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

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1. - E1A10

If an amateur station is installed aboard a ship or aircraft, what condition must be met before the station is operated?

Select	Answer
A	Its operation must be approved by the master of the ship or the pilot in command of the aircraft
B	The amateur station operator must agree not to transmit when the main radio of the ship or aircraft is in use
C	The amateur station must have a power supply that is completely independent of the main ship or aircraft power supply
D	The amateur operator must have an FCC Marine or Aircraft endorsement on his or her amateur license

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. - E1C07

What is meant by local control?

Select	Answer
A	Automatically manipulating local station controls
B	Direct manipulation of the transmitter by a control operator
C	Controlling a repeater using a portable handheld transceiver
D	Controlling a station through a local auxiliary link

4. - E1D07

Which amateur service HF bands have frequencies authorized for space stations?

Select	Answer
A	All HF bands
B	Only the 40 m, 30 m, 20 m, 15 m, 12 m and 10 m bands
C	Only the 40 m, 20 m, 17 m, 15 m and 10 m bands
D	Only the 40 m, 20 m, 17 m, 15 m, 12 m and 10 m bands

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

6. - E1F02

What privileges are authorized in the U.S. to persons holding an amateur service license granted by the Government of Canada?

Select	Answer
A	The operating terms and conditions of the Canadian amateur service license, not to exceed U.S. Extra Class privileges
B	All privileges of the Extra Class license
C	None, they must obtain a U.S. license
D	Full privileges, up to and including those of the Extra Class License, on the 80, 40, 20, 15, and 10 meter bands

7. - E2A08

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

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

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	180 or 360
C	60 or 100
D	128 or 256

9. - E2C09

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

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

10. - E2D08

What type of packet frame is used to transmit APRS beacon data?

Select	Answer
A	Connect
B	Disconnect
C	Acknowledgement
D	Unnumbered Information

11. - E2E02

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

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

12. - E3A12

What is the cause of auroral activity?

Select	Answer
A	The interaction in the E layer of charged particles from the Sun with the Earth's magnetic field
B	Meteor showers concentrated in the extreme northern and southern latitudes
C	A low sunspot level combined with tropospheric ducting
D	The interaction in the F2 layer between the solar wind and the Van Allen belt

13. - E3B12

What is the primary characteristic of chordal hop propagation?

Select	Answer
A	Successive ionospheric reflections without an intermediate reflection from the ground
B	Signals reflected back toward the transmitting station
C	Propagation across the geomagnetic equator
D	Propagation away from the great circle bearing between stations

14. - E3C15

What might a sudden rise in radio background noise indicate?

Select	Answer
A	Increased transequatorial propagation likely
B	A meteor ping
C	A solar flare has occurred
D	Long-path propagation is occurring

15. - E4A09

When using a computer's soundcard input to digitize signals, what is the highest frequency signal that can be digitized without aliasing?

Select	Answer
A	It depends on how the data is stored internally
B	The same as the sample rate
C	One-tenth the sample rate
D	One-half the sample rate

16. - E4B15

Which of the following can be used as a relative measurement of the Q for a series-tuned circuit?

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

17. - E4C01

What is an effect of excessive phase noise in the local oscillator section of a receiver?

Select	Answer
A	It decreases receiver third-order intermodulation distortion dynamic range
B	It can cause strong signals on nearby frequencies to interfere with reception of weak signals
C	It reduces receiver sensitivity
D	It limits the receiver's ability to receive strong signals

18. - E4D09

What is the purpose of the preselector in a communications receiver?

Select	Answer
A	To allow selection of the optimum RF amplifier device
B	To store often-used frequencies
C	To increase rejection of unwanted signals
D	To provide a range of AGC time constants

19. - E4E13

What might be the cause of a loud roaring or buzzing AC line interference that comes and goes at intervals?

Select	Answer
A	Arcing contacts in a thermostatically controlled device
B	A defective doorbell or doorbell transformer inside a nearby residence
C	All of these choices are correct
D	A malfunctioning illuminated advertising display

20. - E5A03

What is the magnitude of the impedance of a series RLC circuit at resonance?

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

21. - E5B06

What is susceptance?

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

22. - E5C09

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

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

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	1.42 mW
B	704 W
C	355 W
D	252 W

24. - E6A10

In Figure E6-2, what is the schematic symbol for an N-channel dual-gate MOSFET?

Select	Answer
A	2
B	6
C	5
D	4

25. - E6B12

What is one common use for PIN diodes?

Select	Answer
A	As a high voltage rectifier
B	As a constant current source
C	As an RF switch
D	As a constant voltage source

26. - E6C02

What happens when the level of a comparator's input signal crosses the threshold?

