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

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1. - E1A01

When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the highest frequency at which a properly adjusted USB emission will be totally within the band?

Select	Answer
A	1 kHz below the upper band edge
B	The exact upper band edge
C	3 kHz below the upper band edge
D	300 Hz below the upper band edge

2. - E1B05

What is the National Radio Quiet Zone?

Select	Answer
A	An area in New Mexico surrounding the White Sands Test Area
B	An area in Florida surrounding Cape Canaveral
C	An area surrounding the National Radio Astronomy Observatory
D	An area in Puerto Rico surrounding the Arecibo Radio Telescope

3. - E1C08

What is the maximum permissible duration of a remotely controlled station's transmissions if its control link malfunctions?

Select	Answer
A	30 seconds
B	3 minutes
C	10 minutes
D	5 minutes

4. - E1D08

Which VHF amateur service bands have frequencies available for space stations?

Select	Answer
A	6 meters and 2 meters
B	2 meters
C	2 meters and 1.25 meters
D	6 meters, 2 meters, and 1.25 meters

5. - E1E08

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

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

6. - E1F12

Who may be the control operator of an auxiliary station?

Select	Answer
A	Any licensed amateur operator
B	Only Technician, General, Advanced or Amateur Extra Class operators
C	Only Amateur Extra Class operators
D	Only General, Advanced or Amateur Extra Class operators

7. - E2A07

Which of the following types of signals can be relayed through a linear transponder?

Select	Answer
A	All of these choices are correct
B	PSK and Packet
C	SSB and SSTV
D	FM and CW

8. - E2B06

What is vestigial sideband modulation?

Select	Answer
A	A type of modulation in which one sideband is inverted
B	Amplitude modulation in which one complete sideband and a portion of the other are transmitted
C	Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier
D	Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

9. - E2C03

From which of the following bands is amateur radio contesting generally excluded?

Select	Answer
A	2 m
B	33 cm
C	6 m
D	30 m

10. - E2D13

What type of modulation is used for JT65 contacts?

Select	Answer
A	RTTY
B	Multi-tone AFSK
C	PSK
D	IEEE 802.11

11. - E2E01

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

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

12. - E3A02

What characterizes libration fading of an EME signal?

Select	Answer
A	A slow change in the pitch of the CW signal
B	A gradual loss of signal as the Sun rises
C	A fluttery irregular fading
D	The returning echo is several Hertz lower in frequency than the transmitted signal

13. - E3B01

What is transequatorial propagation?

Select	Answer
A	Propagation between two stations at the same latitude
B	Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
C	Propagation between any two points located on the magnetic equator
D	Propagation between two continents by way of ducts along the magnetic equator

14. - E3C15

What might a sudden rise in radio background noise indicate?

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

15. - E4A02

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

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

16. - E4B07

What do the subscripts of S parameters represent?

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

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

18. - E4D09

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

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

19. - E4E05

How can noise from an electric motor be suppressed?

Select	Answer
A	By installing a brute-force AC-line filter in series with the motor leads
B	By installing a high pass filter in series with the motor's power leads
C	By using a ground-fault current interrupter in the circuit used to power the motor
D	By installing a bypass capacitor in series with the motor leads

20. - E5A08

What is the phase relationship between the current through and the voltage across a series resonant circuit at resonance?

Select	Answer
A	The current leads the voltage by 90 degrees
B	The voltage and current are 180 degrees out of phase
C	The voltage and current are in phase
D	The voltage leads the current by 90 degrees

21. - E5B11

What is the phase angle between the voltage across and the current through a series RLC circuit if XC is 25 ohms, R is 100 ohms, and XL is 50 ohms?

Select	Answer
A	14 degrees with the voltage leading the current
B	76 degrees with the voltage leading the current
C	14 degrees with the voltage lagging the current
D	76 degrees with the voltage lagging the current

22. - E5C07

What is a vector?

Select	Answer
A	A quantity with both magnitude and an angular component
B	The inverse of the tangent function
C	The value of a quantity that changes over time
D	The inverse of the sine function

23. - E5D01

What is the result of skin effect?

Select	Answer
A	Thermal effects on the surface of the conductor decrease the impedance
B	Thermal effects on the surface of the conductor increase the impedance
C	As frequency increases, RF current flows in a thinner layer of the conductor, closer to the surface
D	As frequency decreases, RF current flows in a thinner layer of the conductor, closer to the surface

24. - E6A09

What is a depletion-mode FET?

Select	Answer
A	Any FET without a channel
B	An FET that has no current flow between source and drain when no gate voltage is applied
C	An FET that exhibits a current flow between source and drain when no gate voltage is applied
D	Any FET for which holes are the majority carriers

25. - E6B02

What is an important characteristic of a Schottky diode as compared to an ordinary silicon diode when used as a power supply rectifier?

Select	Answer
A	Less forward voltage drop
B	Enhanced carrier retention time
C	Controlled reverse avalanche voltage
D	Much higher reverse voltage breakdown

26. - E6C08

In Figure E6-5, what is the schematic symbol for a NAND gate?

