US Amateur Radio - Amateur Extra (Element 4, 2020-2024) Practice Test

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1. - E0A06

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

Select	Answer
A	All these choices are correct
B	Ground reflections and scattering make the field strength 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

2. - E1A05

What is the maximum power output permitted on the 60 meter band?

Select	Answer
A	100 watts PEP effective radiated power relative to the gain of a half-wave dipole
B	50 watts PEP effective radiated power relative to an isotropic radiator
C	100 watts PEP effective radiated power relative to an isotropic radiator
D	50 watts PEP effective radiated power relative to a dipole

3. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area surrounding the National Radio Astronomy Observatory
B	An area in Puerto Rico surrounding the Arecibo Radio Telescope
C	An area in New Mexico surrounding the White Sands Test Area
D	An area in Florida surrounding Cape Canaveral

4. - E1C13

What notifications must be given before transmitting on the 630 meter or 2200 meter bands?

Select	Answer
A	Operators must inform the FAA of their intent to operate, giving their call sign and distance to the nearest runway
B	Operators must inform the Utilities Technology Council (UTC) of their call sign and coordinates of the station
C	A special endorsement must be requested from the FCC
D	An environmental impact statement must be filed with the Department of the Interior

5. - E1D01

What is the definition of telemetry?

Select	Answer
A	One-way transmission that initiates, modifies, or terminates the functions of a device at a distance
B	Two-way transmissions in excess of 1000 feet
C	Two-way transmissions of data
D	One-way transmission of measurements at a distance from the measuring instrument

6. - E1E10

What must the administering VEs do after the administration of a successful examination for an amateur operator license?

Select	Answer
A	They must collect and send the documents to the NCVEC for grading
B	They must collect and send the documents to the FCC according to instructions
C	They must submit the application document to the coordinating VEC according to the coordinating VEC instructions
D	They must collect and submit the documents to the coordinating VEC for grading

7. - E1F07

When may an amateur station send a message to a business?

Select	Answer
A	When neither the amateur nor his or her employer has a pecuniary interest in the communications
B	When the control operator is employed by the FCC or another government agency
C	When the total money involved does not exceed $25
D	When transmitting international third-party communications

8. - E2A08

Why should effective radiated power to a satellite that uses a linear transponder be limited?

Select	Answer
A	To prevent creating errors in the satellite telemetry
B	To prevent the satellite from emitting out-of-band signals
C	To avoid interfering with terrestrial QSOs
D	To avoid reducing the downlink power to all other users

9. - E2B12

What signals SSTV receiving software to begin a new picture line?

Select	Answer
A	Specific tone frequencies
B	A two-tone signal
C	Elapsed time
D	Specific tone amplitudes

10. - E2C02

Which of the following best describes the term self-spotting? in connection with HF contest operating?

Select	Answer
A	An automatic method for rapidly zero beating or tuning to a station's frequency before calling that station
B	The acceptable practice of manually posting the call signs of stations on a spotting network
C	The often-prohibited practice of posting one's own call sign and frequency on a spotting network
D	A manual technique for rapidly zero beating or tuning to a station's frequency before calling that station

11. - E2D10

How can an APRS station be used to help support a public service communications activity?

Select	Answer
A	APRS stations with General Personnel Scanners can automatically relay the participant numbers and time as they pass the check points
B	An APRS station with an emergency medical technician can automatically transmit medical data to the nearest hospital
C	An APRS station with a Global Positioning System unit can automatically transmit information to show a mobile station's position during the event
D	All these choices are correct

12. - E2E02

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

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

13. - E3A05

Tropospheric propagation of microwave signals often occurs in association with what phenomenon?

Select	Answer
A	Warm and cold fronts
B	Lightning discharges
C	Grayline
D	Sprites and jets

14. - E3B02

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

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

15. - E3C07

Which of the following descriptors indicates the greatest solar flare intensity?

Select	Answer
A	Class X
B	Class B
C	Class A
D	Class M

16. - E4A01

Which of the following limits the highest frequency signal that can be accurately displayed on a digital oscilloscope?

Select	Answer
A	Q of the circuit
B	Sampling rate of the analog-to-digital converter
C	Amount of memory
D	All these choices are correct

17. - E4B08

Which of the following can be used to measure the Q of a series-tuned circuit?

Select	Answer
A	The inductance to capacitance ratio
B	The frequency shift
C	The resonant frequency of the circuit
D	The bandwidth of the circuit's frequency response

18. - E4C13

How does a narrow-band roofing filter affect receiver performance?

Select	Answer
A	It improves intelligibility by using low Q circuitry to reduce ringing
B	It improves dynamic range by attenuating strong signals near the receive frequency
C	It improves sensitivity by reducing front end noise
D	All these choices are correct

19. - E4D08

What causes intermodulation in an electronic circuit?

Select	Answer
A	Too little gain
B	Positive feedback
C	Nonlinear circuits or devices
D	Lack of neutralization

20. - E4E04

How can conducted and radiated noise caused by an automobile alternator be suppressed?

Select	Answer
A	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
B	By installing a noise suppression resistor and a blocking capacitor in both leads
C	By connecting the radio's power leads directly to the battery and by installing coaxial capacitors in line with the alternator leads
D	By installing a high-pass filter in series with the radio's power lead and a low-pass filter in parallel with the field lead

21. - E5A11

What is the half-power bandwidth of a 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

22. - E5B04

What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors, all in parallel?

Select	Answer
A	110 seconds
B	440 seconds
C	55 seconds
D	220 seconds

23. - E5C12

Which point on Figure E5-1 best represents the impedance of a series circuit consisting of a 300-ohm resistor and a 19-picofarad capacitor at 21.200 MHz?

