency synthesizer removes the unwanted sidebands

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	28
B	14
C	0.07
D	7

37. - E7H10

What information is contained in the lookup table of a direct digital frequency synthesizer?

Select	Answer
A	The synthesizer frequency limits and frequency values stored in the radio memories
B	The phase relationship between a reference oscillator and the output waveform
C	The phase relationship between a voltage-controlled oscillator and the output waveform
D	The amplitude values that represent a sine-wave output

38. - E8A09

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

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

39. - E8B03

What is the modulation index of an FM-phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency when the modulating frequency is 1000 Hz?

Select	Answer
A	1000
B	0.3
C	3000
D	3

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 facilitates error detection
C	It has more possible states than simple binary
D	It has more resolution than simple binary

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

Select	Answer
A	Ground loops
B	Excessive transmit audio levels
C	Excessive numbers of retries
D	Bit errors in the modem

42. - E9A04

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

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

43. - E9B06

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

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

44. - E9C03

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced a 1/2 wavelength apart and fed in phase?

Select	Answer
A	Cardioid
B	A Figure-8 end-fire along the axis of the array
C	Omni-directional
D	A Figure-8 broadside to the axis of the array

45. - E9D08

What happens as the Q of an antenna increases?

Select	Answer
A	SWR bandwidth decreases
B	Gain is reduced
C	SWR bandwidth increases
D	More common-mode current is present on the feed line

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	A dielectric constant greater than 1
B	An SWR greater than 1:1
C	An SWR less than 1:1
D	A reflection coefficient greater than 1

47. - E9F14

What impedance does a 1/2 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	Very high impedance
C	Very low impedance
D	The same as the output impedance of the generator

48. - E9G01

Which of the following can be calculated using a Smith chart?

Select	Answer
A	Radio propagation
B	Antenna radiation pattern
C	Radiation resistance
D	Impedance along transmission lines

49. - E9H04

What is an advantage of using a shielded loop antenna for direction finding?

Select	Answer
A	It automatically cancels ignition noise in mobile installations
B	It allows stations to communicate without giving away their position
C	It is electro statically balanced against ground, giving better nulls
D	It eliminates tracking errors caused by strong out-of-band signals

50. - E0A07

How may dangerous levels of carbon monoxide from an emergency generator be detected?

Select	Answer
A	By the odor
B	By the yellowish appearance of the gas
C	Only with a carbon monoxide detector
D	Any ordinary smoke detector can be used

Figure E7-4

Figure E9-2