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

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1. - E1A04

With your transceiver displaying the carrier frequency of phone signals, you hear a DX station calling CQ on 3.601 MHz LSB. Is it legal to return the call using lower sideband on the same frequency?

Select	Answer
A	Yes, because the displayed frequency is within the 75 meter phone band segment
B	No, U.S. stations are not permitted to use phone emissions below 3.610 MHz
C	Yes, because the DX station initiated the contact
D	No, the sideband will extend beyond the edge of the phone band segment

2. - E1B07

What is the highest modulation index permitted at the highest modulation frequency for angle modulation below 29.0 MHz?

Select	Answer
A	1.0
B	0.5
C	2.0
D	3.0

3. - E1C09

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

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

4. - E1D01

What is the definition of the term telemetry?

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

5. - E1E11

What must the VE team do if an examinee scores a passing grade on all examination elements needed for an upgrade or new license?

Select	Answer
A	Issue the examinee the new or upgrade license
B	All these choices are correct
C	Photocopy all examination documents and forward them to the FCC for processing
D	Three VEs must certify that the examinee is qualified for the license grant and that they have complied with the administering VE requirements

6. - E1F05

Amateur stations may not transmit in which of the following frequency segments if they are located in the contiguous 48 states and north of Line A?

Select	Answer
A	420 MHz - 430 MHz
B	222 MHz - 223 MHz
C	440 MHz - 450 MHz
D	53 MHz - 54 MHz

7. - E2A06

On what band would a satellite receive signals if it were operating in mode U/V?

Select	Answer
A	29.5 MHz - 29.7 MHz
B	50.0 MHz - 50.2 MHz
C	435 MHz - 438 MHz
D	144 MHz - 146 MHz

8. - E2B15

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

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

9. - E2C10

Why might a DX station state that they are listening on another frequency?

Select	Answer
A	To improve operating efficiency by reducing interference
B	To separate the calling stations from the DX station
C	All of these choices are correct
D	Because the DX station may be transmitting on a frequency that is prohibited to some responding stations

10. - E2D03

Which of the following digital modes is especially useful for EME communications?

Select	Answer
A	Olivia
B	FSK441
C	JT65
D	PACTOR III

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	All of these choices are correct
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	Your transmit frequency is incorrect

12. - E3A01

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

Select	Answer
A	5000 miles, if the Moon is at perigee
B	12,000 miles, if the Moon is visible by both stations
C	2000 miles, if the Moon is at apogee
D	500 miles, if the Moon is at perigee

13. - E3B14

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

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

14. - E3C05

What orientation of Bz (B sub z) increases the likelihood that incoming particles from the Sun will cause disturbed conditions?

Select	Answer
A	Southward
B	Northward
C	Westward
D	Eastward

15. - E4A03

Which of the following test instrument is used to display spurious signals and/or intermodulation distortion products in an SSB transmitter?

Select	Answer
A	A spectrum analyzer
B	A wattmeter
C	A time-domain reflectometer
D	A logic analyzer

16. - E4B07

What do the subscripts of S parameters represent?

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

17. - E4C17

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

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

18. - E4D02

Which of the following describes two problems caused by poor dynamic range in a communications receiver?

Select	Answer
A	Cross-modulation of the desired signal and insufficient audio power to operate the speaker
B	Cross-modulation of the desired signal and desensitization from strong adjacent signals
C	Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband
D	Oscillator instability and severe audio distortion of all but the strongest received signals

19. - E4E09

What undesirable effect can occur when using an IF noise blanker?

Select	Answer
A	The audio frequency bandwidth of the received signal might be compressed
B	Nearby signals may appear to be excessively wide even if they meet emission standards
C	FM signals can no longer be demodulated
D	Received audio in the speech range might have an echo effect

20. - E5A17

What is the result of increasing the Q of an impedance-matching circuit?

Select	Answer
A	It has no effect on impedance matching
B	Matching bandwidth is decreased
C	Matching bandwidth is increased
D	Matching range is increased

21. - E5B03

What happens to the phase angle of a reactance when it is converted to a susceptance?

Select	Answer
A	It is shifted by 90 degrees
B	The susceptance phase angle is the inverse of the reactance phase angle
C	The sign is reversed
D	It is unchanged

22. - E5C16

Which point on Figure E5-2 best represents the impedance of a series circuit consisting of a 300 ohm resistor and a 19 picofarad capacitor at 21.200 MHz?

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

23. - E5D11

What is the power factor of an R-L circuit having a 60 degree phase angle between the voltage and the current?

Select	Answer
A	1.73
B	1.414
C	0.5
D	0.866

24. - E6A02

Which of the following semiconductor materials contains excess free electrons?

Select	Answer
A	Insulated gate
B	Bipolar
C	N-type
D	P-type

25. - E6B04

What type of semiconductor device is designed for use as a voltage-controlled capacitor?

Select	Answer
A	Zener diode
B	Silicon-controlled rectifier
C	Tunnel diode
D	Varactor diode

26. - E6C08

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

Select	Answer
A	2
B	3
C	1
D	4

27. - E6D07

What is the usable frequency range of inductors that use toroidal cores, assuming a correct selection of core material for the frequency being used?

