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. - 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	Military Auxiliary Radio System (MARS) channels
D	Specific segments in the amateur service MF, HF, VHF and UHF bands

3. - E1C11

Which of the following operating arrangements allows an FCC-licensed U.S. citizen to operate in many European countries, and alien amateurs from many European countries to operate in the U.S.?

Select	Answer
A	ITU reciprocal license
B	IARP agreement
C	All of these choices are correct
D	CEPT agreement

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 spacecraft launching service for amateur-built satellites
C	A radio communications service using stations on Earth satellites for public service broadcast
D	A radio communications service using amateur radio stations on satellites

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 70%
C	Minimum passing score of 74%
D	Minimum passing score of 77%

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	All of these choices are correct
D	A station transmitting SS emission must not cause harmful interference to other stations employing other authorized emissions

7. - E2A14

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

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

8. - E2B13

How many lines are commonly used in each frame of an amateur slow-scan color television picture?

Select	Answer
A	30 or 60
B	128 or 256
C	60 or 100
D	180 or 360

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

10. - E2D02

Which of the following is a good technique for making meteor scatter contacts?

Select	Answer
A	Short transmission with rapidly repeated call signs and signal reports
B	Use of high speed CW or digital modes
C	15 second timed transmission sequences with stations alternating based on location
D	All of these choices are correct

11. - E2E09

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

Select	Answer
A	PACTOR
B	RTTY
C	MT63
D	PSK31

12. - E3A04

What do Hepburn maps predict?

Select	Answer
A	Probability of tropospheric propagation
B	Likelihood of rain-scatter along cold or warm fronts
C	Sporadic E propagation
D	Locations of auroral reflecting zones

13. - E3B02

What is the approximate maximum range for signals using transequatorial propagation?

Select	Answer
A	5000 miles
B	7500 miles
C	1000 miles
D	2500 miles

14. - E3C11

What does VOACAP software model?

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

15. - E4A10

Which of the following displays multiple digital signal states simultaneously?

Select	Answer
A	Network analyzer
B	Bit error rate tester
C	Logic analyzer
D	Modulation monitor

16. - E4B17

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

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

17. - E4C08

An SDR receiver is overloaded when input signals exceed what level?

Select	Answer
A	The maximum count value of the analog-to-digital converter
B	One-half the maximum sampling buffer size
C	One-half the maximum sample rate
D	The reference voltage of the analog-to-digital converter

18. - E4D12

What is the term for the reduction in receiver sensitivity caused by a strong signal near the received frequency?

Select	Answer
A	Desensitization
B	Squelch gain rollback
C	Quieting
D	Cross-modulation interference

19. - E4E11

Which is the most likely cause if you are hearing combinations of local AM broadcast signals within one or more of the MF or HF ham bands?

Select	Answer
A	Nearby corroded metal joints are mixing and re-radiating the broadcast signals
B	The broadcast station is transmitting an over-modulated signal
C	Your station receiver IF amplifier stage is defective
D	You are receiving sky wave signals from a distant station

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	315.6 Hz
B	157.8 Hz
C	23.67 kHz
D	47.3 kHz

21. - E5B03

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

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

22. - E5C03

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

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

23. - E5D18

How many watts are consumed in a circuit having a power factor of 0.71 if the apparent power is 500VA?

Select	Answer
A	704 W
B	252 W
C	355 W
D	1.42 mW

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that exhibits a current flow between source and drain when no gate voltage is applied
C	Any FET for which holes are the majority carriers
D	An FET that has no current flow between source and drain when no gate voltage is applied

25. - E6B03

What special type of diode is capable of both amplification and oscillation?

Select	Answer
A	Point contact
B	Tunnel
C	Junction
D	Zener

26. - E6C04

What is the primary advantage of tri-state logic?

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

27. - E6D12

What is the definition of saturation in a ferrite core inductor?

Select	Answer
A	Adjacent inductors become over-coupled
B	The inductor's voltage rating is exceeded causing a flashover
C	The ability of the inductor's core to store magnetic energy has been exceeded
D	The inductor windings are over coupled

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon
B	Silicon nitride
C	Silicon dioxide
D	Gallium nitride

29. - E6F12

What absorbs the energy from light falling on a photovoltaic cell?

