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

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1. - E1A12

With your transceiver displaying the carrier frequency of CW signals, you hear a DX station's CQ on 3.500 MHz. Is it legal to return the call using CW on the same frequency?

Select	Answer
A	No, one of the sidebands of the CW signal will be out of the band
B	Yes, the DX station initiated the contact
C	No, U.S. stations are not permitted to use CW emissions below 3.525 MHz
D	Yes, the displayed frequency is within the 80 meter CW band segment

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

3. - E1C01

What is a remotely controlled station?

Select	Answer
A	A station controlled indirectly through a control link
B	A station operated away from its regular home location
C	A station operating under automatic control
D	A station controlled by someone other than the licensee

4. - E1D06

Which of the following is a requirement of a space station?

Select	Answer
A	All of these choices are correct
B	The space station must be capable of terminating transmissions by telecommand when directed by the FCC
C	The space station must cease all transmissions after 5 years
D	The space station must be capable of changing its orbit whenever such a change is ordered by NASA

5. - E1E02

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

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

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	It was imported from a manufacturer in a country that does not require certification of RF power amplifiers
B	It was imported from a manufacturer in another country and was certificated by that country's government
C	The equipment dealer assembled it from a kit
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 prevent the satellite from emitting out-of-band signals
B	To avoid interfering with terrestrial QSOs
C	To prevent creating errors in the satellite telemetry
D	To avoid reducing the downlink power to all other users

8. - E2B08

Which of the following is a common method of transmitting accompanying audio with amateur fast-scan television?

Select	Answer
A	Frequency modulation of the video carrier
B	All of these choices are correct
C	Frequency-modulated sub-carrier
D	A separate VHF or UHF audio link

9. - E2C06

During a VHF/UHF contest, in which band segment would you expect to find the highest level of activity?

Select	Answer
A	In the middle of each band, usually on the national calling frequency
B	At the top of each band, usually in a segment reserved for contests
C	In the weak signal segment of the band, with most of the activity near the calling frequency
D	In the middle of the band, usually 25 kHz above the national calling frequency

10. - E2D14

What is one advantage of using JT65 coding?

Select	Answer
A	The ability to decode signals which have a very low signal to noise ratio
B	Easily copied by ear if necessary
C	Permits fast-scan TV transmissions over narrow bandwidth
D	Uses only a 65 Hz bandwidth

11. - E2E01

Which type of modulation is common for data emissions below 30 MHz?

Select	Answer
A	DTMF tones modulating an FM signal
B	Spread spectrum
C	Pulse modulation
D	FSK

12. - E3A05

Tropospheric propagation of microwave signals often occurs along what weather related structure?

Select	Answer
A	Warm and cold fronts
B	Sprites and jets
C	Gray-line
D	Lightning discharges

13. - E3B04

What is meant by the terms extraordinary and ordinary waves?

Select	Answer
A	Independent waves created in the ionosphere that are elliptically polarized
B	Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
C	Long path and short path waves
D	Refracted rays and reflected waves

14. - E3C06

By how much does the VHF/UHF radio horizon distance exceed the geometric horizon?

Select	Answer
A	By approximately 15 percent of the distance
B	By approximately four times the distance
C	By approximately 50 percent of the distance
D	By approximately twice the distance

15. - E4A14

What is the purpose of the prescaler function on a frequency counter?

Select	Answer
A	It amplifies low level signals for more accurate counting
B	It divides a higher frequency signal so a low-frequency counter can display the input frequency
C	It prevents oscillation in a low-frequency counter circuit
D	It multiplies a higher frequency signal so a low-frequency counter can display the operating frequency

16. - E4B07

What do the subscripts of S parameters represent?

Select	Answer
A	The relative time between measurements
B	Frequency order of the measurements
C	Relative quality of the data
D	The port or ports at which measurements are made

17. - E4C13

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

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

18. - E4D09

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

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

19. - E4E03

Which of the following signals might a receiver noise blanker be able to remove from desired signals?

Select	Answer
A	Signals which appear at one IF but not another
B	Signals which appear across a wide bandwidth
C	Signals which are constant at all IF levels
D	Signals which have a sharply peaked frequency distribution

20. - E5A11

What is the half-power bandwidth of a parallel 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

21. - E5B12

What is admittance?

Select	Answer
A	The term for the gain of a field effect transistor
B	The turns ratio of a transformer
C	The unit used for Q factor
D	The inverse of impedance

22. - E5C15

Which point in Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and an 18 microhenry inductor at 3.505 MHz?

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

23. - E5D16

What is the power factor of an R-L circuit having a 30 degree phase angle between the voltage and the current?

Select	Answer
A	0.577
B	0.5
C	1.73
D	0.866

24. - E6A07

Which of the following indicates that a silicon NPN junction transistor is biased on?

Select	Answer
A	Base-to-emitter voltage of approximately 6 to 7 volts
B	Base-to-emitter resistance of approximately 6 to 7 ohms
C	Base-to-emitter resistance of approximately 0.6 to 0.7 ohms
D	Base-to-emitter voltage of approximately 0.6 to 0.7 volts

25. - E6B12

What is one common use for PIN diodes?

