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

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

2. - E1B03

Within what distance must an amateur station protect an FCC monitoring facility from harmful interference?

Select	Answer
A	10 miles
B	30 miles
C	1 mile
D	3 miles

3. - E1C12

What types of communications may be transmitted to amateur stations in foreign countries?

Select	Answer
A	Business-related messages for non-profit organizations
B	Messages intended for connection to users of the maritime satellite service
C	All of these choices are correct
D	Communications incidental to the purpose of the amateur service and remarks of a personal nature

4. - E1D02

What is the amateur satellite service?

Select	Answer
A	A radio communications service using amateur radio stations on satellites
B	A radio navigation service using satellites for the purpose of self training, intercommunication and technical studies carried out by amateurs
C	A radio communications service using stations on Earth satellites for public service broadcast
D	A spacecraft launching service for amateur-built satellites

5. - E1E03

What is a Volunteer Examiner Coordinator?

Select	Answer
A	A person who has volunteered to prepare amateur operator license examinations
B	An organization that has entered into an agreement with the FCC to coordinate amateur operator license examinations
C	A person who has volunteered to administer amateur operator license examinations
D	The person who has entered into an agreement with the FCC to be the VE session manager

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	222 MHz - 223 MHz
B	53 MHz - 54 MHz
C	440 MHz - 450 MHz
D	420 MHz - 430 MHz

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	435 MHz - 438 MHz
C	50.0 MHz - 50.2 MHz
D	144 MHz - 146 MHz

8. - E2B16

Which is a video standard used by North American Fast Scan ATV stations?

Select	Answer
A	NTSC
B	Scottie
C	DRM
D	PAL

9. - E2C04

What type of transmission is most often used for a ham radio mesh network?

Select	Answer
A	Frequency division multiplex in the 24 GHz band
B	Store and forward on the 440 MHz band
C	Spread spectrum in the 2.4 GHz band
D	Multiple Frequency Shift Keying in the 10 GHz band

10. - E2D12

How does JT65 improve EME communications?

Select	Answer
A	It can decode signals many dB below the noise floor using FEC
B	It controls the receiver to track Doppler shift
C	It supplies signals to guide the antenna to track the Moon
D	All of these choices are correct

11. - E2E07

What is the typical bandwidth of a properly modulated MFSK16 signal?

Select	Answer
A	2.16 kHz
B	550 Hz
C	31 Hz
D	316 Hz

12. - E3A03

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

Select	Answer
A	When the MUF is above 30 MHz
B	When the Moon is at perigee
C	When the Moon is full
D	When the Moon is at apogee

13. - E3B02

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

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

14. - E3C10

What does the 304A solar parameter measure?

Select	Answer
A	The solar emission at 304 GHz, correlated to X-Ray flare levels
B	UV emissions at 304 angstroms, correlated to solar flux index
C	The ratio of X-Ray flux to radio flux, correlated to sunspot number
D	The solar wind velocity at 304 degrees from the solar equator, correlated to solar activity

15. - E4A12

Which of the following procedures is an important precaution to follow when connecting a spectrum analyzer to a transmitter output?

Select	Answer
A	All of these choices are correct
B	Match the antenna to the load
C	Use high quality double shielded coaxial cables to reduce signal losses
D	Attenuate the transmitter output going to the spectrum analyzer

16. - E4B04

If a frequency counter with a specified accuracy of +/- 0.1 ppm reads 146,520,000 Hz, what is the most the actual frequency being measured could differ from the reading?

Select	Answer
A	0.1 MHz
B	14.652 Hz
C	1.4652 Hz
D	1.4652 kHz

17. - E4C09

Which of the following choices is a good reason for selecting a high frequency for the design of the IF in a conventional HF or VHF communications receiver?

Select	Answer
A	Improved receiver noise figure
B	Fewer components in the receiver
C	Reduced drift
D	Easier for front-end circuitry to eliminate image responses

18. - E4D12

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

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

19. - E4E12

What is one disadvantage of using some types of automatic DSP notch-filters when attempting to copy CW signals?

Select	Answer
A	Ringing in the DSP filter will completely remove the spaces between the CW characters
B	Any nearby signal passing through the DSP system will overwhelm the desired signal
C	A DSP filter can remove the desired signal at the same time as it removes interfering signals
D	Received CW signals will appear to be modulated at the DSP clock frequency

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

21. - E5B02

What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial voltage?

Select	Answer
A	One discharge period
B	A discharge factor of one
C	An exponential discharge rate of one
D	One time constant

22. - E5C04

Which of the following represents a capacitive reactance in polar coordinates?

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

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	0.5
B	1.414
C	0.866
D	1.73

24. - E6A05

What is the alpha of a bipolar junction transistor?

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

25. - E6B08

Which of the following describes a type of semiconductor diode?