Select	Answer
A	Electrons
B	Photons
C	Holes
D	Protons

30. - E7A04

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

Select	Answer
A	8
B	1
C	4
D	2

31. - E7B17

Why are odd-order rather than even-order intermodulation distortion products of concern in linear power amplifiers?

Select	Answer
A	Because they are relatively far in frequency from the desired signal
B	Because they invert the sidebands causing distortion
C	Because they are relatively close in frequency to the desired signal
D	Because they maintain the sidebands, thus causing multiple duplicate signals

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A notch filter
B	An all-pass filter
C	A band-pass filter
D	A Pi-network filter

33. - E7D09

What is the main reason to use a charge controller with a solar power system?

Select	Answer
A	Prevention of battery undercharge
B	Prevention of battery damage due to overcharge
C	Matching of day and night charge rates
D	Control of electrolyte levels during battery discharge

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By using a balanced modulator followed by a filter
B	By driving a product detector with a DSB signal
C	By using a reactance modulator followed by a mixer
D	By using a loop modulator followed by a mixer

35. - E7F16

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

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

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	0.07
C	7
D	14

37. - E7H14

What is a phase-locked loop circuit?

Select	Answer
A	An electronic circuit also known as a monostable multivibrator
B	An electronic servo loop consisting of a ratio detector, reactance modulator, and voltage-controlled oscillator
C	An electronic servo loop consisting of a phase detector, a low-pass filter, a voltage-controlled oscillator, and a stable reference oscillator
D	An electronic circuit consisting of a precision push-pull amplifier with a differential input

38. - E8A06

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

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

39. - E8B02

How does the modulation index of a phase-modulated emission vary with RF carrier frequency (the modulated frequency)?

Select	Answer
A	It increases as the RF carrier frequency increases
B	It does not depend on the RF carrier frequency
C	It varies with the square root of the RF carrier frequency
D	It decreases as the RF carrier frequency increases

40. - E8C05

What is the necessary bandwidth of a 13-WPM international Morse code transmission?

Select	Answer
A	Approximately 26 Hz
B	Approximately 104 Hz
C	Approximately 52 Hz
D	Approximately 13 Hz

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Repeat Request Rate (RRR)
B	Baud rate
C	Intermodulation Distortion (IMD)
D	Signal to noise ratio

42. - E9A06

How does the beamwidth of an antenna vary as the gain is increased?

Select	Answer
A	It increases geometrically
B	It decreases
C	It is essentially unaffected
D	It increases arithmetically

43. - E9B14

What type of information can be obtained by submitting the details of a proposed new antenna to a modeling program?

Select	Answer
A	Antenna gain
B	SWR vs frequency charts
C	All of these choices are correct
D	Polar plots of the far field elevation and azimuth patterns

44. - E9C12

Which of the following describes an extended double Zepp antenna?

Select	Answer
A	A portable antenna erected using two push support poles
B	A wideband vertical antenna constructed from precisely tapered aluminum tubing
C	A center fed 1.25 wavelength antenna (two 5/8 wave elements in phase)
D	An end fed folded dipole antenna

45. - E9D05

What is a disadvantage of using a multiband trapped antenna?

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

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	A reflection coefficient greater than 1
D	An SWR less than 1:1

47. - E9F11

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

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

48. - E9G01

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

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

49. - E9H08

What is the function of a sense antenna?

Select	Answer
A	It modifies the pattern of a DF antenna array to provide a null in one direction
B	It increases the sensitivity of a DF antenna array
C	It allows DF antennas to receive signals at different vertical angles
D	It provides diversity reception that cancels multipath signals

50. - E0A06

Why are there separate electric (E) and magnetic (H) field MPE limits?

Select	Answer
A	E field and H field radiation intensity peaks can occur at different locations
B	Ground reflections and scattering make the field impedance vary with location
C	All of these choices are correct
D	The body reacts to electromagnetic radiation from both the E and H fields

Figure E7-4