Select	Answer
A	4
B	1
C	2
D	3

27. - E6D09

What devices are commonly used as VHF and UHF parasitic suppressors at the input and output terminals of a transistor HF amplifier?

Select	Answer
A	Butterworth filters
B	Electrolytic capacitors
C	Ferrite beads
D	Steel-core toroids

28. - E6E10

What is the packaging technique in which leadless components are soldered directly to circuit boards?

Select	Answer
A	Stripped lead
B	Virtual lead mounting
C	Direct soldering
D	Surface mount

29. - E6F03

What is the most common configuration of an optoisolator or optocoupler?

Select	Answer
A	A frequency modulated helium-neon laser
B	An amplitude modulated helium-neon laser
C	An LED and a phototransistor
D	A lens and a photomultiplier

30. - E7A08

What logical operation does an OR gate perform?

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

31. - E7B03

Which of the following components form the output of a class D amplifier circuit?

Select	Answer
A	A matched load resistor to prevent damage by switching transients
B	A high-pass filter to compensate for low gain at low frequencies
C	A low-pass filter to remove switching signal components
D	A temperature compensating load resistor to improve linearity

32. - E7C09

What is a Jones filter as used as part of an HF receiver IF stage?

Select	Answer
A	A special filter that emphasizes image responses
B	An automatic notch filter
C	A variable bandwidth crystal lattice filter
D	A filter that removes impulse noise E7C10 (B) Which of the following filters would be the best choice for use in a 2 meter repeater duplexer? A. A crystal filter B. A cavity filter C. A DSP filter D. An L-C filter

33. - E7D07

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

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

34. - E7E01

Which of the following can be used to generate FM phone emissions?

Select	Answer
A	A reactance modulator on the final amplifier
B	A balanced modulator on the audio amplifier
C	A balanced modulator on the oscillator
D	A reactance modulator on the oscillator

35. - E7F12

What digital process is applied to I and Q signals in order to recover the baseband modulation information?

Select	Answer
A	Quadrature mixing
B	Decimation
C	Signal conditioning
D	Fast Fourier Transform

36. - E7G04

What is meant by the term op-amp input offset voltage?

Select	Answer
A	The difference between the output voltage of the op-amp and the input voltage required in the immediately following stage
B	The differential input voltage needed to bring the open loop output voltage to zero
C	The potential between the amplifier input terminals of the op-amp in an open loop condition
D	The output voltage of the op-amp minus its input voltage

37. - E7H07

How can an oscillator's microphonic responses be reduced?

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

38. - E8A06

What is the approximate ratio of PEP-to-average power in a typical single-sideband phone signal?

Select	Answer
A	2.5 to 1
B	25 to 1
C	1 to 1
D	100 to 1

39. - E8B08

What describes Orthogonal Frequency Division Multiplexing?

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

40. - E8C10

What is an advantage of Gray code in digital communications where symbols are transmitted as multiple bits

Select	Answer
A	It has more resolution than simple binary
B	It increases security
C	It has more possible states than simple binary
D	It facilitates error detection

41. - E8D08

What parameter might indicate that excessively high input levels are causing distortion in an AFSK signal?

Select	Answer
A	Intermodulation Distortion (IMD)
B	Baud rate
C	Signal to noise ratio
D	Repeat Request Rate (RRR)

42. - E9A13

How much gain does an antenna have compared to a 1/2-wavelength dipole when it has 12 dB gain over an isotropic antenna?

Select	Answer
A	6.17 dB
B	9.85 dB
C	14.15 dB
D	12.5 dB

43. - E9B08

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

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

44. - E9C09

What is a G5RV antenna?

Select	Answer
A	A phased array antenna consisting of multiple loops
B	A multi-band trap antenna
C	A multi-band dipole antenna fed with coax and a balun through a selected length of open wire transmission line
D	A wide band dipole using shorted coaxial cable for the radiating elements and fed with a 4:1 balun

45. - E9D06

What happens to the bandwidth of an antenna as it is shortened through the use of loading coils?

Select	Answer
A	No change occurs
B	It is decreased
C	It becomes flat
D	It is increased

46. - E9E07

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

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

47. - E9F04

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

Select	Answer
A	2.70
B	0.10
C	0.66
D	0.30

48. - E9G06

On the Smith chart shown in Figure E9-3, what is the name for the large outer circle on which the reactance arcs terminate?

Select	Answer
A	Polar axis
B	Impedance axis
C	Prime axis
D	Reactance axis

49. - E9H11

What characteristic of a cardioid pattern antenna is useful for direction finding?

Select	Answer
A	A very sharp single null
B	High-radiation angle
C	Broad band response
D	A very sharp peak

50. - E0A04

When evaluating a site with multiple transmitters operating at the same time, the operators and licensees of which transmitters are responsible for mitigating over-exposure situations?

Select	Answer
A	Each transmitter that produces 5 percent or more of its MPE limit at accessible locations
B	Each transmitter operating with a duty-cycle greater than 50 percent
C	Only commercial transmitters
D	Only the most powerful transmitter

Figure E6-5

Figure E7-3

Figure E9-3