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

2. - E1B08

What limitations may the FCC place on an amateur station if its signal causes interference to domestic broadcast reception, assuming that the receivers involved are of good engineering design?

Select	Answer
A	The amateur station must cease operation
B	The amateur station must cease operation on all frequencies below 30 MHz
C	The amateur station must cease operation on all frequencies above 30 MHz
D	The amateur station must avoid transmitting during certain hours on frequencies that cause the interference

3. - E1C09

Which of these ranges of frequencies is available for an automatically controlled repeater operating below 30 MHz?

Select	Answer
A	18.110 MHz - 18.168 MHz
B	24.940 MHz - 24.990 MHz
C	29.500 MHz - 29.700 MHz
D	10.100 MHz - 10.150 MHz

4. - E1D01

What is the definition of the term telemetry?

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

5. - E1E08

To which of the following examinees may a VE not administer an examination?

Select	Answer
A	All of these choices are correct
B	Relatives of the VE as listed in the FCC rules
C	Friends of the VE
D	Employees of the VE

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 produce full legal output when driven by not more than 5 watts of mean RF input power
B	It must exhibit a gain of 0 dB or less over its full output range
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 be capable of external RF switching between its input and output networks

7. - E2A02

What is the direction of a descending pass for an amateur satellite?

Select	Answer
A	From north to south
B	From west to east
C	From south to north
D	From east to west

8. - E2B15

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

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

9. - E2C08

Which of the following contacts may be confirmed through the U.S. QSL bureau system?

Select	Answer
A	Contacts using tactical call signs
B	Repeater contacts between U.S. club members
C	Special event contacts between stations in the U.S.
D	Contacts between a U.S. station and a non-U.S. station

10. - E2D11

Which of the following data are used by the APRS network to communicate your location?

Select	Answer
A	Latitude and longitude
B	Polar coordinates
C	Radio direction finding spectrum analysis
D	Time and frequency

11. - E2E13

Which of the following is a possible reason that attempts to initiate contact with a digital station on a clear frequency are unsuccessful?

Select	Answer
A	Your transmit frequency is incorrect
B	The protocol version you are using is not the supported by the digital station
C	Another station you are unable to hear is using the frequency
D	All of these choices are correct

12. - E3A10

Which type of atmospheric structure can create a path for microwave propagation?

Select	Answer
A	Dust devil
B	The jet stream
C	Wind shear
D	Temperature inversion

13. - E3B08

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

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

14. - E3C03

Which of the following signal paths is most likely to experience high levels of absorption when the A index or K index is elevated?

Select	Answer
A	NVIS
B	Polar paths
C	Sporadic-E
D	Transequatorial propagation

15. - E4A06

What is the effect of aliasing in a digital or computer-based oscilloscope?

Select	Answer
A	False signals are displayed
B	All signals will have a DC offset
C	Calibration of the vertical scale is no longer valid
D	False triggering occurs

16. - E4B08

Which of the following is a characteristic of a good DC voltmeter?

Select	Answer
A	Low reluctance input
B	High reluctance input
C	Low impedance input
D	High impedance input

17. - E4C17

Which of the following has the largest effect on an SDR receiver's linearity?

Select	Answer
A	Analog-to-digital converter sample width in bits
B	CPU register width in bits
C	RAM speed used for data storage
D	Anti-aliasing input filter bandwidth

18. - E4D14

Which of the following is a way to reduce the likelihood of receiver desensitization?

Select	Answer
A	Increase the receiver front end gain
B	Decrease the RF bandwidth of the receiver
C	Switch from fast AGC to slow AGC
D	Raise the receiver IF frequency

19. - E4E06

What is a major cause of atmospheric static?

Select	Answer
A	Thunderstorms
B	Geomagnetic storms
C	Solar radio frequency emissions
D	Meteor showers

20. - E5A16

What is the resonant frequency of a parallel RLC circuit if R is 33 ohms, L is 50 microhenrys and C is 10 picofarads?

Select	Answer
A	7.12 kHz
B	23.5 kHz
C	23.5 MHz
D	7.12 MHz

21. - E5B06

What is susceptance?

Select	Answer
A	The magnetic impedance of a circuit
B	The inverse of reactance
C	A measure of the efficiency of a transformer
D	The ratio of magnetic field to electric field

22. - E5C08

What coordinate system is often used to display the phase angle of a circuit containing resistance, inductive and/or capacitive reactance?

Select	Answer
A	Polar coordinates
B	Maidenhead grid
C	Elliptical coordinates
D	Faraday grid

23. - E5D14

What is reactive power?

Select	Answer
A	Power consumed in wire resistance in an inductor
B	Power consumed in circuit Q
C	Wattless, nonproductive power
D	Power lost because of capacitor leakage

24. - E6A01

In what application is gallium arsenide used as a semiconductor material in preference to germanium or silicon?

Select	Answer
A	In high-power audio circuits
B	In very low frequency RF circuits
C	In high-current rectifier circuits
D	In microwave circuits

25. - E6B08

Which of the following describes a type of semiconductor diode?

