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

2. - E1B04

What must be done before placing an amateur station within an officially designated wilderness area or wildlife preserve, or an area listed in the National Register of Historical Places?

Select	Answer
A	An Environmental Assessment must be submitted to the FCC
B	A proposal must be submitted to the National Park Service
C	A form FSD-15 must be submitted to the Department of the Interior
D	A letter of intent must be filed with the National Audubon Society

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	The U.S. embassy must approve of your operation
B	You must identify in the official language of the country in which you are operating
C	You must append "/CEPT" to your call sign
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	6 meters and 2 meters
B	6 meters, 2 meters, and 1.25 meters
C	2 meters and 1.25 meters
D	2 meters

5. - E1E02

Where are the questions for all written U.S. amateur license examinations listed?

Select	Answer
A	In the appropriate FCC Report and Order
B	In FCC Part 97
C	In a question pool maintained by all the VECs
D	In a question pool maintained by the FCC

6. - E1F03

Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?

Select	Answer
A	The equipment dealer assembled it from a kit
B	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
C	It was imported from a manufacturer in another country and was certificated by that country's government
D	It was purchased in used condition from an amateur operator and is sold to another amateur operator for use at that operator's station

7. - E2A08

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

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

8. - E2B01

How many times per second is a new frame transmitted in a fast-scan (NTSC) television system?

Select	Answer
A	30
B	60
C	120
D	90

9. - E2C07

What is the Cabrillo format?

Select	Answer
A	The rules of order for meetings between contest sponsors
B	A standard for submission of electronic contest logs
C	The most common set of contest rules
D	A method of exchanging information during a contest QSO

10. - E2D10

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

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

11. - E2E08

Which of the following HF digital modes can be used to transfer binary files?

Select	Answer
A	PACTOR
B	Hellschreiber
C	AMTOR
D	RTTY

12. - E3A13

Which emission mode is best for aurora propagation?

Select	Answer
A	CW
B	FM
C	SSB
D	RTTY

13. - E3B14

What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?

Select	Answer
A	They are bent toward the magnetic poles
B	Their polarization is randomly modified
C	They become phase-locked
D	They become elliptically polarized

14. - E3C11

What does VOACAP software model?

Select	Answer
A	VHF radio propagation
B	AC current and impedance
C	AC voltage and impedance
D	HF propagation

15. - E4A02

Which of the following parameters would a spectrum analyzer display on the vertical and horizontal axes?

Select	Answer
A	SWR and time
B	SWR and frequency
C	RF amplitude and time
D	RF amplitude and frequency

16. - E4B13

Which S parameter is equivalent to forward gain?

Select	Answer
A	S12
B	S22
C	S21
D	S11

17. - E4C01

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

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

18. - E4D12

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

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

19. - E4E04

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

Select	Answer
A	By installing a noise suppression resistor and a blocking capacitor in both leads
B	By installing filter capacitors in series with the DC power lead and a blocking capacitor in the field lead
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

20. - E5A09

How is the Q of an RLC parallel resonant circuit calculated?

Select	Answer
A	Resistance divided by the reactance of either the inductance or capacitance
B	Reactance of the inductance multiplied by the reactance of the capacitance
C	Reactance of either the inductance or capacitance multiplied by the resistance
D	Reactance of either the inductance or capacitance divided by the resistance

21. - 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	55 seconds
B	440 seconds
C	220 seconds
D	110 seconds

22. - E5C13

What coordinate system is often used to display the resistive, inductive, and/or capacitive reactance components of impedance?

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

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	704 W
B	355 W
C	1.42 mW
D	252 W

24. - E6A11

In Figure E6-2, what is the schematic symbol for a P-channel junction FET?

Select	Answer
A	6
B	3
C	1
D	2

25. - E6B05

What characteristic of a PIN diode makes it useful as an RF switch or attenuator?

Select	Answer
A	Reverse bias controls its forward voltage drop
B	Ability to dissipate large amounts of power
C	Extremely high reverse breakdown voltage
D	A large region of intrinsic material

26. - E6C13

Which of the following is an advantage of BiCMOS logic?