Select	Answer
A	CMOS-field effect
B	Metal-semiconductor junction
C	Thermionic emission diode
D	Electrolytic rectifier

26. - E6C07

What best describes a pull-up or pull-down resistor?

Select	Answer
A	A resistor connected to an op-amp output that only functions when the logic output is false
B	A resistor in a keying circuit used to reduce key clicks
C	A resistor that insures that an oscillator frequency does not drive lower over time
D	A resistor connected to the positive or negative supply line used to establish a voltage when an input or output is an open circuit

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

28. - E6E04

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

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

29. - E6F07

What is a solid state relay?

Select	Answer
A	A mechanical relay that latches in the on or off state each time it is pulsed
B	A relay using transistors to drive the relay coil
C	A device that uses semiconductors to implement the functions of an electromechanical relay
D	A passive delay line

30. - E7A05

Which of the following is a circuit that continuously alternates between two states without an external clock?

Select	Answer
A	J-K flip-flop
B	Astable multivibrator
C	T flip-flop
D	Monostable multivibrator

31. - E7B15

What is one way to prevent thermal runaway in a bipolar transistor amplifier?

Select	Answer
A	Neutralization
B	All of these choices are correct
C	Select transistors with high beta
D	Use a resistor in series with the emitter

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

33. - E7D06

What is the purpose of Q1 in the circuit shown in Figure E7-3?

Select	Answer
A	It provides a constant load for the voltage source
B	It provides D1 with current
C	It provides negative feedback to improve regulation
D	It increases the current-handling capability of the regulator

34. - E7E08

What are the principal frequencies that appear at the output of a mixer circuit?

Select	Answer
A	The two input frequencies along with their sum and difference frequencies
B	1.414 and 0.707 times the input frequency
C	The sum, difference and square root of the input frequencies
D	Two and four times the original frequency

35. - E7F04

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

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

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a high-pass filter used to block RFI at the input to receivers
B	For smoothing power supply output
C	As a low-pass filter used between a transmitter and a transmission line
D	As an audio filter in a receiver

37. - E7H07

How can an oscillator's microphonic responses be reduced?

Select	Answer
A	Use of NP0 capacitors
B	Mechanically isolating the oscillator circuitry from its enclosure
C	Eliminating noise on the oscillator's power supply
D	Using the oscillator only for CW and digital signals

38. - E8A01

What is the name of the process that shows that a square wave is made up of a sine wave plus all of its odd harmonics?

Select	Answer
A	Differential analysis
B	Fourier analysis
C	Vector analysis
D	Numerical analysis

39. - E8B06

What is the deviation ratio of an FM-phone signal having a maximum frequency swing of plus or minus 7.5 kHz when the maximum modulation frequency is 3.5 kHz?

Select	Answer
A	47
B	0.214
C	0.47
D	2.14

40. - E8C03

When performing phase shift keying, why is it advantageous to shift phase precisely at the zero crossing of the RF carrier?

Select	Answer
A	It improves carrier suppression
B	This results in the least possible transmitted bandwidth for the particular mode
C	All of these choices are correct
D	It is easier to demodulate with a conventional, non-synchronous detector

41. - E8D09

What is considered a good minimum IMD level for an idling PSK signal?

Select	Answer
A	+10 dB
B	-30 dB
C	+15 dB
D	-20 dB

42. - E9A04

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

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

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

44. - E9C01

What is the radiation pattern of two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?

Select	Answer
A	A figure-8 oriented along the axis of the array
B	Omni-directional
C	Cardioid
D	A figure-8 broadside to the axis of the array

45. - E9D03

Where should a high Q loading coil be placed to minimize losses in a shortened vertical antenna?

Select	Answer
A	As close to the transmitter as possible
B	At a voltage node
C	Near the center of the vertical radiator
D	As low as possible on the vertical radiator

46. - E9E12

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

Select	Answer
A	It prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
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 ensures that each driven element operates in concert with the others to create the desired antenna pattern

47. - E9F15

What impedance does a 1/2 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	The same as the characteristic impedance of the line
B	Very low impedance
C	The same as the output impedance of the generator
D	Very high impedance

48. - E9G04

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

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

49. - E9H01

When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?

Select	Answer
A	Its overall length must not exceed 1/4 wavelength
B	It should be one or more wavelengths long
C	It must be mounted more than 1 wavelength above ground
D	It should be configured as a four-sided loop

50. - E0A05

What is one of the potential hazards of using microwaves in the amateur radio bands?

Select	Answer
A	The high gain antennas commonly used can result in high exposure levels
B	Microwaves often travel long distances by ionospheric reflection
C	Microwaves are ionizing radiation
D	The extremely high frequency energy can damage the joints of antenna structures

Figure E7-3