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	At the highest frequency of the channel
B	At the lowest frequency of the channel
C	At the center frequency of the channel
D	On any frequency where the signal's sidebands are within the channel

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	2.0
B	0.5
C	1.0
D	3.0

3. - E1C13

Which of the following is required in order to operate in accordance with CEPT rules in foreign countries where permitted?

Select	Answer
A	You must append "/CEPT" to your call sign
B	The U.S. embassy must approve of your operation
C	You must identify in the official language of the country in which you are operating
D	You must bring a copy of FCC Public Notice DA 11-221

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	2 meters and 1.25 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters
D	6 meters and 2 meters

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	Each General, Advanced and Amateur Extra Class operator is automatically accredited as a VE when the license is granted
C	The amateur operator applying must pass a VE examination administered by the FCC Enforcement Bureau
D	The prospective VE obtains accreditation from the FCC

6. - E1F10

What is the maximum permitted transmitter peak envelope power for an amateur station transmitting spread spectrum communications?

Select	Answer
A	10 W
B	1.5 kW
C	1 W
D	1.5 W

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

8. - E2B18

On which of the following frequencies is one likely to find FM ATV transmissions?

Select	Answer
A	14.230 MHz
B	52.525 MHz
C	1255 MHz
D	29.6 MHz

9. - E2C09

What type of equipment is commonly used to implement a ham radio mesh network?

Select	Answer
A	A 2 meter VHF transceiver with a 1200 baud modem
B	A standard wireless router running custom software
C	An optical cable connection between the USB ports of 2 separate computers
D	A 440 MHz transceiver with a 9600 baud modem

10. - E2D02

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

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

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. - E3A11

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

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

13. - E3B11

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

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

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Eastward
B	Southward
C	Northward
D	Westward

15. - E4A11

Which of the following is good practice when using an oscilloscope probe?

Select	Answer
A	All of these choices are correct
B	Never use a DC-coupled probe to measure an AC circuit
C	Never use a high impedance probe to measure a low impedance circuit
D	Keep the signal ground connection of the probe as short as possible

16. - E4B14

What happens if a dip meter is too tightly coupled to a tuned circuit being checked?

Select	Answer
A	A less accurate reading results
B	Intermodulation distortion occurs
C	Harmonics are generated
D	Cross modulation occurs

17. - E4C03

What is the term for the blocking of one FM phone signal by another, stronger FM phone signal?

Select	Answer
A	Capture effect
B	Cross-modulation interference
C	Frequency discrimination
D	Desensitization

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 third order intercept point
B	The difference in dB between the noise floor and the level of an incoming signal which will cause 1 dB of gain compression
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. - E4E02

Which of the following types of receiver noise can often be reduced with a DSP noise filter?

Select	Answer
A	All of these choices are correct
B	Broadband white noise
C	Ignition noise
D	Power line noise

20. - E5A04

What is the magnitude of the impedance of a circuit with a resistor, an inductor and a capacitor all in parallel, at resonance?

Select	Answer
A	Low, as compared to the circuit resistance
B	Approximately equal to inductive reactance
C	Approximately equal to circuit resistance
D	Approximately equal to capacitive reactance

21. - E5B03

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

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

22. - E5C09

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

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

23. - E5D04

Why are short connections necessary at microwave frequencies?

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

24. - E6A05

What is the alpha of a bipolar junction transistor?

Select	Answer
A	The change of collector current with respect to emitter current
B	The change of base current with respect to collector current
C	The change of collector current with respect to gate current
D	The change of collector current with respect to base current

25. - E6B04

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

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

26. - E6C10

In Figure E6-5, what is the schematic symbol for a NOR gate?

Select	Answer
A	4
B	1
C	3
D	2

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

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	450 ohms
B	50 ohms
C	10 ohms
D	300 ohms

29. - E6F08

Why are optoisolators often used in conjunction with solid state circuits when switching 120VAC?