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

26. - E6C12

What is BiCMOS logic?

Select	Answer
A	A logic device with two CMOS circuits per package
B	A FET logic family based on bimetallic semiconductors
C	An integrated circuit logic family using both bipolar and CMOS transistors
D	A logic family based on bismuth CMOS devices

27. - E6D14

Which type of slug material decreases inductance when inserted into a coil?

Select	Answer
A	Ferrite
B	Brass
C	Ceramic
D	Powdered-iron

28. - E6E09

Which of the following component package types would be most suitable for use at frequencies above the HF range?

Select	Answer
A	Radial lead
B	Axial lead
C	TO-220
D	Surface mount

29. - E6F12

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

Select	Answer
A	Protons
B	Photons
C	Holes
D	Electrons

30. - E7A11

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

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

31. - E7B05

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

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

32. - E7C12

Which describes a Pi-L-network used for matching a vacuum tube final amplifier to a 50 ohm unbalanced output?

Select	Answer
A	A Pi-network with an additional series inductor on the output
B	A Phase Inverter Load network
C	A network with only three discrete parts
D	A matching network in which all components are isolated from ground

33. - E7D15

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

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

34. - E7E04

What is one way a single-sideband phone signal can be generated?

Select	Answer
A	By driving a product detector with a DSB signal
B	By using a balanced modulator followed by a filter
C	By using a reactance modulator followed by a mixer
D	By using a loop modulator followed by a mixer

35. - E7F10

What aspect of receiver analog-to-digital conversion determines the maximum receive bandwidth of a Direct Digital Conversion SDR?

Select	Answer
A	Processor latency
B	Sample rate
C	Sample clock phase noise
D	Sample width in bits

36. - E7G03

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

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

37. - E7H01

What are three oscillator circuits used in Amateur Radio equipment?

Select	Answer
A	Taft, Hartley and Pierce
B	Pierce, Fenner and Beane
C	Colpitts, Hartley and Pierce
D	Taft, Pierce and negative feedback

38. - E8A04

What is "dither" with respect to analog to digital converters?

Select	Answer
A	A method of decimation by randomly skipping samples
B	A small amount of noise added to the input signal to allow more precise representation of a signal over time
C	An error caused by irregular quantization step size
D	An abnormal condition where the converter cannot settle on a value to represent the signal

39. - E8B10

What describes frequency division multiplexing?

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

40. - E8C08

How does ARQ accomplish error correction?

Select	Answer
A	Special binary codes provide automatic correction
B	If errors are detected, redundant data is substituted
C	Special polynomial codes provide automatic correction
D	If errors are detected, a retransmission is requested

41. - E8D09

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

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

42. - E9A15

What is the effective radiated power relative to a dipole of a repeater station with 150 watts transmitter power output, 2 dB feed line loss, 2.2 dB duplexer loss, and 7 dBd antenna gain?

Select	Answer
A	1977 watts
B	78.7 watts
C	286 watts
D	420 watts

43. - E9B08

How can the approximate beam-width in a given plane of a directional antenna be determined?

Select	Answer
A	Note the two points where the signal strength of the antenna is 3 dB less than maximum and compute the angular difference
B	Measure the ratio of the signal strengths of the radiated power lobes from the front and side of the antenna
C	Draw two imaginary lines through the ends of the elements and measure the angle between the lines
D	Measure the ratio of the signal strengths of the radiated power lobes from the front and rear of the antenna

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	An eight band dipole antenna using octophase filters
C	A multiband dipole antenna using one-way circular polarization for frequency diversity
D	A remotely tunable dipole antenna using orthogonally controlled frequency diversity

45. - 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	Stack two Yagis fed in phase to form an array with the respective elements in parallel planes
C	Stack two Yagis fed 90 degrees out of phase to form an array with the respective elements in parallel planes
D	Arrange two Yagis perpendicular to each other with the driven elements at the same point on the boom fed 90 degrees out of phase

46. - E9E07

What term best describes the interactions at the load end of a mismatched transmission line?

Select	Answer
A	Velocity factor
B	Dielectric constant
C	Reflection coefficient
D	Characteristic impedance

47. - E9F14

What impedance does a 1/2 wavelength transmission line present to a generator when the line is shorted 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. - E9G02

What type of coordinate system is used in a Smith chart?

Select	Answer
A	Resistance circles and reactance arcs
B	Resistance lines and reactance chords
C	Voltage circles and current arcs
D	Voltage lines and current chords

49. - E9H10

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

Select	Answer
A	By reducing the permeability of the loop shield
B	By increasing the number of wire turns in the loop and reducing the area of the loop structure
C	By winding adjacent turns in opposing directions
D	By increasing either the number of wire turns in the loop or the area of the loop structure or both

50. - E0A08

What does SAR measure?

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

Figure E5-2