Select	Answer
A	The comparator changes its output state
B	The IC input can be damaged
C	The comparator enters latch-up
D	The feedback loop becomes unstable

27. - E6D03

Which of the following is an aspect of the piezoelectric effect?

Select	Answer
A	Generation of electrical energy in the presence of light
B	Mechanical deformation of material by the application of a magnetic field
C	Mechanical deformation of material by the application of a voltage
D	Increased conductivity in the presence of light

28. - E6E01

Which of the following is true of a charge-coupled device (CCD)?

Select	Answer
A	It is used in a battery charger circuit
B	It samples an analog signal and passes it in stages from the input to the output
C	It is a CMOS analog-to-digital converter
D	Its phase shift changes rapidly with frequency

29. - E6F12

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

Select	Answer
A	Protons
B	Photons
C	Holes
D	Electrons

30. - E7A09

What logical operation is performed by an exclusive NOR gate?

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

31. - E7B12

What type of amplifier circuit is shown in Figure E7-1?

Select	Answer
A	Common base
B	Emitter follower
C	Common collector
D	Common emitter

32. - E7C03

What advantage does a Pi-L-network have over a regular Pi-network for impedance matching between the final amplifier of a vacuum-tube transmitter and an antenna?

Select	Answer
A	Higher efficiency
B	Greater harmonic suppression
C	Lower losses
D	Greater transformation range

33. - E7D12

What is the drop-out voltage of an analog voltage regulator?

Select	Answer
A	Minimum input-to-output voltage required to maintain regulation
B	Maximum amount that the output voltage may decrease at rated load
C	Minimum input voltage for rated power dissipation
D	Maximum amount that the output voltage drops when the input voltage is varied over its specified range

34. - E7E09

What occurs when an excessive amount of signal energy reaches a mixer circuit?

Select	Answer
A	A beat frequency is generated
B	Automatic limiting occurs
C	Spurious mixer products are generated
D	Mixer blanking occurs

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	As an audio filter in a receiver
C	For smoothing power supply output
D	As a low-pass filter used between a transmitter and a transmission line

37. - E7H11

What are the major spectral impurity components of direct digital synthesizers?

Select	Answer
A	Nyquist limit noise
B	Spurious signals at discrete frequencies
C	Digital conversion noise
D	Broadband noise

38. - E8A10

What is the purpose of a low pass filter used in conjunction with a digital-to-analog converter?

Select	Answer
A	Improve accuracy by removing out of sequence codes from the input
B	All of these choices are correct
C	Lower the input bandwidth to increase the effective resolution
D	Remove harmonics from the output caused by the discrete analog levels generated

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

Select	Answer
A	A digital mode for narrow band, slow speed transmissions
B	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
C	A frequency modulation technique which uses non-harmonically related frequencies
D	A bandwidth compression technique using Fourier transforms

40. - E8C07

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

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

41. - E8D06

Which of the following indicates likely overmodulation of an AFSK signal such as PSK or MFSK?

Select	Answer
A	Strong ALC action
B	Rapid signal fading
C	High reflected power
D	Harmonics on higher bands

42. - E9A04

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

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

43. - E9B02

In the antenna radiation pattern shown in Figure E9-1, what is the front-to-back ratio?

Select	Answer
A	18 dB
B	14 dB
C	24 dB
D	36 dB

44. - E9C05

What is an OCFD antenna?

Select	Answer
A	A dipole feed approximately 1/3 the way from one end with a 4:1 balun to provide multiband operation
B	A remotely tunable dipole antenna using orthogonally controlled frequency diversity
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	An eight band dipole antenna using octophase filters

45. - E9D12

Which of the following would provide the best RF ground for your station?

Select	Answer
A	An electrically short connection to a metal water pipe
B	A 50 ohm resistor connected to ground
C	An electrically short connection to 3 or 4 interconnected ground rods via a series RF choke
D	An electrically short connection to 3 or 4 interconnected ground rods driven into the Earth

46. - E9E08

Which of the following measurements is characteristic of a mismatched transmission line?

Select	Answer
A	An SWR greater than 1:1
B	An SWR less than 1:1
C	A reflection coefficient greater than 1
D	A dielectric constant greater than 1

47. - E9F02

Which of the following determines the velocity factor of a transmission line?

Select	Answer
A	The termination impedance
B	Dielectric materials used in the line
C	The center conductor resistivity
D	The line length

48. - E9G07

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

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

49. - E9H08

What is the function of a sense antenna?

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

50. - E0A02

When evaluating RF exposure levels from your station at a neighbor's home, what must you do?

Select	Answer
A	Make sure signals from your station are less than the controlled MPE limits
B	You need only evaluate exposure levels on your own property
C	Make sure signals from your station are less than the uncontrolled MPE limits
D	Advise your neighbors of the results of your tests

Figure E6-2

Figure E7-1

Figure E9-1

Figure E9-3