Select	Answer
A	Optoisolators provide a low impedance link between a control circuit and a power circuit
B	Optoisolators eliminate the effects of reflected light in the control circuit
C	Optoisolators provide a very high degree of electrical isolation between a control circuit and the circuit being switched
D	Optoisolators provide impedance matching between the control circuit and power circuit

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Emitter load
B	Voltage regulation
C	Collector load
D	Fixed bias

32. - E7C15

What is a crystal lattice filter?

Select	Answer
A	A filter with wide bandwidth and shallow skirts made using quartz crystals
B	An audio filter made with four quartz crystals that resonate at 1kHz intervals
C	A power supply filter made with interlaced quartz crystals
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. - E7E02

What is the function of a reactance modulator?

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

35. - E7F05

How frequently must an analog signal be sampled by an analog-to-digital converter so that the signal can be accurately reproduced?

Select	Answer
A	At half the rate of the highest frequency component of the signal
B	At four times the rate of the highest frequency component of the signal
C	At the same rate as the highest frequency component of the signal
D	At twice the rate of the highest frequency component of the signal

36. - E7G02

What is the effect of ringing in a filter?

Select	Answer
A	Partial cancellation of the signal over a range of frequencies
B	An echo caused by a long time delay
C	Undesired oscillations added to the desired signal
D	A reduction in high frequency response

37. - E7H10

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

Select	Answer
A	The amplitude values that represent a sine-wave output
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 synthesizer frequency limits and frequency values stored in the radio memories

38. - E8A03

What type of wave does a Fourier analysis show to be made up of sine waves of a given fundamental frequency plus all of its harmonics?

Select	Answer
A	A cosine wave
B	A sawtooth wave
C	A square wave
D	A sine wave

39. - E8B04

What is the modulation index of an FM-phone signal having a maximum carrier deviation of plus or minus 6 kHz when modulated with a 2 kHz modulating frequency?

Select	Answer
A	6000
B	1/3
C	3
D	2000

40. - E8C09

Which is the name of a digital code where each preceding or following character changes by only one bit?

Select	Answer
A	Excess 3 code
B	Binary Coded Decimal Code
C	Extended Binary Coded Decimal Interchange Code
D	Gray code

41. - E8D07

What is a common cause of overmodulation of AFSK signals?

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

42. - E9A02

What antenna has no gain in any direction?

Select	Answer
A	Quarter-wave vertical
B	Yagi
C	Half-wave dipole
D	Isotropic antenna

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna
C	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
D	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference

44. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A dipole configured to provide forward gain
B	A type of ground-plane antenna
C	A dipole consisting of one wavelength of wire forming a very thin loop
D	A dipole one-quarter wavelength long

45. - E9D09

What is the function of a loading coil used as part of an HF mobile antenna?

Select	Answer
A	To lower the Q
B	To lower the losses
C	To cancel capacitive reactance
D	To increase the SWR bandwidth

46. - E9E12

What is the primary purpose of a phasing line when used with an antenna having multiple driven elements?

Select	Answer
A	It ensures that each driven element operates in concert with the others to create the desired antenna pattern
B	It allows single-band antennas to operate on other bands
C	It makes sure the antenna has a low-angle radiation pattern
D	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter

47. - E9F01

What is the velocity factor of a transmission line?

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

48. - E9G07

On the Smith chart shown in Figure E9-3, what is the only straight line shown?

Select	Answer
A	The resistance axis
B	The voltage axis
C	The current axis
D	The reactance axis

49. - E9H02

Which is generally true for low band (160 meter and 80 meter) receiving antennas?

Select	Answer
A	All of these choices are correct
B	Low loss coax transmission line is essential for good performance
C	Atmospheric noise is so high that gain over a dipole is not important
D	They must be erected at least 1/2 wavelength above the ground to attain good directivity

50. - E0A06

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

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

Figure E6-5

Figure E7-2

Figure E9-3