Select	Answer
A	Point 3
B	Point 1
C	Point 7
D	Point 8

24. - E5D04

Why are short connections used at microwave frequencies?

Select	Answer
A	To reduce noise figure
B	To reduce phase shift along the connection
C	To increase compensating capacitance
D	To increase neutralizing resistance

25. - E6A04

What is the name given to an impurity atom that adds holes to a semiconductor crystal structure?

Select	Answer
A	Donor impurity
B	Insulator impurity
C	Acceptor impurity
D	N-type impurity

26. - E6B01

What is the most useful characteristic of a Zener diode?

Select	Answer
A	A constant voltage drop under conditions of varying current
B	A negative resistance region
C	An internal capacitance that varies with the applied voltage
D	A constant current drop under conditions of varying voltage

27. - E6C06

Why do CMOS digital integrated circuits have high immunity to noise on the input signal or power supply?

Select	Answer
A	Large bypass capacitance is inherent
B	Bandwidth is very limited
C	The input switching threshold is about two times the power supply voltage
D	The input switching threshold is about one-half the power supply voltage

28. - E6D05

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

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

29. - E6E12

Why are DIP through-hole package ICs not typically used at UHF and higher frequencies?

Select	Answer
A	Epoxy coating is conductive above 300 MHz
B	Too many pins
C	Excessive lead length
D	Unsuitable for combining analog and digital signals

30. - E6F04

What is the photovoltaic effect?

Select	Answer
A	The conversion of light to electrical energy
B	The conversion of voltage to current when exposed to light
C	The tendency of a battery to discharge when exposed to light
D	The conversion of electrical energy to mechanical energy

31. - E7A11

What type of logic defines "1" as a high voltage?

Select	Answer
A	Negative logic
B	Positive Logic
C	Assertive Logic
D	Reverse Logic

32. - E7B14

Why are switching amplifiers more efficient than linear amplifiers?

Select	Answer
A	Linear amplifiers have high gain resulting in higher harmonic content
B	Switching amplifiers operate at higher voltages
C	Switching amplifiers use push-pull circuits
D	The power transistor is at saturation or cutoff most of the time

33. - E7C06

What are the distinguishing features of an elliptical filter?

Select	Answer
A	Gradual passband rolloff with minimal stop band ripple
B	Gradual passband rolloff with extreme stop band ripple
C	Extremely flat response over its pass band with gradually rounded stop band corners
D	Extremely sharp cutoff with one or more notches in the stop band

34. - E7D15

What is the purpose of a step-start circuit in a high-voltage power supply?

Select	Answer
A	To allow for remote control of the power supply
B	To compensate for variations of the incoming line voltage
C	To allow the filter capacitors to charge gradually
D	To provide a dual-voltage output for reduced power applications

35. - E7E11

Which type of detector circuit is used for demodulating SSB signals?

Select	Answer
A	Phase comparator
B	Product detector
C	Discriminator
D	Phase detector

36. - E7F02

What kind of digital signal processing audio filter is used to remove unwanted noise from a received SSB signal?

Select	Answer
A	An adaptive filter
B	A phase-inverting filter
C	A Hilbert-transform filter
D	A crystal-lattice filter

37. - E7G03

What is the typical input impedance of an op-amp?

Select	Answer
A	100 ohms
B	Very high
C	1000 ohms
D	Very low

38. - E7H03

How is positive feedback supplied in a Hartley oscillator?

Select	Answer
A	Through a tapped coil
B	Through a capacitive divider
C	Through a neutralizing capacitor
D	Through link coupling

39. - E8A07

What determines the PEP-to-average power ratio of a single-sideband phone signal?

Select	Answer
A	Amplifier gain
B	Speech characteristics
C	The degree of carrier suppression
D	The frequency of the modulating signal

40. - E8B07

Orthogonal Frequency Division Multiplexing is a technique used for which type of amateur communication?

Select	Answer
A	OFDM signals are not allowed on amateur bands
B	High-speed digital modes
C	EME
D	Extremely low-power contacts

41. - E8C05

What is the approximate bandwidth of a 13-WPM International Morse Code transmission?

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

42. - E8D08

What parameter evaluates distortion of an AFSK signal caused by excessive input audio levels?

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

43. - E9A13

What term describes station output, taking into account all gains and losses?

Select	Answer
A	Effective radiated power
B	Half-power bandwidth
C	Apparent power
D	Power factor

44. - 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	75 degrees
C	25 degrees
D	7.5 degrees

45. - E9C08

What is a folded dipole antenna?

Select	Answer
A	A half-wave dipole with an additional parallel wire connecting its two ends
B	A dipole one-quarter wavelength long
C	A type of ground-plane antenna
D	A dipole configured to provide forward gain

46. - E9D02

How can linearly polarized Yagi antennas be used to produce circular polarization?

Select	Answer
A	Arrange two Yagis collinear to each other with the driven elements fed 180 degrees out of phase
B	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes

47. - E9E11

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

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

48. - E9F07

How does ladder line compare to small-diameter coaxial cable such as RG-58 at 50 MHz?

Select	Answer
A	Higher SWR
B	Lower loss
C	Smaller reflection coefficient
D	Lower velocity factor

49. - E9G04

What are the two families of circles and arcs that make up a Smith chart?

Select	Answer
A	Resistance and voltage
B	Voltage and impedance
C	Resistance and reactance
D	Reactance and voltage

50. - E9H10

How can the output voltage of a multiple-turn receiving loop antenna be increased?

Select	Answer
A	By utilizing high impedance wire for the coupling loop
B	By winding adjacent turns in opposing directions
C	By reducing the permeability of the loop shield
D	By increasing the number of turns and/or the area

Figure E5-1

Figure E9-2