Select	Answer
A	Its simplicity results in much less expensive devices than standard CMOS
B	All of these choices are correct
C	It has the high input impedance of CMOS and the low output impedance of bipolar transistors
D	It is totally immune to electrostatic damage

27. - E6D16

What is the common name for a capacitor connected across a transformer secondary that is used to absorb transient voltage spikes?

Select	Answer
A	Trimmer capacitor
B	Clipper capacitor
C	Snubber capacitor
D	Feedback capacitor

28. - E6E03

Which of the following materials is likely to provide the highest frequency of operation when used in MMICs?

Select	Answer
A	Silicon dioxide
B	Silicon nitride
C	Gallium nitride
D	Silicon

29. - E6F09

What is the efficiency of a photovoltaic cell?

Select	Answer
A	The effective payback period
B	The output RF power divided by the input DC power
C	The open-circuit voltage divided by the short-circuit current under full illumination
D	The relative fraction of light that is converted to current

30. - E7A10

What is a truth table?

Select	Answer
A	A list of inputs and corresponding outputs for a digital device
B	A table of logic symbols that indicate the logic states of an op-amp
C	A table of logic symbols that indicate the high logic states of an op-amp
D	A diagram showing logic states when the digital device output is true

31. - E7B15

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

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

32. - E7C07

What kind of filter would you use to attenuate an interfering carrier signal while receiving an SSB transmission?

Select	Answer
A	A notch filter
B	A band-pass filter
C	A Pi-network filter
D	An all-pass filter

33. - E7D07

What is the purpose of C2 in the circuit shown in Figure E7-3?

Select	Answer
A	To provide fixed DC bias for Q1
B	It bypasses hum around D1
C	It is a brute force filter for the output
D	To self-resonate at the hum frequency

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 unmodulated bandwidth of the transmitted signal
C	The frequency components present in the modulating signal
D	The lowest frequency band that the transmitter or receiver covers

35. - E7F02

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

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

36. - E7G07

What magnitude of voltage gain can be expected from the circuit in Figure E7-4 when R1 is 10 ohms and RF is 470 ohms?

Select	Answer
A	24
B	0.21
C	47
D	94

37. - E7H11

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

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

38. - E8A10

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

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

39. - E8B10

What describes frequency division multiplexing?

Select	Answer
A	The transmitted signal jumps from band to band at a predetermined rate
B	Two or more information streams are merged into a digital combiner, which then pulse position modulates the transmitter
C	Two or more information streams are merged into a baseband, which then modulates the transmitter
D	The transmitted signal is divided into packets of information

40. - E8C09

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

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

41. - E8D01

Why are received spread spectrum signals resistant to interference?

Select	Answer
A	The receiver is always equipped with a digital blanker
B	If interference is detected by the receiver it will signal the transmitter to change frequencies
C	The high power used by a spread spectrum transmitter keeps its signal from being easily overpowered
D	Signals not using the spread spectrum algorithm are suppressed in the receiver

42. - E9A07

What is meant by antenna gain?

Select	Answer
A	The ratio of the amount of power radiated by an antenna compared to the transmitter output power
B	The final amplifier gain minus the transmission line losses
C	The ratio of the radiated signal strength of an antenna in the direction of maximum radiation to that of a reference antenna
D	The ratio of the signal in the forward direction to that in the opposite direction

43. - E9B05

What type of antenna pattern over real ground is shown in Figure E9-2?

Select	Answer
A	Radiation resistance
B	Polarization
C	Elevation
D	Azimuth

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

45. - E9D09

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

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

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 prevents reflected power from traveling back down the feed line and causing harmonic radiation from the transmitter
C	It makes sure the antenna has a low-angle radiation pattern
D	It allows single-band antennas to operate on other bands

47. - E9F04

What is the typical velocity factor for a coaxial cable with solid polyethylene dielectric?

Select	Answer
A	0.66
B	0.30
C	0.10
D	2.70

48. - E9G07

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

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

49. - E9H06

What is the triangulation method of direction finding?

Select	Answer
A	A fixed receiving station plots three headings to the signal source
B	Antenna headings from several different receiving locations are used to locate the signal source
C	The geometric angles of sky waves from the source are used to determine its position
D	A fixed receiving station uses three different antennas to plot the location of the signal source

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

Figure E6-2

Figure E7-3

Figure E7-4

Figure E9-2

Figure E9-3