Select	Answer
A	From approximately 10 Hz to no more than 3000 kHz
B	From a few kHz to no more than 30 MHz
C	From less than 20 Hz to approximately 300 MHz
D	From about 100 kHz to at least 1000 GHz

28. - E6E04

Which is the most common input and output impedance of circuits that use MMICs?

Select	Answer
A	300 ohms
B	50 ohms
C	450 ohms
D	10 ohms

29. - E6F13

What is a liquid crystal display (LCD)?

Select	Answer
A	A display utilizing a crystalline liquid and polarizing filters which becomes opaque when voltage is applied
B	A modern replacement for a quartz crystal oscillator which displays its fundamental frequency
C	A frequency-determining unit for a transmitter or receiver
D	A display that uses a glowing liquid to remain brightly lit in dim light

30. - E7A07

What logical operation does a NAND gate perform?

Select	Answer
A	It produces logic "0" at its output if some but not all inputs are logic "1"
B	It produces logic "0" at its output only when all inputs are logic "0"
C	It produces logic "0" at its output only when all inputs are logic "1"
D	It produces logic "1" at its output only when all inputs are logic "1"

31. - E7B13

In Figure E7-2, what is the purpose of R?

Select	Answer
A	Emitter load
B	Fixed bias
C	Collector load
D	Voltage regulation

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

33. - E7D07

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

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

34. - E7E03

How does an analog phase modulator function?

Select	Answer
A	By varying the tuning of a microphone preamplifier to produce AM signals
B	By varying the tuning of a microphone preamplifier to produce PM signals
C	By varying the tuning of an amplifier tank circuit to produce PM signals
D	By varying the tuning of an amplifier tank circuit to produce AM signals

35. - E7F16

How might the sampling rate of an existing digital signal be adjusted by a factor of 3/4?

Select	Answer
A	Interpolate by a factor of three, then decimate by a factor of four
B	Multiply each sample value by a factor of 3/4
C	Add 3 to each input value and subtract 4 from each output value
D	Change the gain by a factor of 3/4

36. - E7G06

Which of the following is the most appropriate use of an op-amp active filter?

Select	Answer
A	As a low-pass filter used between a transmitter and a transmission line
B	As an audio filter in a receiver
C	As a high-pass filter used to block RFI at the input to receivers
D	For smoothing power supply output

37. - E7H04

How is positive feedback supplied in a Colpitts oscillator?

Select	Answer
A	Through a tapped coil
B	Through link coupling
C	Through a capacitive divider
D	Through a neutralizing capacitor

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 frequency modulation technique which uses non-harmonically related frequencies
C	A digital modulation technique using subcarriers at frequencies chosen to avoid intersymbol interference
D	A bandwidth compression technique using Fourier transforms

40. - E8C08

How does ARQ accomplish error correction?

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

41. - E8D04

What is the primary effect of extremely short rise or fall time on a CW signal?

Select	Answer
A	The generation of key clicks
B	The generation of RF harmonics
C	Limits data speed
D	More difficult to copy

42. - E9A07

What is meant by antenna gain?

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

43. - E9B13

What does the abbreviation NEC stand for when applied to antenna modeling programs?

Select	Answer
A	Numeric Electrical Computation
B	Numerical Electromagnetic Code
C	National Electrical Code
D	Next Element Comparison

44. - E9C15

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

Select	Answer
A	The horizontal beam width decreases with height
B	The main lobe takeoff angle decreases with increasing height
C	The main lobe takeoff angle increases with increasing height
D	The horizontal beam width increases with height

45. - E9D04

Why should an HF mobile antenna loading coil have a high ratio of reactance to resistance?

Select	Answer
A	To swamp out harmonics
B	To maximize losses
C	To minimize the Q
D	To minimize losses

46. - E9E02

What is the name of an antenna matching system that matches an unbalanced feed line to an antenna by feeding the driven element both at the center of the element and at a fraction of a wavelength to one side of center?

Select	Answer
A	The gamma match
B	The stub match
C	The epsilon match
D	The delta match

47. - E9F11

What impedance does a 1/8 wavelength transmission line present to a generator when the line is open at the far end?

Select	Answer
A	A capacitive reactance
B	An inductive reactance
C	The same as the characteristic impedance of the line
D	The same as the input impedance of the final generator stage

48. - E9G11

How are the wavelength scales on a Smith chart calibrated?

Select	Answer
A	In fractions of transmission line electrical wavelength
B	In fractions of antenna electrical wavelength
C	In fractions of antenna electrical frequency
D	In fractions of transmission line electrical frequency

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	A very sharp peak
D	Broad band response

50. - E0A10

What toxic material may be present in some electronic components such as high voltage capacitors and transformers?

Select	Answer
A	Polychlorinated Biphenyls
B	Polymorphic silicon
C	Polytetrafluroethylene
D	Polyethylene

Figure E5-2

Figure E6-5

Figure E7-2

Figure E7-3