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

26. - E6C06

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

Select	Answer
A	Input signals are stronger
B	The input switching threshold is about one-half the power supply voltage
C	Larger bypass capacitors are used in CMOS circuit design
D	The input switching threshold is about two times the power supply voltage

27. - E6D11

How many turns will be required to produce a 1-mH inductor using a core that has an inductance index (A L) value of 523 millihenrys/1000 turns?

Select	Answer
A	4 turns
B	229 turns
C	2 turns
D	43 turns

28. - E6E07

Which of the following is typically used to construct a MMIC-based microwave amplifier?

Select	Answer
A	Microstrip construction
B	Ground-plane construction
C	Wave-soldering construction
D	Point-to-point construction

29. - E6F12

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

Select	Answer
A	Photons
B	Holes
C	Electrons
D	Protons

30. - E7A01

Which is a bi-stable circuit?

Select	Answer
A	An "OR" gate
B	A flip-flop
C	An "AND" gate
D	A clock

31. - E7B05

What can be done to prevent unwanted oscillations in an RF power amplifier?

Select	Answer
A	Tune the stage for maximum SWR
B	Use a phase inverter in the output filter
C	Tune both the input and output for maximum power
D	Install parasitic suppressors and/or neutralize the stage

32. - E7C11

Which of the following is the common name for a filter network which is equivalent to two L-networks connected back-to-back with the two inductors in series and the capacitors in shunt at the input and output?

Select	Answer
A	Pi-L
B	Pi
C	Cascode
D	Omega

33. - E7D11

What circuit element is controlled by a series analog voltage regulator to maintain a constant output voltage?

Select	Answer
A	Pass transistor
B	Switching inductance
C	Reference voltage
D	Error amplifier

34. - E7E07

What is meant by the term baseband in radio communications?

Select	Answer
A	The basic oscillator frequency in an FM transmitter that is multiplied to increase the deviation and carrier frequency
B	The frequency components present in the modulating signal
C	The unmodulated bandwidth of the transmitted signal
D	The lowest frequency band that the transmitter or receiver covers

35. - E7F01

What is meant by direct digital conversion as applied to software defined radios?

Select	Answer
A	A switching mixer is used to generate I and Q signals directly from the RF input
B	Incoming RF is converted to a control voltage for a voltage controlled oscillator
C	Incoming RF is digitized by an analog-to-digital converter without being mixed with a local oscillator signal
D	Software is converted from source code to object code during operation of the receiver

36. - E7G10

What absolute voltage gain can be expected from the circuit in Figure E7-4 when R1 is 1800 ohms and RF is 68 kilohms?

Select	Answer
A	1
B	38
C	0.03
D	76

37. - E7H06

Which of the following oscillator circuits are commonly used in VFOs?

Select	Answer
A	Armstrong and deForest
B	Pierce and Zener
C	Colpitts and Hartley
D	Negative feedback and balanced feedback

38. - E8A09

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

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

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	2000
B	3
C	1/3
D	6000

40. - E8C07

What is the necessary bandwidth of a 4800-Hz frequency shift, 9600-baud ASCII FM transmission?

Select	Answer
A	15.36 kHz
B	4.8 kHz
C	9.6 kHz
D	5.76 kHz

41. - E8D02

What spread spectrum communications technique uses a high speed binary bit stream to shift the phase of an RF carrier?

Select	Answer
A	Direct sequence
B	Frequency hopping
C	Binary phase-shift keying
D	Phase compandored spread spectrum

42. - E9A11

Which of the following factors determines ground losses for a ground-mounted vertical antenna operating in the 3 MHz to 30 MHz range?

Select	Answer
A	Take-off angle
B	Soil conductivity
C	The standing wave ratio
D	Distance from the transmitter

43. - E9B11

What is a disadvantage of decreasing the number of wire segments in an antenna model below the guideline of 10 segments per half-wavelength?

Select	Answer
A	The resulting design will favor radiation of harmonic energy
B	The computed feed point impedance may be incorrect
C	The antenna will become mechanically unstable
D	Ground conductivity will not be accurately modeled

44. - E9C02

What is the radiation pattern of two 1/4 wavelength vertical antennas spaced 1/4 wavelength apart and fed 90 degrees out of phase?

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

45. - E9D07

What is an advantage of using top loading in a shortened HF vertical antenna?

Select	Answer
A	Higher losses
B	Improved radiation efficiency
C	Lower Q
D	Greater structural strength

46. - E9E06

What is the equivalent lumped-constant network for a hairpin matching system of a 3-element Yagi?

Select	Answer
A	A series capacitor
B	Pi-L-network
C	A shunt inductor
D	Pi-network

47. - E9F08

What is the term for the ratio of the actual speed at which a signal travels through a transmission line to the speed of light in a vacuum?

Select	Answer
A	Velocity factor
B	Surge impedance
C	Characteristic impedance
D	Standing wave ratio

48. - E9G01

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

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

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	They must be erected at least 1/2 wavelength above the ground to attain good directivity
C	Low loss coax transmission line is essential for good performance
D	Atmospheric noise is so high that gain over a dipole is not important

50. - E0A08

What does SAR measure?

Select	Answer
A	The rate of RF energy reflected from stationary terrain
B	Signal Amplification Rating
C	The rate at which RF energy is absorbed by the body
D	Synthetic Aperture Ratio of the human body

Figure E7-4